@phdthesis{Calvet, author = {Calvet, Wolfram}, title = {Pr{\"a}paration und in-situ Charakterisierung MBE-gewachsener Kupferindiumdisulfid-Schichten}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-000000242}, language = {de} } @article{HoffmannMikaloSchmeisser, author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Schmeißer, Dieter}, title = {Si(001) surface oxidation by N2O}, abstract = {Ultra-thin homogeneous oxynitride films are prepared on Si(001). The Si surface is cleaned in UHV by heating (flashing) and is exposed to different pressures of N2Oat altered temperatures. Thus oxynitride layers of different thickness and different properties are grown depending on the N2O pressure and the Si temperature. This isillustrated by a schematic diagram. The properties of the different oxynitride layers were studied by a combined photoemission electron microscopy (PEEM) andphotoelectron spectroscopy (PES) investigation using highly monochromatic synchrotron radiation. The amount of oxygen and nitrogen incorporated in the oxynitridelayers is determined from the PES measurements. The typical surface morphology for different preparation conditions is shown in PEEM images.}, language = {en} } @article{MikaloSchmeisser, author = {Mikalo, Ricardo Pablo and Schmeißer, Dieter}, title = {Electric contacts on conductive polymers: sodium on poly(3-hexylthiophene-2,5-diyl)}, abstract = {Sodium as a model contact with low work function on regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) films was investigated. The interface was studied by X-rayand ultraviolet photoelectron spectroscopy in the range of 0.13 up to 1.8 metal atoms per hexylthiophene unit. In the range of 0.13-0.26 sodium atoms per hexylthiophenering we find a change inthe surface potentials which is interpreted as a discharge of positive surface charges. Sodium exposures above 0.5 sodium atoms perhexylthiophene unit exhibit a reduction of the thiophene sulfur due to the formation of sodium sulfide and breaking of the thiophene ring.}, language = {en} } @article{YfantisPaloumpaSchmeisseretal., author = {Yfantis, Alexandros D. and Paloumpa, Ioanna and Schmeißer, Dieter and Yfantis, Alexandros D.}, title = {Novel corrosion-resistant films for Mg alloys}, abstract = {A novel method for the corrosion inhibition of Mg, alloys, based on the formation of a thin polyacrylic-polypyrrole film, is presented. The film was created after simpleimmersion of the samples in a specially formulated emulsion of polyacrylic and polypyrrole polymers. The synthesis conditions were studied, as well as the resultingcorrosion resistance of coated magnesium foils (AZ31) in terms of corrosion rate in neutral aqueous NaCl solutions. The relative ratio of polyacrylic polymer topolypyrrole was found to be important for the film properties. Furthermore, only in situ polymerisation of pyrrole in the polyacrylic emulsion can provide advancedcorrosion proper-ties in relatively thin films (2-5 mum). Blending of polypyrrole powder with the polyacrylic emulsion gives rise to thick films (20 mum) with reducedcorrosion-inhibition properties. The corrosion rate was only weakly dependent on the film thickness of these novel coatings. We argue that the mechanism of corrosioninhibition is related to the formation of a thin passive layer of chemisorbed polypyrrole polymers or oligomers on the native magnesium oxide of the C surface. Thestructure is further stabilised by polyacrylic polymer chains interacting as dopants of polypyrrole. The method is environmentally friendly: non-toxic chemicals are used,no rinsing is required, etc. The advanced corrosion-inhibition properties of the films. as well as the simple application process on the metal surface, provide significantpotential for the industrial application of the method.}, language = {en} } @misc{AggourStoerkelMurrelletal., author = {Aggour, Mohammed and Stoerkel, Ulrich and Murrell, Chris and Campbell, S. A. and Jungblut, H. and Hoffmann, Patrick and Mikalo, Ricardo Pablo and Schmeißer, Dieter and Lewerenz, Hans-Joachim}, title = {Electrochemical interface modification of CuInS2 thin films}, abstract = {We studied two novel electrochemical treatments of CuInS2 solar-cell absorber films, introduced to remove the deleterious segregated CuS phase. Their influence onsurface topography, chemistry and electronic properties was investigated using in situ atomic force microscopy (AFM) and photoclectron spectroscopy, performed inpart at the U49/2 undulator beam line at BESSY II. The results are examined in order to develop an improved understanding of the chemical-electrochemical surfacetransformation processes.}, language = {en} } @article{HoffmannMikaloSchmeisser, author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Schmeißer, Dieter}, title = {PEEM - a spectromicroscopic tool for mc-Si surface evaluation}, abstract = {The photo emission electron microscope (PEEM) with its direct imaging of the sample surface is a convenient tool for fast evaluation of large sample areas. It is possibleto handle samples with a size of 30 mm x 30 mm.With PEEM it is possible to visualise grain boundaries and crystal displacements without removing the native oxide. No special sample treatment is needed exceptchemical polishing of the sample surface and a HF-dip to obtain a thin (1 ... 2 nm) oxide layer.The quality of that oxide was proofed by high resolution photo electron spectroscopy (PES) at a synchrotron. The results were compared to native oxide onsingle-crystalline Si and no suboxides (e.g. SiO) were found. Our spectromicroscopic PEEM measurements show no difference in the oxide qualities of different grainsand on grain boundaries or crystal displacements. Furthermore no difference in the binding energy of Si2p core levels were found.In addition to grain boundaries other spot-like features were found on the sample surface. These could be identified in some cases as precipitation of Ca underneath thenative oxide.}, language = {en} } @misc{MuellerHenkelMikaloetal., author = {M{\"u}ller, Klaus and Henkel, Karsten and Mikalo, Ricardo Pablo and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Elektronik mit organischen Materialien}, publisher = {BTU Cottbus, Eigenverlag}, abstract = {Plastikelektronik, flexible Solarzellen, intelligente Kleidung, neuartige und maßgeschneiderte Transducer f{\"u}r die Gas-, Fl{\"u}ssigkeits- und Biosensorik, all dies sind Anwendungen, die ohne halbleitende Polymere nicht denkbar w{\"a}ren und die Bereiche erschließen, in denen zur Zeit eine regelrechte Goldgr{\"a}berstimmung herrscht. Mit wichtigen Beitr{\"a}gen im Grundlagen- und Anwendungsbereich nimmt die BTU Cottbus an dieser Entwicklung teil, u. a. auch durch eine Kooperation mit dem Institut f{\"u}r Mikrobiologie des Carl-Thiem-Klinikums Cottbus.In diesem Artikel werden die Voraussetzungen f{\"u}r die Konstruktion organischer Feldeffekt-Transistoren mit gassensitiver Gate-Elektrode vorgestellt. Untersuchungen zur elektronischen Struktur des organischen Halbleiters Poly(3-Hexylthiophen), die Anwendung dieses Materials als aktive Schicht in organischen Feldeffekt-Transitoren, die Gassensitivit{\"a}t von Polypyrrolelektroden auf Quarz-Mikrowaagen und die Mikrorstukturierung organischer Elektroden werden beschrieben.}, language = {de} } @incollection{SchwiertzHenkelPaloumpaetal., author = {Schwiertz, Carola and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Sensorsystem zur Unterscheidung von Geruchsmustern in Tierst{\"a}llen}, abstract = {Es wurde ein kontinuierlich arbeitendes, preiswertes Schwingquarz-Mess-System zur olfaktometrischen {\"U}berwachung von Tierst{\"a}llen aufgebaut, mit dessen Hilfe im Arbeitsbereich von 65\%B0C spezifische Ger{\"u}che verschiedener Tierarten unterschieden werden k{\"o}nnen. Zur Geruchsmustererkennung wurde ein einfaches neuronales Netz verwendet. Olfaktometrische Verd{\"u}nnungen auf 33\% sowie Messwertschwankungen von 5-10\% wurden simuliert, wobei die richtige Musterzuordnung durch das Netz nicht beeinflusst wurde.}, language = {de} } @incollection{HenkelHoffmannSchmeisser, author = {Henkel, Karsten and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Backpropagation-Netzwerke f{\"u}r ein Zweisensorsystem zur Erfassung von Kohlendioxidkonzentrationen und relativer Luftfeuchte}, series = {Sensoren im Fokus neuer Anwendungen : Verbraucherschutz und Lebensmittelkontrolle, Biosysteme und Nanobiotechnologie, Umweltmesstechnik, neue Sensormaterialien, Mess- und Eichwesen}, booktitle = {Sensoren im Fokus neuer Anwendungen : Verbraucherschutz und Lebensmittelkontrolle, Biosysteme und Nanobiotechnologie, Umweltmesstechnik, neue Sensormaterialien, Mess- und Eichwesen}, publisher = {w.e.b. Universit{\"a}tsverlag}, address = {Dresden}, isbn = {3-935712-71-5}, pages = {104 -- 107}, abstract = {Zwei Schwingquarzsensoren mit gleicher sensitiver Beschichtung wurden zur Messung von CO2-Konzentrationen bei variierenden Luftfeuchten genutzt. Die Daten wurden neuronalen Netzen mit unterschiedlicher Architektur trainiert. Zwei Netze wurden auf ihre Generalisierungsf{\"a}higkeit getestet und miteinander verglichen. F{\"u}r ein einstufiges Netz konnten Ergebnisse mit Fehlern kleiner 12\% f{\"u}r die CO2-Konzentration und kleiner 5\% f{\"u}r die Luftfeuchte erzielt werden. Ein zweistufiges Netz erkannte Kategorien der Luftfeuchte 100\%-ig, f{\"u}r die CO2-Konzentration wurden Fehler kleiner 9\% erreicht, wobei eine deutlich bessere Generalisierungsf{\"a}higkeit dieses Netzes im Vergleich zum einstufigen Netz zu verzeichnen ist.}, language = {de} } @inproceedings{MuellerHenkelPaloumpaetal., author = {M{\"u}ller, Klaus and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Low-cost-Plot-Technologie fur die Mikrostrukturierung von Gassensoren}, series = {Sensoren im Fokus neuer Anwendungen, 5. Dresdner Sensor-Symposium, 10. - 12. Dezember 2001, Dresden}, booktitle = {Sensoren im Fokus neuer Anwendungen, 5. Dresdner Sensor-Symposium, 10. - 12. Dezember 2001, Dresden}, publisher = {w.e.b. Universit{\"a}tsverlag}, address = {Dresden}, isbn = {3-935712-71-5}, pages = {166 -- 169}, abstract = {Bei der Herstellung von Mikrosensoren ist die Strukturierung von Elektroden oder elektrischen Zu-leitungen mit einem hohen Miniaturisierungsgrad ein entscheidender Punkt. Dazu m{\"u}s-sen h{\"a}ufig teure Verfahren (Lithographie, Maskentechniken) herangezogen werden.Dieser Beitrag beschreibt eine low-cost-Technologie zur Herstellung organischer Mikrostrukturen f{\"u}r elektronische und messtechnische Anwendungen im Bereich der Sensorik. Geplottete Strukturen mit Polypyrrol und Poly(3,4-Ethylen-Dioxy-Thiophen), dotiert mit Polystyrolsulfonat (PEDOT/PSS) wurden als Widerstandssensoren f{\"u}r die Detektion von Luftfeuchte ein-gesetzt. Die prinzipielle Ein-satzm{\"o}glichkeit unserer Technik im Bereich der organischen Elektronik konnten wir mit dem Bau organischer Feldeffekttransistoren nachweisen. Mit einem computergesteu-erten Plotter des Typs Rol-land DXY-1150A, Plot-Kapillaren f{\"u}r das Tuschezeichnen, handels{\"u}blichen Folien f{\"u}r wasserl{\"o}sliche Tinten als Substrat und kolloidalen Graphit als leitendes Material konnten wir Aufl{\"o}sungen, das heißt insbesondere Kanalbreiten bzw. Elektrodenabst{\"a}nde im Bereich von 20+10\%B5m (auf 2cm L{\"a}nge) her-stellen.}, language = {de} } @article{MuellerHoffmannMilkoetal., author = {M{\"u}ller, Klaus and Hoffmann, Patrick and Milko, S. and Burkov, Yevgen and Schmeißer, Dieter}, title = {PEEM and µ-NEXAFS of Cu-In-S-Surfaces}, abstract = {The composition of CuInS2-films tends to differ from the ideal ratio of 1:1:2. A molecularlyvariation of dm=[Cu]/[In]-1 not equal 0 occurs due to the formation of binary phases as segregation's at the surface, as crystallites in the bulk of the film or at the surface of grains [1]. Furthermore, the range of homogeneity of the phase CuInS2 is relatively large caused by a low enthalpy of formation of defects like Cu-vacancies [2]. Segregation's at surfaces can be removed by KCN etching or by an electrochemical process [3, 4] We investigated the effect of an in-situ-heat-treatment of samples, prepared in the Cu-rich regime with additional amounts of copper, deposited on the surface of the Cu-In-S-films.We used Cu-In-S-films on molybdenum, prepared from precursors of Cu/In and a following reactive annealing-process in a sulphur-atmosphere. The experiments were performed as follows: The surface of the films was cleaned in situ to remove CuS-Phases by Argon-bombardment. The thin layers of additional Copper were prepared by evaporation of copper metal in Knudsen-cells. The thickness of this copper-films is in the range of monolayers, revealed by a calibration with copper on iron-substrates. After this deposition the samples were heated up to several temperatures (up to 550 ºC) for ten minutes, respectively. Here the molybdenum back-contact was used as electrical heater.}, language = {en} } @article{BatchelorHoffmannSchmeisser, author = {Batchelor, David R. and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Photoemission study of Aluminium Steel cold welded joints}, abstract = {Aluminium and Stainless Steel bi-metal material is extremely versatile and is used in a wide range of products; from cooking utensils to high technology applications such as automobile manufacture and Synchrotron radiation instrumentation. As a consequence of this wide range of applications the study of the formation of Aluminium Steel junctions and the bonding mechanism is of considerable industrialimportance [1-3].In a previous publication [4] evidence for a chemical bond, alloying at the interface was found. As the monochromator focus and welded region are similar in size about 200 µm (the actual interface from SEM is an order of magnitude smaller) a simple photoemission experiment of translating the sample perpendicular (vertically, weld horizontal) to the weld and measuring spectra was performed.}, language = {en} } @article{JaeckelThissenHungeretal., author = {J{\"a}ckel, B. and Thißen, A. and Hunger, Ralf and Klein, A. and Jaegermann, Wolfram and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Focus IS-PEEM investigations at U49/II: experimental determination of a magnification function, the contrast mechanism and the spectral resolution}, language = {en} } @incollection{SchmeisserHoffmannMuessig, author = {Schmeißer, Dieter and Hoffmann, Patrick and M{\"u}ssig, Hans-Joachim}, title = {The Pr2O3/Si(001) interface: a mixed Si-Proxide}, series = {BESSY annual report 2001}, booktitle = {BESSY annual report 2001}, publisher = {Bessy}, address = {Berlin}, pages = {171 -- 173}, language = {en} } @article{SchmeisserHoffmann, author = {Schmeißer, Dieter and Hoffmann, Patrick}, title = {Characterisation of the PrOx/Si(001) Interface by Photoelectron Spectroscopy}, language = {en} } @article{SeyllerSieberGraupneretal., author = {Seyller, Th. and Sieber, N. and Graupner, R. and James, D. and Riley, J. and Leckey, R. and Polcik, M. and Schmeißer, Dieter}, title = {High Resolution Photoelectron Spectroscopy on SiC Surfaces}, language = {en} } @article{PopWinterBatcheloretal., author = {Pop, D. and Winter, B. and Batchelor, David R. and Freyer, W. and Weber, R. and Br{\"o}cker, D. and Hertel, I. V. and Schmeißer, Dieter and Widdra, Wolf}, title = {Copper Satellite Structure in Porphyrazine Compounds}, language = {en} } @article{GraciaMartinConcepcionBarrancoetal., author = {Gracia, F. and Martin-Concepcion, A. I. and Barranco, A. and Holgado, J. P. and Espinos, J. P. and Yubero, F. and Batchelor, David R. and Schmeißer, Dieter and Gonzalez-Elipe, A. R.}, title = {XAS investigation of texture in TiO2 thin films prepared by IBICVD}, language = {en} } @misc{LopezHellerBitzeretal., author = {Lopez, Alberto and Heller, Thomas and Bitzer, Thomas and Richardson, Neville V.}, title = {A vibrational study of the adsorption of glycine on clean and Na modified Si (100)-2x1 surfaces}, series = {Chemical physics}, volume = {277}, journal = {Chemical physics}, number = {1}, issn = {0301-0104}, pages = {1 -- 8}, abstract = {The chemisorption of glycine and its fully deuterated analogue, d(5)-glycine, deposited on the clean and Na modified Si(100)-2 x 1 surfaces, has been studied byhigh-resolution electron energy loss spectroscopy (HREELS) and ab initio methods. HREELS indicates that chemisorption of glycine and d(5)-glycine on Na/Si(100)-2 x1 occurs through cleavage of the OH and OD bonds in the carboxylic groups. The adsorbed species are bonded through the formation of an ionic bond between thedeprotonated carboxylate group and the adsorbed Na atom, leading to species in a bidentate coordination. In contrast, we observe monodentate glycinate andd(5)-glycinate species following the exposure of Si(100)-2 x 1 to glycine and deuterated glycine. The thermal stability of glycine on clean Si(100)-2 x 1 and on the Namodified surface has been studied by heating the substrate to various temperatures.}, language = {en} } @misc{BeerbomMayerJaegermannetal., author = {Beerbom, Martin and Mayer, Thomas and Jaegermann, Wolfram and Batchelor, David R. and Schmeißer, Dieter}, title = {Synchrotron-induced photoemission of GaAs electrodes after electrochemical treatment in aqueous electrolytes}, abstract = {Electrochemically-induced oxidation and reduction reactions of UHV-cleaved GaAs(110) surfaces have been studied after emersion under potential control using highresolution synchrotron-induced photoelectron spectroscopy. High quality spectra of the As and Ga core 3d lines and the valence band region have been obtained. Thespectra of the anodic oxide show strong emission of bulk-like Ga2O3 and some As2O3 with the admixture of suboxides and hydroxides. Ga2O3 and As2O3 arecathodically reduced leaving the GaAs surface covered mostly with elemental As, some As-H and remnants of Ga-suboxides and -hydroxides.}, language = {en} } @article{SieberSeyllerGraupneretal., author = {Sieber, N. and Seyller, Th. and Graupner, R. and Ley, L. and Mikalo, Ricardo Pablo and Hoffmann, Patrick and Batchelor, David R. and Schmeißer, Dieter}, title = {Wet-chemical preparation of silicate adlayer reconstructed SiC(0001) surfaces as studied by PIES and LEED}, abstract = {We have studied the surface chemistry of 6H-SiC(0001) and 6H-SiC (000 (1) over bar) after wet-chemical treatment using photoelectron spectroscopy (PES) andlow-energy electron diffraction (LEED). The origin of chemically shifted components in the Si2p and C1s spectra is discussed in the light of previous studies onwet-chemically prepared surfaces and on silicate adlayer reconstructed surfaces. On 6H-SiC(0001) an ordered silicate adlayer was prepared by etching the surface withsulfuric acid based agents.}, language = {en} } @misc{LewerenzAggourMurrelletal., author = {Lewerenz, Hans-Joachim and Aggour, Mohammed and Murrell, Chris and Kanis, M. and Hoffmann, Patrick and Jungblut, H. and Schmeißer, Dieter}, title = {Interface engineering of photoelectrochemically prepared Si surfaces}, abstract = {The oxide of Si(111) formed by electropolishing in dilute ammonium fluoride solution is analysed by photoelectron spectroscopy using synchrotron radiation. The oxidiclayer is about 3.1 nm thick and contains Si-F-x species as well as oxyfluorides. The oxyfluorides are found preferentially at the electropolishing layer surface. SiOHspecies are concentrated at the oxidic film/substrate interface. The full width half maximum of the Si 2p line indicates that the Si/electropolishing oxide interface issmoother than the Si/natural oxide interface.}, language = {en} } @phdthesis{Goryachko, author = {Goryachko, Andriy}, title = {Investigations of perspective materials for aggressively scaled gate stacks and contact structures of MOS devices}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-000000342}, language = {en} } @article{BatchelorFollathSchmeisser, author = {Batchelor, David R. and Follath, Rolf and Schmeißer, Dieter}, title = {Commissioning Results of the BTUC-PGM beamline}, language = {en} } @misc{BoehmeLloydSpetzLundstroemetal., author = {B{\"o}hme, O. and Lloyd Spetz, Anita and Lundstr{\"o}m, Ingemar and Schmeißer, Dieter}, title = {Nanoparticles as the Active Element of High-Temperature Metal-Insulator-Silicon Carbide Gas Sensors}, series = {Advanced Materials}, volume = {13}, journal = {Advanced Materials}, number = {8}, issn = {1521-4095}, pages = {597 -- 601}, language = {en} } @misc{GuerekAppelMikaloetal., author = {G{\"u}rek, A. G. and Appel, G{\"u}nter and Mikalo, Ricardo Pablo and Schmeißer, Dieter}, title = {Synthesis of dihydroxy silicon phthalocyanine tetrasulfonic acid and poly-µ-oxo silicon phthalocyanine tetrasulfonic acid}, series = {Journal of Porphyrins and Phthalocyanines}, volume = {5}, journal = {Journal of Porphyrins and Phthalocyanines}, number = {10}, issn = {1099-1409}, pages = {751 -- 757}, language = {en} } @misc{HenkelOpreaPaloumpaetal., author = {Henkel, Karsten and Oprea, A. and Paloumpa, Ioanna and Appel, G{\"u}nter and Schmeißer, Dieter and Kamieth, P.}, title = {Selective polypyrrole electrodes for quartz microbalances : NO2 and gas flux sensitivities}, series = {Sensors and Actuators : B, Chemical 76(2001)1-3}, volume = {76}, journal = {Sensors and Actuators : B, Chemical 76(2001)1-3}, number = {1-3}, issn = {0925-4005}, pages = {124 -- 129}, language = {en} } @misc{HoffmannMikaloYfantisetal., author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Yfantis, Alexandros D. and Batchelor, David R. and Appel, G{\"u}nter and Schmeißer, Dieter}, title = {A Spectro-Microscopic Approach for Thin Film Analysis Grain Boundaries in mc-Si and Sn/SnO2 Nano Particles}, series = {Microchimica Acta}, volume = {136}, journal = {Microchimica Acta}, number = {3-4}, issn = {1436-5073}, pages = {109 -- 113}, language = {en} } @article{LopezBitzerHelleretal., author = {Lopez, A. and Bitzer, Thomas and Heller, Thomas and Richardson, Neville V.}, title = {Adsorption of water on alkoxy modified Si(1 0 0), Si(1 1 3) and Si(1 1 5) surfaces}, language = {en} } @article{LopezBitzerHelleretal., author = {Lopez, A. and Bitzer, Thomas and Heller, Thomas and Richardson, Neville V.}, title = {Adsorption of maleic anhydride on Si(1 0 0)-2 x 1}, series = {Surface Science}, volume = {477}, journal = {Surface Science}, issn = {0039-6028}, pages = {219 -- 226}, language = {en} } @article{MikaloAppelHoffmannetal., author = {Mikalo, Ricardo Pablo and Appel, G{\"u}nter and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Band Bending in Doped Conducting Polypyrrole Interaction with Silver}, language = {en} } @article{MikaloAppelSchmeisser, author = {Mikalo, Ricardo Pablo and Appel, G{\"u}nter and Schmeißer, Dieter}, title = {Conductivity of Silver exposed Polypyrrole Films}, language = {en} } @article{MikaloHoffmannBatcheloretal., author = {Mikalo, Ricardo Pablo and Hoffmann, Patrick and Batchelor, David R. and Schmeißer, Dieter and Lloyd Spetz, Anita and Lundstr{\"o}m, Ingemar}, title = {Comparison of HF and ozone treated SiC surfaces}, language = {en} } @article{SchmeisserMikaloHoffmannetal., author = {Schmeißer, Dieter and Mikalo, Ricardo Pablo and Hoffmann, Patrick and Seyller, Th. and Ley, L. and Lloyd Spetz, Anita}, title = {Oxide growth on SiC (0001) surfaces}, language = {en} } @article{SieberMantelSeylleretal., author = {Sieber, N. and Mantel, B. F. and Seyller, Th. and Ristein, J. and Ley, L. and Heller, Thomas and Batchelor, David R. and Schmeißer, Dieter}, title = {Electronic and chemical passivation of hexagonal 6H-SiC surfaces by hydrogen termination}, language = {en} } @inproceedings{BatchelorBergSimonetal., author = {Batchelor, David R. and Berg, A. and Simon, Sylvio and Wagner, Lothar and Viehweger, Bernd and Schmeißer, Dieter}, title = {Development of Joining Techniques through Pressforming of Steel and Aluminium}, language = {en} } @inproceedings{HenkelEllingDanzetal., author = {Henkel, Karsten and Elling, B. and Danz, R. and B{\"u}chtemann, A. and Straube, Oliver and Paloumpa, Ioanna and Yfantis, Alexandros D. and Schmeißer, Dieter}, title = {Piezoelectric polymer sensor for high pressures in forming machines}, language = {en} } @inproceedings{HuleaHoffmannBrinzaetal., author = {Hulea, Iulian and Hoffmann, Patrick and Brinza, Monica and Batchelor, David R. and Schmeißer, Dieter}, title = {The interface of friction-welded Al-Fe joints. ATB Metallurgy}, language = {en} } @inproceedings{JaegermannSchmeisser, author = {Jaegermann, Wolfram and Schmeißer, Dieter}, title = {Elementary Processes at Solid/Electrolyte Interfaces}, language = {en} } @inproceedings{YfantisTsiniarakisLabrakopoulosetal., author = {Yfantis, Alexandros D. and Tsiniarakis, G. and Labrakopoulos, S. and Yfantis, Alexandros D. and Schmeißer, Dieter}, title = {Conductive polymers of pyrrole as pigments in organic anticorrosive coatings-application for aluminium alloys}, language = {en} } @phdthesis{Schweizer, author = {Schweizer, Stefan}, title = {Dynamisches Verhalten von Silizium-Elektroden in Fluor-haltigen Elektrolyten}, publisher = {Brandenburgische Techn. Univ.}, address = {Cottbus}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-000000526}, language = {de} } @misc{LewerenzAggourMurrelletal., author = {Lewerenz, Hans-Joachim and Aggour, Mohammed and Murrell, Chris and Kanis, M. and Jungblut, H. and Jakubowicz, J. and Cox, P. A. and Campbell, S. A. and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Initial stages of structure formation on silicon electrodes investigated by photoelectron spectroscopy using synchrotron radiation and in-situ atomic force microscopy}, series = {Journal of the Electrochemical Society}, volume = {150}, journal = {Journal of the Electrochemical Society}, number = {3}, issn = {1945-7111}, pages = {E185 -- E189}, abstract = {The surface condition of electrochemically H-terminated Si is compared with the situation at the first photocurrent maximum in dilute acidic ammonium fluoride solution where the divalent dissolution converts into the four-valence process. The first high spectral-resolution photoelectron spectroscopy data using synchrotron radiation of electrochemically hydrogenated Si are presented. A combined electrochemistry/ultrahigh vacuum surface analysis system, attached to the U 49/2 beamline at the synchrotron Bessy II, is used for photoelectron spectroscopy (PES) of the electrochemically conditioned samples. We analyze the Si 2p, O 1s, and F 1s core levels. A comparison of a density functional theory calculation of the reaction sequence, proposed in the dissolution model of Gerischer and co-workers, with the PES results supports this model. The anodized sample is characterized by a residual H coverage of 0.35 monolayers evidenced by a surface core level shift, Si-OH and Si-Fx species, F-, and a higher oxidized Si species. SiO2 is not found. Even on very well H-terminated surfaces, we find residual Si-OH complexes, fluoride and water. In situ atomic force microscopy shows a roughening with a root mean square roughness parameter of 2.6 nm. \%A92003 The Electrochemical Society. All rights reserved.}, language = {en} } @misc{HoffmannSchmeisserRotersetal., author = {Hoffmann, Patrick and Schmeißer, Dieter and Roters, G. and Nenyei, Z.}, title = {Non-destructive probing of interfacial oxidation and nitridation states at RTA Si-oxides}, series = {Thin Solid Films}, volume = {428}, journal = {Thin Solid Films}, number = {1-2}, issn = {0040-6090}, pages = {216 -- 222}, abstract = {The quality of the SiO2/Si interface is of crucial importance in the development and performance of sub 0.1 small mu, Greekm technologies. The knowledge of the chemical composition of the interface is an important piece of information in the preparation of ultra-thin oxides and high-k dielectrics, in order to maintain a high-quality interface and channel mobility. Here we report on investigations of 2 nm oxide layers formed by a RTP process under various gas mixtures containing N2O and NH3 at different concentrations. We studied the SiO2/Si(001) interface by a non-destructive depth profiling using Synchrotron radiation photoelectron spectroscopy. We determine the thickness of the oxide layer, the relative content and chemical state of nitrogen within the oxide, the thickness of the interface layer, and the relative abundance of Si intermediate oxides within. In all systems we find the thickness of the intermediate layer to be approximately 0.17 nm. The intermediate layer contains Si atoms in the oxidation states +1, +2 and +3 with similar relative abundance. Nitrogen is found predominantly close to the intermediate layer forming Si---N as well as Si---N---O bonds. Within the oxide there are only spurious nitrogen content with predominately Si---N---O bonds. Our method is able to detect a nitrogen content within the intermediate layer as low as approximately 5\%.}, language = {en} } @article{SchmeisserPaloumpaHoffmannetal., author = {Schmeißer, Dieter and Paloumpa, Ioanna and Hoffmann, Patrick and Burkov, Yevgen and Yfantis, Alexandros D. and Yfantis, Alexandros D.}, title = {Preventing Corrosion of Aluminium Alloys by Polymeric Coatings}, abstract = {Aluminium is a material of everyday use in many applications,like automobile,aero-space or cookware,due to its specialproperties (low density,low weight,strength,easy to form and cast,abundance etc).Although aluminium is a reactive metal,italso has a significant corrosion resistance because of a thin,protective oxide layer which is generally stable in air and aqueous solutions.However,pores within the oxide film and other defects caused from alloying elements can lead to local corrosion and the formation of pits.}, language = {en} } @article{MuellerMilkoSchmeisser, author = {M{\"u}ller, Klaus and Milko, S. and Schmeißer, Dieter}, title = {Preparation of stoichiometric CuInS2-surfaces - an XPS, UPS-study}, series = {Thin Solid Films}, volume = {431-432}, journal = {Thin Solid Films}, issn = {0040-6090}, pages = {312 -- 316}, abstract = {CuInS2 films are investigated with photoelectron spectroscopy. We find significant deviation from the stoichiometric composition depending on the preparation on the films. For Cu-rich films (start composition) we show that by Ar sputtering and annealing the surface composition varies along a binary cut of the Cu-In-S ternary phase diagram. We also present a novel technique which brings the surface composition close to the stoichiometric stability range of the CuInS2 phase. The technique used the evaporation of Cu on the sputter cleaned surface.}, language = {en} } @misc{MuellerBurkovSchmeisser, author = {M{\"u}ller, Klaus and Burkov, Yevgen and Schmeißer, Dieter}, title = {PEEM and my-NEXAFS of Cu-In-S2-surfaces}, series = {Thin Solid Films}, volume = {431-432}, journal = {Thin Solid Films}, issn = {0040-6090}, pages = {307 -- 311}, abstract = {Polycrystalline CuInS2 samples are an ideal system for photoemission electron microscope studies. The polycrystalline grains have a diameter of approximately 5 small mu, Greekm and the system is expected to be highly inhomogeneous because of the existence of many sub-phases. We used a recently established procedure to reproducibly obtain stoichiometric CuInS2-surfaces and follow the changes in the morphology, the elemental inhomogeneous distribution, and the development of the electronic structure upon its preparation. We find that the individual grains trend to coagulate, the surface composition becomes more homogeneous, and identify characteristic features of the unoccupied DOS.}, language = {en} } @misc{Schmeisser, author = {Schmeißer, Dieter}, title = {Valence states of poly(3-hexyl-thiophene) as probed by photoelectron spectra at resonant excitation}, series = {Synthetic Metals}, volume = {138}, journal = {Synthetic Metals}, number = {1-2}, issn = {0379-6779}, pages = {135 -- 140}, abstract = {Photoelectron spectroscopy employing synchrotron radiation is applied to learn about the electronic structure of regio-regular poly(3-hexyl-thiophene) (P3hT). We study the valence band photoelectron spectra around the carbon 1s threshold. This technique is equivalent to resonant excitation of core electrons into empty valence states. We probe the properties of these carriers in the conduction band and also learn about valence band states involved in the carbon (K L L) Auger transitions. The data give evidence that monomeric orbital energies are dominating in such processes. We conclude that poly(3-hexyl-thiophene) is a polymer with a rather short conjugation length.}, language = {en} } @misc{MuellerPaloumpaSchmeisser, author = {M{\"u}ller, Klaus and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Carbon-plot-microstructuring for all-polymer-transistors}, series = {Synthetic Metals}, volume = {138}, journal = {Synthetic Metals}, number = {1-2}, issn = {0379-6779}, pages = {271 -- 273}, abstract = {This contribution describes the use of a low-cost technology to produce organic microstructures for electronically applications. With a computer driven plotter, substrates like printing foil and colloidal graphite (diluted in water) for the electrodes, we realised channel lengths of 20±10 microm. Compared with transistor devices, fabricated using conventional photolithographic methods and the same semiconducting material, this technique is a hopeful approach to produce microelectronic structures that are low-cost and all-organic.}, language = {en} } @article{Baer, author = {B{\"a}r, Werner}, title = {Schnelle Biosensorik f{\"u}r die medizinische Diagnostik}, abstract = {In diesem Beitrag beschreiben wir ein gemeinsames Forschungsvorhaben, welches den Einsatz neuartiger Sensortypen in der medizinischen Diagnostik zum Inhalt hat.Diese Sensoren sollen komplett organisch sein und auf dem Prinzip des Feldeffekttransistors basieren. Die Vorteile des organischen Aufbaus liegen auf der Hand: Die organischen Komponenten sind billiger herzustellen und zu handhaben als anorganische, k{\"o}nnen leichter chemisch durch Funktionalisierung modifiziert werden und k{\"o}nnen sogar in-vitro eingesetzt werden. Anderseits bietet das Prinzip des Feldeffekttransistors neben einer ca. 1000-fachen Verst{\"a}rkung der Messsignale die M{\"o}glichkeit, simultan verschiedene physikalisch-chemische Wechselwirkungsprozesse des Analytenmit dem Polymer auszuwerten (siehe Forum, Heft 13).Als Modellsystem f{\"u}r die Anwendung in der Biosensorik soll die Einsatzm{\"o}glichkeit dieser Sensoren in der Nicht-invasiven Diagnostik der Helicobacter pylori- Infektion {\"u}berpr{\"u}ft werden. Zum Einen existieren hier andere Nachweisverfahren, die als Validierung dienen k{\"o}nnen, aber den Nachteil haben, das sie relativ teuer und langwierig sind. Zum anderen h{\"a}tte die Sensorik mit einem Transistor, dem Grundbaustein mikroelektronischer Schaltungen, den Vorteil, daß die Messung direkt, also online erfolgen k{\"o}nnte.}, language = {de} } @misc{RiessSchmeisser, author = {Riess, W. and Schmeißer, Dieter}, title = {Organic Materials for Device Applications - Preface}, series = {Synthetic Metals}, volume = {138}, journal = {Synthetic Metals}, number = {1-2}, issn = {0379-6779}, pages = {S. 1}, language = {en} } @misc{SchmeisserPresselYamamotoetal., author = {Schmeißer, Dieter and Pressel, Klaus and Yamamoto, Yuji and Tillack, Bernd and Kr{\"u}ger, D.}, title = {Ge instabilities near interfaces in Si-SiGe-Si heterostructures}, series = {Materials Science \& Engineering B}, volume = {101}, journal = {Materials Science \& Engineering B}, number = {1-3}, issn = {0921-5107}, pages = {208 -- 211}, abstract = {Compositional characterization of interfaces in Si-cap/SixGe1-x/Si heterostructures is an important topic in SiGe based advanced microelectronics and in quantum wells. Extremely high depth resolution is required to detect and optimize near-interface compositional gradients which are crucial for high circuit performance. We report on non-destructive, high-resolution, near-interface depth profiling using SR photoelectron spectroscopy at an undulator beamline. We measured the Ge content at the SixGe1-x interface towards the native SiO2 layer and investigated the influence of additional (1nm and 2nm) Si capping layers (Si-cap). For the uncapped samples we found near the oxide/ SiGe interface region a strong mixing of Ge-oxides and SiOx. This indicates a high instability of the Ge atoms at those interfaces while silicon capped (1nm, 2nm) SixGe1-x films are more stable. We detect sharp Ge concentration gradients within the first 1nm at the Si/SixGe1-x interface. These results open new possibilities for Ge profile optimization in Si-cap/SixGe1-x/Si heterostructures. In the Ge3d spectra we differentiate the Ge atoms to occupy three different lattice sites and are able to follow their relative occupation within the Ge gradient.}, language = {en} } @misc{SchmeisserMuessig, author = {Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim}, title = {The Pr2O3 / Si (001) interface studied by synchrotron radiation photo-electron spectroscopy}, series = {Solid State Electronics}, volume = {47}, journal = {Solid State Electronics}, number = {10}, issn = {0038-1101}, pages = {1607 -- 1611}, abstract = {Pr2O3 is currently under consideration as a potential replacement for SiO2 as the gate-dielectric material for sub-0.1micro m complementary metal-oxide-semiconductor (CMOS) technology. We studied the Pr2O3/Si(0 0 1) interface by a non-destructive depth profiling using synchrotron radiation photoelectron spectroscopy. Our data suggests that there is no silicide formation at the interface. Based on reported results, a chemical reactive interface exists, consisting of a mixed Si-Pr oxide such as (Pr2O3)x(SiO2)1?x, i.e. as a silicate phase with variable silicon content. This pseudo-binary alloy at the interface offers large flexibility toward successful integration of Pr2O3 into future CMOS technologies.}, language = {en} } @misc{SchmeisserIrmscherWagner, author = {Schmeißer, Dieter and Irmscher, Klaus and Wagner, Gerd}, title = {Photoelectron spectra of Al dopants in 4H-SiC}, series = {Materials Science \& Engineering B}, volume = {102}, journal = {Materials Science \& Engineering B}, number = {1-3}, issn = {0921-5107}, pages = {284 -- 288}, abstract = {Al-doped 4H-SiC epitaxial layers were grown in a hot-wall chemical vapor deposition (CVD) system on commercial 4H-SiC substrates (CREE). The incorporation of Aluminum has been studied in the concentration range from 2*1014cm-3 up to 3*1020cm-3. Epitaxial layers with doping concentration NA-ND> 1019cm-3 were studied by HV-TEM and synchrotron radiation investigations. In the concentration range from 1*1019cm-3 to 3*1020 cm-3, measured by SIMS and Hall investigations, no Aluminum precipitation were detected in the grown layers. For SiC samples with an Al concentration of 1020cm-3 we have been able to detect the Al2p photoemission signal. The Al2p signal is recorded through the oxide layer (thickness of about 0.4nm), it has a main contribution at a binding energy of 73eV which corresponds to the energy typical for elemental Al0. In spectra excited with higher photon energies the sampled photoelectrons originate from deeper layers. In these data we notice an additional shoulder in the Al2p signal at around 71eV. The evidence of two contributions is attributed to the fact that Al is incorporated at different lattice sites. As the latter data represent more bulk like properties we argue that Al in the bulk SiC occupies both, substitutional lattice sites and interstitial sites while in the surface near regions Al is found only at substitutional lattice sites.}, language = {en} } @article{Schmeisser, author = {Schmeißer, Dieter}, title = {Resonant photoemission at the Pr2O3 /Si(001) interface}, abstract = {In resonant photoemission studies photoelectron spectroscopy (PES) is done at photon ener-giesthat enable the excitation from a deep core hole to the empty conduction band states. Atresonant condition only such states are selectively enhanced which allow an optical couplingof the core hole to the empty conduction band states. Information is to be gained from theshape of the particular resonance and by a comparison of the valence band data at excitationenergies off and on resonance. Such studies provide information on the electronic structure, inparticular how to separate individual contributions in the valence band and conduction bandregime.}, language = {en} } @article{Hunger, author = {Hunger, Ralf}, title = {Commissioning of the Solid/Liquid Analysis System SoLiAS}, abstract = {The SoLiAS experimental station is a versatile preparation system dedicated to theinvestigation of solid/liquid interfaces with synchrotron radiation induced photoelectronspectroscopy SPS. During 2002 the system was installed at BESSY and succesfullycommissioned at beamlines TGM 7 and U49/2.}, language = {de} } @incollection{MuellerBaerHenkeletal., author = {M{\"u}ller, Klaus and B{\"a}r, Werner and Henkel, Karsten and Jahnke, Agnes and Schwiertz, Carola and Schmeißer, Dieter}, title = {Organische Feldeffekttransistoren als Transducer in der Biosensorik}, publisher = {w.e.b.-Univ.-Verl.}, address = {Dresden}, isbn = {3-935712-92-8}, pages = {119 -- 223}, language = {de} } @misc{SchmeisserMuessig, author = {Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim}, title = {Stability and electronic properties of silicates in the system SiO2 - Pr2O3 - Si(001)}, series = {Journal of Physics: Condensed Matter}, volume = {16}, journal = {Journal of Physics: Condensed Matter}, number = {2}, issn = {1361-648X}, pages = {153 -- 160}, abstract = {Pr2O3 is one of the most promising hetero-oxides that are the candidates of choice to replace SiO2 as the gate dielectric material for sub-0.1 micrometer CMOS technology. In order to enable process integration, however, hetero-oxides require substantial characterization. In particular, the basic interaction mechanisms at the interface to the silicon substrate are the key issues. A solid knowledge of these mechanisms is required to address reliability arguments. The challenges in material science are to understand the chemical bonding of the hetero-oxides and Si on a microscopic scale. We report on the specific variations in the electronic structure which are evident in the valence band features around resonant excitation at the Pr 4d threshold. We also determine the valance band discontinuities at the Pr2O3/Si(001) interface and follow the changes in the surface potentials to develop a band scheme, a prerequisite to understanding the properties of charge transport across that interface.}, language = {en} } @article{PaloumpaYfantisHoffmannetal., author = {Paloumpa, Ioanna and Yfantis, Alexandros D. and Hoffmann, Patrick and Burkov, Yevgen and Yfantis, Alexandros D. and Schmeißer, Dieter}, title = {Mechanisms to inhibit corrosion of Al alloys by polymeric conversion coatings}, abstract = {We introduce a recently developed novel polypyrrole-based coating, which can be formed on the aluminium surface from an aqueous pyrrole solution of fluorozirconic and fluorotitanic acid neutralised with zinc oxide. The composite layer consists of polypyrrole (Ppy) chemisorbed on titanium and zinc oxides and exhibits advanced corrosion resistance. For the investigation of the structure and the corrosion mechanism of the composite corrosion resistant layer we use a photo-electron emission microscope (PEEM). PEEM is especially suitable because it can deliver topographic contrast as well as elemental contrast and chemical information in connection with a variable X-ray source. Additionally, in order to investigate further the corrosion mechanism, but also the role of the alloy in the corrosion process, we examine the aluminium samples with SEM/EDX. The structure of the corrosion resistant layer was investigated before and after accelerated corrosion tests. Our results pointed out the important role of titanium oxide and zinc in the corrosion resistance of our Ppy coating on aluminium.}, language = {en} } @misc{SchmeisserMuessigDabrowski, author = {Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim and Dabrowski, Jarek Marek}, title = {Silicate Layer Formation at the Pr2O3 / Si(001) Interfaces}, series = {Applied Physics Letters}, volume = {85}, journal = {Applied Physics Letters}, number = {1}, issn = {1077-3118}, pages = {88 -- 90}, abstract = {We studied Pr2O3/Si(001) interfaces by synchrotron radiation photoelectron spectroscopy and by ab initio calculations. We show that the interface formed during molecular-beam epitaxy under the oxygen partial pressure above 1\%D710-8 mbar consists of a mixed Si-Pr oxide, such as (Pr2O3)(SiO)x(SiO2)y. Neither an interfacial SiO2 nor an interfacial silicide is formed. The silicate formation is driven by a low energy of O in a PrOSi bond and by the strain in the subsurface SiOx layer. We expect that this natural interfacial Pr silicate will facilitate the integration of the high-k dielectric Pr2O3 into future complementary metal-oxide-semiconductor technologies.}, language = {en} } @article{Schmeisser, author = {Schmeißer, Dieter}, title = {Covalent and localized contributions of Pr4f states at the interface of Pr2O3 to Si(001)}, abstract = {Resonant photoelectron spectroscopy (PES) at the Pr4d and O1 s absorption edges is used to study the electronic properties at the interface of epitaxially grown Pr2O3 on Si(001).In the electronic structure of bulk Pr2O3, the valence band (VB) states are predominant of Pr6s and O2p atomic parentage. The contribution of Pr4f states is identified from the strong increase of the VB features at the Pr4d resonances. The data at the O1s edge are caused by Raman scattering and resonant Auger decay and reflect the existence of charge transfer (CT) complexes. These complexes are the consequence of a mixed valency caused by ligand-to-Pr4f charge transfer states. The decrease of their intensity is attributed to an increase in covalent bandwidth between the ligand (O2p, Si3p) and Pr4f states. The CT complexes, originally localized now, become broadened and form gap states which fill the gap towards a metallic density of states. The metallic phase may be hindered upon alloying with SiO2 or other oxides.}, language = {en} } @misc{LupinaDabrowskiFormaneketal., author = {Lupina, Grzegorz and Dabrowski, Jarek Marek and Formanek, Peter and Schmeißer, Dieter and Sorge, Roland and Wenger, Christian and Zaumseil, Peter and M{\"u}ssig, Hans-Joachim}, title = {Solid-state reaction between Pr and SiO2 studied by photoelectron spectroscopy and ab initio calculations}, series = {Materials Science in Semiconductor Processing}, volume = {7}, journal = {Materials Science in Semiconductor Processing}, number = {4-6}, issn = {1369-8001}, pages = {215 -- 220}, abstract = {We report on the structural and electrical properties of Pr-based high-k dielectric films fabricated by solid-state reaction between metallic Pr and SiO2 underlayers. A non-destructive depth profiling using synchrotron radiation excited photoelectron spectroscopy (SR-PES), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were employed to examine the chemical composition and microstructure. Ab initio calculations were done to gain insight into the physical processes involved. SR-PES results indicate that Pr deposition at room temperature (RT) leads to the formation of a Pr silicide and a Pr oxide, what is in good agreement with the scenario expected from ab initio calculations. As revealed by TEM and electrical measurements, oxidation of the reacted structures, followed by annealing, results in a stacked dielectric composed of a SiO2-based buffer with an enhanced permittivity and a Pr silicate film with a high dielectric constant. The leakage current density of 10-4 A/cm2 was measured for stacks with capacitance equivalent thickness (CET) of 1.5 nm prepared by evaporation of the Pr layer on a 1.8 nm SiO2 film, followed by oxidation in air ambient and annealing in N2 atmosphere. The capacitance-voltage (C-V) curves exhibit a large flatband voltage (VFB) shift indicating the presence of a positive charge in the stack. Switching away from the Al contacts to Au gate electrodes introduces a significant reduction of the VFB by 1.3 eV, what is much more than the change expected from the work function difference between Al and Au (not, vert, similar0.9 eV). This in turn implies that VFB is strongly affected by the gate interface electrode.}, language = {en} } @misc{YfantisTzalasLambrakopoulosetal., author = {Yfantis, Alexandros D. and Tzalas, B. and Lambrakopoulos, S. and Anagnostaki, E. and Schmeißer, Dieter}, title = {New chrome free, environmentally friendly methods in chemical processes}, abstract = {It gives an overview of the research work to develop chrom-free methods in different chemical processes. A new class of materials, the conductive polymers, have been studied extensively for their anticorrosion properties.}, language = {en} } @misc{LewerenzMurrellJakubowiczetal., author = {Lewerenz, Hans-Joachim and Murrell, Chris and Jakubowicz, J. and Aggour, Mohammed and Kanis, M. and Campbell, S. A. and Cox, P. A. and Hoffmann, Patrick and Jungblut, H. and Schmeißer, Dieter}, title = {High Resolution Surface analysis of Si Roughenning in Dilute Ammonium Fluoride Solution}, series = {Journal of Electroanalytical Chemistry}, volume = {540}, journal = {Journal of Electroanalytical Chemistry}, issn = {1873-2569}, pages = {3 -- 6}, abstract = {The initial stages of porous Si formation on Si(111) in dilute ammonium fluoride solution are analysed by photoelectron spectroscopy using synchrotron radiation (SRPES). The PES results in the por-Si formation regime partly support a recent dissolution model. The contribution from the Si 2p surface core level shift shows that 0.35 ML of the surface is still H-terminated after interruption of the conditioning process at the first photocurrent maximum. Two signals shifted in binding energy by 0.8 and 1 eV, respectively, are attributed to reaction intermediates expected from the proposed reaction mechanism and from theoretical calculations using density functional theory (DFT). A distinct roughening is found in in-situ AFM measurements, with a calculated RMS roughness parameter of 2.6 nm.}, language = {en} } @misc{AppelAdeGuereketal., author = {Appel, G{\"u}nter and Ade, H. and G{\"u}rek, A. G. and Stadler, S. and Mikalo, Ricardo Pablo and Schmeißer, Dieter}, title = {Orientation studies of Si-Phthalocyanines sulfonic acids cast on SiOx substrates}, series = {Applied Physics / A}, volume = {76}, journal = {Applied Physics / A}, number = {2}, issn = {1432-0630}, doi = {10.1007/s003390201320}, pages = {177 -- 182}, abstract = {Layers of dihydroxy silicon phthalocyanine tetrasulfonic acid and oligo-7-oxo silicon phthalocyanine tetrasulfonic acid were prepared by solution-casting methods. The purity of the material was checked by X-ray photoemission spectroscopy. The orientation of the molecules in respect to the substrate plane was investigated by angle-dependent near-edge X-ray absorption fine-structure spectroscopy. The morphology was characterized by atomic force microscopy. Most samples exhibited a significant orientation that was accompanied by crystalline structures; others had no orientation at all with a dominant amorphous morphology. This behavior indicates that several preparation parameters affect the crystallinity and the orientation of the phthalocyanines.}, language = {en} } @phdthesis{Meier, author = {Meier, Ulrich}, title = {Grenzfl{\"a}chenverhalten und Morphologie des ZnO/Si-Heterokontaktes: Eine Photoemissionsstudie}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-000000551}, language = {de} } @article{Burkov, author = {Burkov, Yevgen}, title = {Comparison on Focus-PEEM and Elmitec-PEEM}, language = {en} } @article{Hoffmann, author = {Hoffmann, Patrick}, title = {Photoemission studies of very thin (<10nm) silicon oxynitride (SiOxNy) layers formed by PECVD}, abstract = {The "ITRS Roadmap" suggests the necessity of working out the processing methods allowing formation of ultrathin dielectric layers with higher values of the dielectric permittivity than for silicon dioxide. The silicon oxynitride layers (SiOxNy) seem to be the most natural compromise. But still none of high temperature methods used for its formation can be seriously considered as final solution for future ULSI-CMOS ICs production due to the inevitable formation of nitride monolayers just at the silicon-insulator interface. The main scope of this investigation is to check if this is true.}, language = {en} } @misc{MuellerGoryachkoBurkovetal., author = {M{\"u}ller, Klaus and Goryachko, Andriy and Burkov, Yevgen and Schwiertz, Carola and Ratzke, Markus and K{\"o}ble, J. and Reif, J{\"u}rgen and Schmeißer, Dieter}, title = {Scanning Kelvin Probe Microscopy and Photoemission electron microscopy of organic source-drain structures}, series = {Synthetic Metals}, volume = {146}, journal = {Synthetic Metals}, number = {3}, issn = {0379-6779}, pages = {377 -- 382}, abstract = {n order to optimize organic field effect transistors (OFETs), the characterisation of active-layer surfaces in terms of their roughness, chemical composition and distribution of surface potentials is important. We report on high-resolution microscopic mapping of organic source-drain structures with P3HT as the semiconductor by scanning Kelvin probe microscopy (SKPM) and photoemission electron microscopy (PEEM). It was shown that PEEM is able to characterise the surface morphology (roughness), the chemical homogeneity and the composition of organic structures. The two-dimensional mapping of surface potentials by SKPM with applied source-drain voltages is shown to be an important ingredient of OFETs failure mode analysis.}, language = {en} } @misc{MuessigDabrowskiWengeretal., author = {M{\"u}ssig, Hans-Joachim and Dabrowski, Jarek Marek and Wenger, Christian and Lupina, Grzegorz and Sorge, Roland and Formanek, Peter and Zaumseil, Peter and Schmeißer, Dieter}, title = {Ultrathin Dielectric Films Grown by Solid Phase Reaction of Pr with SiO2}, series = {MRS Proceedings}, volume = {811}, journal = {MRS Proceedings}, issn = {1946-4274}, pages = {D7.10.}, language = {en} } @misc{SchmeisserMuessig, author = {Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim}, title = {Pr4f occupancy and VB/CB band offsets of Pr2O3 at the interface to Si(001) and SiC(0001) surfaces}, series = {MRS Proceedings}, volume = {811}, journal = {MRS Proceedings}, issn = {1946-4274}, pages = {D6.7}, language = {en} } @article{HoffmannSchmeisserSoinski, author = {Hoffmann, Patrick and Schmeißer, Dieter and Soinski, M. S.}, title = {Promieniowanie synchrotronowe jako uniwersalne narzedzie badawcze - Proby jego wykorzystania w badaniach struktury zeliwa}, language = {de} } @misc{YfantisPaloumpaSchmeisser, author = {Yfantis, Alexandros D. and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Corrosion Protection by Conductive Polymers for Magnesium Alloys}, series = {Magnesium, proceedings of the 6th International Conference on Magnesium Alloys and their Applications, November 2003 in Wolfsburg}, journal = {Magnesium, proceedings of the 6th International Conference on Magnesium Alloys and their Applications, November 2003 in Wolfsburg}, editor = {Kainer, Karl Ulrich}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {3-527-30975-6}, pages = {605 -- 610}, abstract = {In this work, we present the experimental data related to the effect of the polypyrrole concentration and the film thickness on the corrosion inhibition properties of these novel polymer coatings. The relative corrosion resistance properties of the films formed from the matrix solutions, where polypyrrole was in situ polymerized and in cases where polypyrrole is dispersed in a form of powder (pigment) in the polyaclylic polymer, are further examined. The evaluation of the experimental data provides significant evidence regarding the mechanism of corrosion inhibition, as well as the optimization of the synthesis and application conditions.}, language = {en} } @inproceedings{SidorenkoTokarevKreneketal., author = {Sidorenko, Alexander and Tokarev, Igor and Krenek, Radim and Burkov, Yevgen and Schmeißer, Dieter and Minko, S. and Stamm, Manfred}, title = {Generation of Nanostructured Materials from Thin Films of Block Copolymer Assembles}, series = {Nano-architectured and manostructured materials, fabrication, control and properties, EUROMAT 2003}, booktitle = {Nano-architectured and manostructured materials, fabrication, control and properties, EUROMAT 2003}, editor = {Champion, Yannick and Fecht, Hans-J{\"o}rg}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {3-527-31008-8}, pages = {143 -- 150}, language = {en} } @misc{TokarevKrenekBurkovetal., author = {Tokarev, Igor and Krenek, Radim and Burkov, Yevgen and Schmeißer, Dieter and Sidorenko, Alexander and Minko, Sergiy and Stamm, Manfred}, title = {Microphase separation in thin films of poly(styrene-block-4-vinylpyridine) Copolymer-2-(4-Hydroxybenzeneazo) benzoic Acid Assembly}, series = {Macromolecules}, volume = {38}, journal = {Macromolecules}, number = {2}, issn = {1520-5835}, pages = {507 -- 516}, abstract = {The fine structure of thin films of poly(styrene-block-4-vinylpyridine) copolymer-2-(4'-hydroxybenzeneazo)benzoic acid (PS-PVP+HABA) assembly has been studied using the combination of atomic force microscopy, ellipsometry, X-ray reflectivity, GISAXS, XPS, and XPEEM. The films consist of cylindrical nanodomains formed by PVP+HABA associates surrounded by PS matrix. Alignment of the domains can be switched upon exposure to vapors of different solvents from the parallel to perpendicular orientation and vice versa with respect to the surface plane. Swelling in 1,4-dioxane leads the system from the cylindrical to the spherical morphology. Solvent evaporation results in a shrinkage of the matrix in the vertical direction and subsequent merging of the spheres into the perpendicularly aligned cylinders. The cylinders form a regular hexagonal lattice with a spatial period of 25.5 nm. On the other hand, vapors of chloroform induce in-plane alignment. The films consist of parallel layers of the cylinders separated by PS matrix and demonstrate the fingerprint-like structure. The nanocylinders of PVP+HABA are packed into a distorted hexagonal lattice exhibiting 31 nm in plane and 17 nm vertical periodicity. In both cases a thin wetting layer is found at the polymer-substrate interface. The free surface is enriched with PS.}, language = {en} } @article{Hoffmann, author = {Hoffmann, Patrick}, title = {Oxynitride on 4H-SiC (0001)}, abstract = {It will be reported on the growth of oxynitride ultra-thin layers (<2 nm) on (0 0 0 1)-oriented 4H-SiC surfaces. The oxynitride layers were grown by a thermal treatment of the samples in low pressure (up to 1000 Pa) N2O ambient. By varying the growth conditions (N2O pressure, sample temperature, growth time) different layers were made. The highest nitrogen incorporation was found to be at high temperatures and low N2O pressures.The grown layers were investigated by photoelectron spectroscopy (XPS) for chemical analysis. Concerning the chemical analysis, the general nitrogen content of the samples is compared at different preparation conditions. The films are found to consist mainly of SiO2 and small fraction of silicon nitride. Only a tenth of the nitrogen was incorporated as oxynitride. The results obtained for oxynitride thin films on 4H-SiC are compared to similarly prepared oxynitride layers on Si(1 1 1) investigated in the past. Furthermore, an additional source of nitrogen due to dopand diffusion in the SiC single crystal is reported.}, language = {en} } @incollection{HenkelSchwiertzWagneretal., author = {Henkel, Karsten and Schwiertz, Carola and Wagner, S. and Valdeig, A. and List, M. and Schmeißer, Dieter}, title = {Partikel- und Tropfendetektion im Mikrometerbereich mittels Schwingquarzen}, publisher = {w.e.b.-Univ.-Verl.}, address = {Dresden}, isbn = {3-935712-92-8}, pages = {291 -- 294}, language = {de} } @misc{LamprakopoulosSchmeisserAnastassopoulouetal., author = {Lamprakopoulos, Stelios and Schmeißer, Dieter and Anastassopoulou, Jane and Theophanides, Theophile and Yfantis, Alexandros D.}, title = {An FTIR study of the role of H2O and D2O in the aging mechanism of conductive polypyrroles}, series = {Synthetic Metals}, volume = {144}, journal = {Synthetic Metals}, number = {3}, issn = {0379-6779}, doi = {10.1016/j.synthmet.2004.03.006}, pages = {229 -- 234}, abstract = {In the present work the role of H2O was studied by conductivity measurements and FTIR spectroscopy using the isotopic effect of deuterium in order to elucidate the aging mechanism of conductivity of polypyrroles. Polypyrrole was prepared with PTS as a dopant, by using deuterated water. Conductivity measurements showed changes due to structural water and atmospheric humidity. The FTIR absorption spectra indicated that the most probable structure of polypyrrole is the two-dimensional one. This finding could be attributed to the inhibition of polypyrrole's IR modes. The infrared spectrum analysis show that the gamma -NH bending mode of pyrrole has significantly changed after polymerization of pyrrole and this result is in accordance with XPS measurements.}, language = {en} } @article{Schmeisser, author = {Schmeißer, Dieter}, title = {Pr2O3/Si(001) interface reactions and stability}, abstract = {We show that an interfacial silicate is formed in a natural way between Si(0 0 1) and the deposited Pr2O3 film if a sufficient amount of oxygen is provided during deposition, as during electron beam evaporation from Pr6O11 source. We provide arguments from results of ab initio calculations and we present a ternary phase diagram of the Pr-O-Si system obtained for epitaxial films from non-destructive depth profiling data acquired by synchrotron radiation and photoelectron spectroscopy (SR-PES) at the undulator beam line U49/2-PGM2. The composition of the interfacial layer is (Pr2O3)(SiO)x(SiO2)y, with x+y between 2 and 6 and depends on the growth condition and distance from the substrate. No interfacial SiO2 and no interfacial silicide is formed during growth. The ternary phase diagram indicates that this non-stoichiometric pseudobinary alloy is stable on Si up to high temperatures, without phase separation into Pr2O3 and SiO2. Therefore, a complete re-engineering of the CMOS process may be not necessary.}, language = {en} } @misc{SidorenkoTokarevKreneketal., author = {Sidorenko, Alexander and Tokarev, Igor and Krenek, Radim and Burkov, Yevgen and Schmeißer, Dieter and Stamm, Manfred}, title = {XPEEM investigations of 2D hierachical array of Ni nanorods using block copolymer templates}, language = {de} } @article{Schmeisser, author = {Schmeißer, Dieter}, title = {Cooper minimum observed for the Pr5s and Pr5p states in Pr2O3}, language = {en} } @article{Hoffmann, author = {Hoffmann, Patrick}, title = {Chemical state depth profiling of ultra-thin oxynitride layers by photoelectron spectroscopy}, language = {en} } @article{Traeger, author = {Traeger, S.}, title = {A PEEM study of lateral inhomogeneities on etched CdTe(110) surfaces}, language = {en} } @incollection{SchmeisserLupinaMuessig, author = {Schmeißer, Dieter and Lupina, Grzegorz and M{\"u}ssig, Hans-Joachim}, title = {High reactivity of Pr on oxide covered 4H-SiC}, series = {Bessy annual report 2003}, booktitle = {Bessy annual report 2003}, publisher = {Bessy}, address = {Berlin}, pages = {408 -- 409}, language = {en} } @article{Mueller, author = {M{\"u}ller, Klaus}, title = {PEEM studies of KCN-etched CuInS2 surfaces}, language = {de} } @article{Schmeisser, author = {Schmeißer, Dieter}, title = {Interface reactivity of Pr and SiO2 at 4H-SiC(0001)}, abstract = {We use photoelectron spectroscopy to characterize the reactivity of Pr evaporated on SiO2 covered 4H-SiC substrates. We analyze the Si2p, C1s, and O1s core levels and find that Pr reacts at RT with the SiO2 layer to form Pr-silicate. In addition also Pr-silizide is formed as well as Pr-carbides. While the latter are formed as reaction intermediates after Pr evaporation, the Pr-silicate layer is formed upon annealing to 300 °C and is stable up to 800 °C.}, language = {en} } @article{Mueller, author = {M{\"u}ller, Klaus}, title = {PEEM imaging contrast in an operating organic electronic device}, language = {en} } @article{Schmeisser, author = {Schmeißer, Dieter}, title = {Pr4f occupancy and origin of gap states at the Pr2O3 / Si (001) interface}, language = {en} } @article{SeifarthBurkovGoryachkoetal., author = {Seifarth, Olaf and Burkov, Yevgen and Goryachko, Andriy and Schmeißer, Dieter and Sydorenko, Alexander and Krenek, Radim and Stamm, Manfred}, title = {Photoelectron spectroscopy and microscopy on Cr nano particels embedded into block copolymers}, language = {en} } @article{Sohal, author = {Sohal, Rakesh}, title = {Pr-Silicate formation on SiO2 covered SiC surfaces}, language = {de} } @article{Torche, author = {Torche, Mohamed}, title = {The interaction of titanium to Pr2O3 thin films dielectrics}, language = {de} } @article{Hoffmann, author = {Hoffmann, Patrick}, title = {Oxynitride Grotwth on 4H-SiC(0001) by N2O}, language = {de} } @article{Mueller, author = {M{\"u}ller, Klaus}, title = {Spectro-Microscopic Characterisation of CuInS2 Surfaces}, abstract = {hotoemission electron microscopy (PEEM) is used to study CuInS2 surfaces. CuInS2 (CIS) is used as polycrystalline absorber layer for thin film solar cells. A characterisation in terms of morphological information, elemental distribution, and of doping inhomogeneities at the surface is very important. We demonstrate that the method is capable for such surface studies in high lateral resolution. The use of synchrotron radiation allows the visualization of chemical inhomogeneities in single grains. By taking PEEM images around the absorption edges of Cu, In, or S, we are able to map elemental distributions, separated from morphology-dependent information in the PEEM image.}, language = {en} } @inproceedings{SchmeisserMuessig, author = {Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim}, title = {Pr-silicate formation on SiO2 covered 3C-SiC(111)}, series = {Physics of semiconductors, 27th International Conference on the Physics of Semiconductors}, booktitle = {Physics of semiconductors, 27th International Conference on the Physics of Semiconductors}, publisher = {AIP, American Inst. of Physics}, address = {New York, NY}, isbn = {0-7354-0257-4}, pages = {75 -- 76}, language = {en} } @article{WehnerSchmeisserHoffmann, author = {Wehner, Stefan and Schmeißer, Dieter and Hoffmann, Patrick}, title = {Spatiotemporal patterns of external noise-induced transitions in a bistable reaction-diffusion system : Photoelectron Emission Microscopy experiments and modeling}, language = {en} } @misc{LupinaSchroederDabrowskietal., author = {Lupina, Grzegorz and Schroeder, Thomas and Dabrowski, Jarek Marek and Schmeißer, Dieter and Hoffmann, Patrick}, title = {Praseodymium silicate layers with atomically abrupt interface on Si(100)}, series = {Applied Physics Letters}, volume = {87}, journal = {Applied Physics Letters}, number = {5}, issn = {0003-6951}, pages = {S. 092901}, language = {en} } @article{GoryachkoYeromenkoHenkeletal., author = {Goryachko, Andriy and Yeromenko, Y. and Henkel, Karsten and Wollweber, J{\"u}rgen and Schmeißer, Dieter}, title = {The Si(001)/C2H2 interaction to form a buffer layer for 3C-SiC growth}, series = {Physica status solidi / A}, volume = {201}, journal = {Physica status solidi / A}, number = {2}, issn = {0031-8965}, pages = {245 -- 248}, abstract = {The intial stages of Si(001) interaction with C2H2 were investigated with XPS and surface profilometry. The carbon enriched layer serves as a buffer between Si substrate and the 3C-SiC film aimed at growing on Si(001). Such parameters as substrate temperature and process duration come into a complicated interplay of C deposition, its reaction with Si and out-diffusion of the later from the substrate. Three distinct regimes, namely graphite dominated, carbide dominated and roughness dominated are found to result from this interplay.}, language = {en} } @article{GoryachkoPaloumpaBeuckertetal., author = {Goryachko, Andriy and Paloumpa, Ioanna and Beuckert, Guido and Burkov, Yevgen and Schmeißer, Dieter}, title = {The Interaction of Pr2O3 with 4H-SiC(0001)surface}, series = {Physica status solidi / C}, volume = {1}, journal = {Physica status solidi / C}, number = {2}, issn = {1610-1634}, pages = {265 -- 268}, abstract = {Praseodymium oxide (Pr2O3) as a hetero-oxide on SiC(0001) represents a promising semiconductor / high-K dielectric material combination. We prepared thin films (<3 nm) of Pr2O3 on 4H-SiC(0001) surfaces by a wet chemical process involving aqueous solutions of Pr(NO3)3. Synchrotron radiation photoelectron spectroscopy (SR-PES) is used to study the chemical composition of these films after deposition and annealing in 300-900 \%B0C range. The Si2p and C1s core level emissions are analysed in detail and reveal that praseodymium-silicate is formed at the interface. Our data are compared to corresponding studies of the Pr2O3 interaction with Si(001) surfaces.}, language = {en} } @misc{MuellerPaloumpaHenkeletal., author = {M{\"u}ller, Klaus and Paloumpa, Ioanna and Henkel, Karsten and Schmeißer, Dieter}, title = {A polymer high-k dielectric insulator for organic field effect Transistors}, series = {Journal of Applied Physics}, volume = {98}, journal = {Journal of Applied Physics}, number = {5}, issn = {0021-8979}, pages = {S. 056104}, language = {en} } @misc{HenkelSohalTorcheetal., author = {Henkel, Karsten and Sohal, Rakesh and Torche, Mohamed and Paloumpa, Ioanna and M{\"u}ller, Klaus and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Grenzfl{\"a}chenoptimierung f{\"u}r funktionale D{\"u}nnschichtsysteme: Oxide und Polymere}, series = {Forum der Forschung}, volume = {9}, journal = {Forum der Forschung}, number = {18}, issn = {0947-6989}, pages = {49 -- 56}, language = {de} } @misc{SchmeisserHimpselDenlingeretal., author = {Schmeißer, Dieter and Himpsel, Franz J. and Denlinger, Jonathan D. and Ederer, David L.}, title = {Resonante Photoemission an der Cu2p Kante von Cu und CuO}, series = {Forum der Forschung}, volume = {9}, journal = {Forum der Forschung}, number = {18}, issn = {0947-6989}, pages = {57 -- 62}, language = {de} } @incollection{SchmeisserHoffmannBeuckert, author = {Schmeißer, Dieter and Hoffmann, Patrick and Beuckert, Guido}, title = {Electronic Properties of the Interface Formed by Pr2o3 Growth on Si(001), Si(111)and SiC(0001) Surfaces}, editor = {Zschech, Ehrenfried and Whelan, Caroline}, language = {en} } @article{MuellerScheerSchmeisseretal., author = {M{\"u}ller, Klaus and Scheer, R. and Schmeißer, Dieter and Burkov, Yevgen}, title = {Preparation of stoichiometric CuInS2-Surfaces}, series = {Thin Solid Films}, volume = {451-452}, journal = {Thin Solid Films}, issn = {0040-6090}, pages = {120 -- 123}, language = {en} } @incollection{ZschechEngelmannOhsiek, author = {Zschech, Ehrenfried and Engelmann, Hans-J{\"u}rgen and Ohsiek, Susanne}, title = {Advanced MOSFET Gate Dielectrics for High-Performance Microprocessors: Materials Selection and Analytical Challenges}, editor = {Kramer, B.}, doi = {http://dx.doi.org/10.1007/11423256_30}, language = {en} } @article{MuellerBurkovSchmeisser, author = {M{\"u}ller, Klaus and Burkov, Yevgen and Schmeißer, Dieter}, title = {Photo-Emission-Electron-Microscopy for Characterization of an Operating Organic Electronic Device}, language = {en} } @misc{HoffmannSchmeisser, author = {Hoffmann, Patrick and Schmeißer, Dieter}, title = {Improvement of Nitrogen Incorporation into Oxynitrides on 4H-SiC(0001)}, series = {Nuclear Instruments and Methods in Physics Research, Section B : Beam with Materials and Atoms}, volume = {246}, journal = {Nuclear Instruments and Methods in Physics Research, Section B : Beam with Materials and Atoms}, number = {1}, pages = {85 -- 89}, language = {en} } @inproceedings{Schmeisser, author = {Schmeißer, Dieter}, title = {Chemical Bonding in Low-k Dielectric Materials for Interconnect Isolation: Characterization using XAS and EELS}, language = {en} } @article{Schmeisser, author = {Schmeißer, Dieter}, title = {The Consequences of anisotropic Diffusion and Noise: PEEM at the CO Oxidation Reaction on Stepped Ir(111) Surfaces}, language = {en} } @phdthesis{Tavakoli, author = {Tavakoli, Mohammad Hossein}, title = {Numerical analysis of seeding process during Czochralski growth of oxide single crystals}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-145}, language = {en} } @phdthesis{Lupina, author = {Lupina, Grzegorz}, title = {Praseodymium Silicate high-k dielectrics on Si(001)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-421}, language = {en} } @article{MuellerPaloumpaSchmeisseretal., author = {M{\"u}ller, Klaus and Paloumpa, Ioanna and Schmeißer, Dieter and Henkel, Karsten}, title = {Organic thin film transistors with polymer high-k dielectric insulator}, language = {en} } @misc{SeifarthSchmeisserStammetal., author = {Seifarth, Olaf and Schmeißer, Dieter and Stamm, Manfred and Krenek, Radim and Sydorenko, Alexander}, title = {Electron spectroscopy and microscopy on chromium oxide nanowires on templated block copolymers}, series = {Progress in Solid State Chemistry}, volume = {34}, journal = {Progress in Solid State Chemistry}, number = {2-4}, issn = {0079-6786}, pages = {111 -- 119}, language = {en} } @inproceedings{HoffmannSchmeisserEngelmannetal., author = {Hoffmann, Patrick and Schmeißer, Dieter and Engelmann, Hans-J{\"u}rgen and Zschech, Ehrenfried and Stegmann, Heiko and Himpsel, Franz J. and Denlinger, Jonathan D.}, title = {Characterization of chemical bonding in low-k dielectric materials for interconnect isolation: A XAS and EELS Study}, series = {Materials, technology and reliability of low-k dielectrics and copper interconnects, symposium held April 18 - 21, 2006, San Francisco, California}, booktitle = {Materials, technology and reliability of low-k dielectrics and copper interconnects, symposium held April 18 - 21, 2006, San Francisco, California}, editor = {Tsui, Ting Y.}, publisher = {Materials Research Society}, address = {Warrendale, Pa.}, isbn = {978-1-55899-870-5}, pages = {55 -- 62}, language = {en} } @inproceedings{SchmeisserZhengPerezDieste, author = {Schmeißer, Dieter and Zheng, Fan and Perez-Dieste, Virginia}, title = {Silicate Formation at the Interface of Pr-Oxide as a High-K Dielectric and Si(001) surfaces}, language = {en} } @inproceedings{DomaradzkiSchmeisserKaczmareketal., author = {Domaradzki, Jarosław and Schmeißer, Dieter and Kaczmarek, Danuta and Beuckert, Guido and Prociow, E. L. and Borkowska, Angnieszka and Kudrawiec, Robert and Misiewicz, J.}, title = {Characterization of Nanocrystalline TiO2 - HfO2 Thin Films Prepared by Low Pressure Hot Target Reactive Magnetron Sputtering}, language = {en} } @article{DomaradzkiKaczmarekSchmeisseretal., author = {Domaradzki, Jarosław and Kaczmarek, Danuta and Schmeißer, Dieter and Beuckert, Guido}, title = {Microstructure and Optical Properties of TiO2 Thin Films Prepared by Low Pressure Hot Target Reactive Magnetron Sputtering}, language = {en} } @inproceedings{SchmeisserZhengHimpseletal., author = {Schmeißer, Dieter and Zheng, Fan and Himpsel, Franz J. and Engelmann, Hans-J{\"u}rgen and Zschech, Ehrenfried}, title = {Silicate Formation at the Interface of High-k Dielectrics and Si(001) Surfaces}, language = {en} } @inproceedings{ZschechStegmannSchmeisseretal., author = {Zschech, Ehrenfried and Stegmann, Heiko and Schmeißer, Dieter and Hoffmann, Patrick}, title = {Chemical Bonding, Permittivity, and Elastic Properties in Locally Modified Organosilicate Glass}, language = {en} } @article{HoffmannWehnerSchmeisser, author = {Hoffmann, Patrick and Wehner, Stefan and Schmeißer, Dieter}, title = {Noise-Induced Spatiotemporal Patterns in a Bistable Reaction-Diffusion System: Photoelectron Emission Microscopy experiments and Modeling of the CO Oxidation Reaction on Ir(111)}, language = {en} } @article{SchmittBiermanSchmeisseretal., author = {Schmitt, Andrew L. and Bierman, Matthew J. and Schmeißer, Dieter and Himpsel, Franz J. and Jin, Song}, title = {Synthesis and Properties of Single-Crystal FeSi Nanowires}, language = {en} } @article{SchmittZhuSchmeisseretal., author = {Schmitt, Andrew L. and Zhu, Lei and Schmeißer, Dieter and Himpsel, Franz J. and Jin, Song}, title = {Metallic Single-Crystal CoSi Nanowires via Chemical Vapor Deposition of Single-Source Precursor}, language = {en} } @article{LupinaSchroederSchmeisseretal., author = {Lupina, Grzegorz and Schroeder, Thomas and Schmeißer, Dieter and Dabrowski, Jarek Marek}, title = {Praseodymium Silicate Films on Si(100) for Gate Dielectric Applications: Physical and Electrical Characterization}, language = {en} } @inproceedings{TallaridaSchmeisserZheng, author = {Tallarida, Massimo and Schmeißer, Dieter and Zheng, Fan}, title = {X-ray Absorption and Photoemission Spectroscopy of 3C- and 4H-SiC}, language = {en} } @inproceedings{TallaridaSohalSchmeisser, author = {Tallarida, Massimo and Sohal, Rakesh and Schmeißer, Dieter}, title = {Resonant photoemission at the oxygen K edge as a tool to study the electronic properties of defects at SiO2/Si and SiO2/SiC interfaces}, language = {en} } @article{SchmeisserZschech, author = {Schmeißer, Dieter and Zschech, Ehrenfried}, title = {Silicate Formation at the Interface of Hf-Oxide and Pr-Oxide as a High-k Dielectric and Si(001) surfaces}, language = {en} } @inproceedings{SohalTorcheSchmeisser, author = {Sohal, Rakesh and Torche, Mohamed and Schmeißer, Dieter}, title = {Al-Oxynitrides as a Buffer Layer for Pr2O3/SiC Interfaces}, language = {en} } @article{TorcheHenkelSchmeisser, author = {Torche, Mohamed and Henkel, Karsten and Schmeißer, Dieter}, title = {The interaction of Al, Ag, Au and Ti to Pr2O3 thin film dielectrics}, language = {en} } @misc{SeifarthBurkovSchmeisseretal., author = {Seifarth, Olaf and Burkov, Yevgen and Schmeißer, Dieter and Stamm, Manfred}, title = {Metallic nickel nanorod arrays embedded into ordered block copolymer templates}, series = {Thin Solid Films}, volume = {515}, journal = {Thin Solid Films}, number = {16}, issn = {0040-6090}, pages = {6552 -- 6556}, language = {en} } @misc{SchroederLupinaSeifarthetal., author = {Schroeder, Thomas and Lupina, Grzegorz and Seifarth, Olaf and Tallarida, Massimo and Schmeißer, Dieter}, title = {Synchrotron radiation x-ray photoelectron spectroscopy study on the interface chemistry of high-k PrxAl2-xO3 (x=0-2) dielectrics on TiN for dynamic random access memory applications}, series = {Journal of Applied Physics}, volume = {102}, journal = {Journal of Applied Physics}, number = {1}, issn = {0021-8979}, pages = {014103}, language = {en} } @article{HenkelSohalSchmeisseretal., author = {Henkel, Karsten and Sohal, Rakesh and Schmeißer, Dieter and Schwiertz, Carola and Burkov, Yevgen and Torche, Mohamed}, title = {Al-oxynitride buffer layer facilities for PrOx/SiC interfaces}, language = {en} } @article{MuellerHenkelSchmeisser, author = {M{\"u}ller, Klaus and Henkel, Karsten and Schmeißer, Dieter}, title = {Organic field effect transistors with ferroelectric hysteresis}, language = {en} } @article{MuellerMandalSchmeisser, author = {M{\"u}ller, Klaus and Mandal, Dipankar and Schmeißer, Dieter}, title = {No interfacial layer for PEDOT electrodes on PVDF: Characterization of reactions at the interface P(VDF/TrFE)/Al and P(VDF/TrFE)/PEDOT:PSS}, language = {en} } @phdthesis{Meyer, author = {Meyer, Moritz Andreas}, title = {Effects of advanced process approaches on electromigration degradation of Cu on-chip interconnects}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-3509}, language = {en} } @phdthesis{Sohal, author = {Sohal, Rakesh}, title = {CVD growth of (001) and (111) 3C-SiC epilayers and their interface reactivity with praseodymium oxide dielectric layers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-121}, language = {en} } @article{SchmeisserBierman, author = {Schmeißer, Dieter and Bierman, Matthew J.}, title = {Ferromagnetic Semiconducting EuO Nanorods}, language = {en} } @inproceedings{SchmeisserWehnerHoffmannetal., author = {Schmeißer, Dieter and Wehner, Stefan and Hoffmann, Patrick and Brand, Helmut R. and K{\"u}ppers, J{\"u}rgen}, title = {Influence of the Substrate on the Pattern Formation of a Surface Reaction}, series = {Nonequilibrium statistical mechanics and nonlinear physics, XV Conference on Nonequilibrium Statistical Mechanics and Nonlinear Physics, Mar del Plata, Argentina, 4 - 8 December 2006}, booktitle = {Nonequilibrium statistical mechanics and nonlinear physics, XV Conference on Nonequilibrium Statistical Mechanics and Nonlinear Physics, Mar del Plata, Argentina, 4 - 8 December 2006}, editor = {Descalzi, Orazio}, publisher = {AIP Publishing}, address = {Melville, New York}, isbn = {978-0-7354-0421-2}, pages = {121 -- 126}, language = {en} } @article{MuellerSeiboldSchmeisser, author = {M{\"u}ller, Sebastian and Seibold, G{\"o}tz and Schmeißer, Dieter}, title = {Preparation and Characterization of TiO2 Thin Films and Cr and Co Doped TiO2 Thin Films}, editor = {Vierhaus, Heinrich Theodor}, language = {en} } @article{Burkov, author = {Burkov, Yevgen}, title = {Dielectric Buffer Layer (Aluminium Oxynitride/AlON) for Ultrathin High-k Materials}, editor = {Vierhaus, Heinrich Theodor}, language = {en} } @misc{TallaridaSchmeisser, author = {Tallarida, Massimo and Schmeißer, Dieter}, title = {Study of Bulk and Interface Defects in Silicon Oxide with X-ray Absorption Spectroscopy}, series = {Materials Science and Engineering : B}, volume = {144}, journal = {Materials Science and Engineering : B}, number = {1-3}, issn = {0921-5107}, pages = {23 -- 26}, language = {en} } @article{BeckHoffmannSchmeisseretal., author = {Beck, Romuald B. and Hoffmann, Patrick and Schmeißer, Dieter and Bieniek, Tomasz and Jakubowski, Andrzej}, title = {Composition and Electrical Properties of Ultra-Thin SiOxNy Layers Formed by rf Plasma Nitrogen Implantation/Plasma Oxidation Processes}, language = {en} } @article{MroczynskiHoffmannSchmeisser, author = {Mroczynski, Robert and Hoffmann, Patrick and Schmeißer, Dieter}, title = {The Influence of Annealing (900 Grad C) of Ultra-Thin PECVD Silicon Oxynitride Layers}, language = {en} } @article{SchmeisserMroczynskiBieniek, author = {Schmeißer, Dieter and Mroczynski, Robert and Bieniek, Tomasz}, title = {Comparison of Composition of Ultra-Thin Silicon Oxynitride Layers´ fabricated by PECVD and Ultrashallow rf Plasma Ion Implantation}, language = {en} } @article{SchmeisserBurkovPaloumpaetal., author = {Schmeißer, Dieter and Burkov, Yevgen and Paloumpa, Ioanna and Mandal, Dipankar and Henkel, Karsten}, title = {Microscopic and Spectroscopic Characterization of Interfaces and Dielectric Layers for OFET Devices}, language = {en} } @article{SchmeisserHenkelKaravaev, author = {Schmeißer, Dieter and Henkel, Karsten and Karavaev, Konstantin}, title = {Al-Oxynitride Interfacial Layer Investigations for PrxOy on SiC and Si}, language = {en} } @article{SchmeisserDomaradzkiKaczmareketal., author = {Schmeißer, Dieter and Domaradzki, Jarosław and Kaczmarek, Danuta and Borkowska, Angnieszka and M{\"u}ller, Sebastian}, title = {Influence of Annealing on the Structure and Stoichiometry of Europium-Doped Titanium Dioxide Thin Films}, language = {en} } @phdthesis{Lehmann, author = {Lehmann, Carsten}, title = {Elektronische Struktur d{\"u}nner Halbleiterfilme (Chalkopyrite) als Absorbermaterialien f{\"u}r D{\"u}nnschichtsolarzellen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-4319}, language = {de} } @phdthesis{Mandal, author = {Mandal, Dipankar}, title = {Ultra-thin films of a ferroelectric copolymer: P(VDF-TrFE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-5628}, language = {en} } @misc{SchmeisserMuellerSeifarthetal., author = {Schmeißer, Dieter and M{\"u}ller, S. and Seifarth, Olaf and Dabrowski, Jarek Marek and M{\"u}ssig, Hans-Joachim and Schroeder, Thomas}, title = {On the band gaps and electronic structure of thin single crystalline praseodymium oxide layers on Si(111)}, series = {Journal of vacuum science \& technology / B}, volume = {27}, journal = {Journal of vacuum science \& technology / B}, number = {1}, pages = {271 -- 276}, language = {en} } @phdthesis{Neubauer, author = {Neubauer, Antje}, title = {Untersuchung der ultraschnellen Elektronentransferdynamik an organisch/anorganischen Grenzfl{\"a}chen unter Einsatz von Femtosekundenspektroskopie im Ultrahochvakuum}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-7858}, language = {de} } @misc{HenkelTorcheSohaletal., author = {Henkel, Karsten and Torche, Mohamed and Sohal, Rakesh and Karavaev, Konstantin and Burkov, Yevgen and Schwiertz, Carola and Schmeißer, Dieter}, title = {Pr-O-Al-N dielectrics for metal insulator semiconductor stacks}, language = {en} } @misc{MuellerHenkelMandaletal., author = {M{\"u}ller, Klaus and Henkel, Karsten and Mandal, Dipankar and Seime, Bernd and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Spin coated organic ferroelectric films for non volatile memories}, language = {en} } @misc{KovalLazarevaMuelleretal., author = {Koval, Yuri and Lazareva, I. and M{\"u}ller, P. and M{\"u}ller, Klaus and Henkel, Karsten and Friedrich, Daniel}, title = {Field effect transistors on graphitized polymer surfaces}, language = {en} } @misc{SeifarthSchubertGiussanietal., author = {Seifarth, Olaf and Schubert, Markus Andreas and Giussani, A. and Klenov, D. O. and Schmeißer, Dieter and Schroeder, Thomas}, title = {Single crystalline Pr2-xYxO3 (x=0-2)dielectrics on Si with tailored electronic and crystallographic structure}, volume = {108}, number = {10}, issn = {1089-7550}, pages = {103709}, language = {en} } @misc{MandalHenkelMuelleretal., author = {Mandal, Dipankar and Henkel, Karsten and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Band gab determination of P(VDF-TrFE) copolymer film by electron energy loss spectroscopy}, language = {en} } @misc{SionckeLinBrammertzetal., author = {Sioncke, Sonja and Lin, Hang-Chu and Brammertz, Guy and Delabie, Annelies and Conard, Thierry and Franquet, Alexis and Caymax, Matty and Meuris, Marc and Schmeißer, Dieter and Tallarida, Massimo}, title = {ALD on high mobility channels: engineering the proper gate stack passivation}, series = {ECS Transactions}, volume = {33}, journal = {ECS Transactions}, number = {2}, issn = {1938-5862}, pages = {9 -- 23}, language = {en} } @misc{KolanekHermannDudeketal., author = {Kolanek, Krzysztof and Hermann, Peter and Dudek, Piotr T. and Gotszalk, Teodor and Chumakov, Dmytro and Weisheit, Martin and Hecker, Michael and Zschech, Ehrenfried}, title = {Local anodic oxidation by atomic force microscopy for nano-Raman strain measurements on silicon-germanium thin films}, series = {Thin Solid Films}, volume = {518}, journal = {Thin Solid Films}, number = {12}, issn = {0040-6090}, pages = {3267 -- 3272}, language = {en} } @misc{TammKemellKozlovaetal., author = {Tamm, Aile and Kemell, Marianna and Kozlova, Jekaterina and Sajavaara, Timo and Tallarida, Massimo and Kukli, Kaupo and Sammelselg, V. and Ritala, Mikko and Leskel{\"a}, Markku}, title = {Atomic Layer Deposition and Characterization of Erbium Oxide-Doped Zirconium Oxid Thin Films}, series = {Journal of The Electrochemical Society}, volume = {157}, journal = {Journal of The Electrochemical Society}, number = {10}, pages = {G193 -- G201}, language = {en} } @misc{KukliAarikAidlaetal., author = {Kukli, Kaupo and Aarik, Jaan and Aidla, Aleks and Uustare, Teet and J{\~o}gi, Indrek and Lu, Jun and Tallarida, Massimo and Kemell, Marianna and Kiisler, Alma- Asta and Ritala, Mikko and Leskel{\"a}, Markku}, title = {Structure and morphology of Ru films grown by atomic layer deposition from 1-ethyl-1´-methyl-ruthenocene}, series = {Journal of Crystal Growth}, volume = {312}, journal = {Journal of Crystal Growth}, number = {12-13}, issn = {0022-0248}, doi = {10.1016/j.jcrysgro.2010.03.033}, pages = {2025 -- 2032}, language = {en} } @misc{KolanekTallaridaKaravaevetal., author = {Kolanek, Krzysztof and Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {In situ studies of the atomic layer deposition of thin HfO2 dielectrics by ultra high vacuum atomic force microscope}, language = {en} } @misc{HoZschechSchmeisseretal., author = {Ho, Paul S. and Zschech, Ehrenfried and Schmeißer, Dieter and Meyer, Moritz Andreas and Huebner, Rene and Hauschildt, Meike and Zhang, Lijuan and Gall, Martin and Kraatz, Matthias}, title = {Scaling effects on microstructure and reliability for cu interconnects}, language = {en} } @misc{WehnerKarpitschkaBurkovetal., author = {Wehner, Stefan and Karpitschka, Stefan and Burkov, Yevgen and Schmeißer, Dieter and K{\"u}ppers, J{\"u}rgen and Brand, Helmut R.}, title = {Stochastic aspects of pattern formation during the catalytic oxidation of CO on Pd(111)}, language = {en} } @misc{HenkelSeimePaloumpaetal., author = {Henkel, Karsten and Seime, Bernd and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Buffer layer incestigaions on MFIS capacitors consisting of ferroelectric poly[vinylidene fluoride trifluoroethylene]}, series = {IOP conference series : Materials Science and Engineering}, volume = {8}, journal = {IOP conference series : Materials Science and Engineering}, number = {1}, issn = {1757-899X}, pages = {012036}, language = {en} } @misc{SchmeisserHenkelBergholzetal., author = {Schmeißer, Dieter and Henkel, Karsten and Bergholz, Matthias and Tallarida, Massimo}, title = {The band gab and band offset in ultrathin oxide-semiconductor heterostructures}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Synchrotron radiation spectroscopy studies of ultrathin chromium films on titanium dioxide}, series = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, booktitle = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-4303-1}, pages = {64 -- 68}, language = {en} } @inproceedings{KolanekTallaridaKaravaevetal., author = {Kolanek, Krzysztof and Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {In situ measurements of the atomic layer deposition of high-k dielectrics by atomic force microscope for advanced microsystems}, series = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, booktitle = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-4303-1}, pages = {47 -- 51}, language = {en} } @inproceedings{KlocekFriedrichSchmeisseretal., author = {Klocek, Jolanta and Friedrich, Daniel and Schmeißer, Dieter and Hecker, Michael and Zschech, Ehrenfried}, title = {The stability of C60 and its derivatives upon handling in microsystems technologies}, series = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, booktitle = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-4303-1}, pages = {43 -- 46}, language = {en} } @inproceedings{TallaridaKaravaevKolaneketal., author = {Tallarida, Massimo and Karavaev, Konstantin and Kolanek, Krzysztof and Schmeißer, Dieter}, title = {Nobel "in-situ2" Approach to Modified ALD Processes for Nano-functional Metals Oxide Films}, language = {en} } @incollection{SchwiertzHenkelBleietal., author = {Schwiertz, Carola and Henkel, Karsten and Blei, S. and Heidenreich, R. and Schmeißer, Dieter}, title = {Nachweis von Aerosolen (<1µm) mit Schwingquarzimpedanzspektroskopie}, language = {de} } @misc{ZschechHoSchmeisseretal., author = {Zschech, Ehrenfried and Ho, O. S. and Schmeißer, Dieter and Meyer, Moritz Andreas and Vairagar, A. V. and Schneider, G. and Hauschildt, Meike and Kraatz, Matthias and Sukharev, V.}, title = {Geometry and Microstructure Effect on EM-Induced Copper Interconnect Degradation}, series = {IEEE Transactions on Device and Materials Reliability}, volume = {9}, journal = {IEEE Transactions on Device and Materials Reliability}, number = {1}, issn = {1530-4388}, pages = {20 -- 30}, language = {en} } @inproceedings{HeimFriedrichGuttmannetal., author = {Heim, S. and Friedrich, Daniel and Guttmann, P. and Rehbein, S. and Chumakov, Dmytro and Ritz, Y. and Schneider, G. and Schmeißer, Dieter and Zschech, Ehrenfried}, title = {Dynamical X-ray Microscopy Study of Stress-Induced Voiding in Cu Interconnects}, language = {en} } @misc{SchmeisserHenkelMuelleretal., author = {Schmeißer, Dieter and Henkel, Karsten and M{\"u}ller, Klaus and Tallarida, Massimo}, title = {Interface Reactions in Ultrathin Functional Dielectric Films}, language = {en} } @misc{SchmeisserTallaridaHenkeletal., author = {Schmeißer, Dieter and Tallarida, Massimo and Henkel, Karsten and M{\"u}ller, Klaus and Mandal, Dipankar and Chumakov, Dmytro and Zschech, Ehrenfried}, title = {Characterization of oxidic and organic materials with synchrotron radiation based XPS and XAS}, language = {en} } @misc{LazarevaKovalMuelleretal., author = {Lazareva, I. and Koval, Yuri and M{\"u}ller, P. and M{\"u}ller, Klaus and Henkel, Karsten and Schmeißer, Dieter}, title = {Interface screening and imprint in pol(vinylidene fluoride/trifluoroethylene) ferroelectric field effect transistors}, language = {en} } @incollection{MuellerBurkovMandaletal., author = {M{\"u}ller, Klaus and Burkov, Yevgen and Mandal, Dipankar and Henkel, Karsten and Paloumpa, Ioanna and Goryachko, Andriy and Schmeißer, Dieter}, title = {Microscopic and spectroscopic characterization of interfaces and dielectric layers for OFET devices}, series = {Organic Electronics : structural and Electronic Properties of OFETs}, booktitle = {Organic Electronics : structural and Electronic Properties of OFETs}, editor = {W{\"o}ll, Christof}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {978-3-527-40810-8}, pages = {445 -- 468}, language = {en} } @misc{TallaridaKaravaevSchmeisser, author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {HfO2/Si interface formation in atomic layer deposition films: an in situ investigation}, language = {en} } @misc{HenkelLazarevaMandaletal., author = {Henkel, Karsten and Lazareva, I. and Mandal, Dipankar and Paloumpa, Ioanna and M{\"u}ller, Klaus and Koval, Yuri and M{\"u}ller, P. and Schmeißer, Dieter}, title = {Electrical investigations on metal/ferroelectric/insulator/semiconductor structures using Poly[vinylidene fluoride trifluoroethylene] as ferroelectric layer for organic nonvolatile memory applications}, language = {en} } @misc{HenkelBurkovKaravaevetal., author = {Henkel, Karsten and Burkov, Yevgen and Karavaev, Konstantin and Torche, Mohamed and Schwiertz, Carola and Schmeißer, Dieter}, title = {Optimization of the AION buffer layer for PrxOy/Si stacks}, language = {de} } @article{BieniekBeckJakubowskietal., author = {Bieniek, Tomasz and Beck, Romuald B. and Jakubowski, Andrzej and Konarski, Piotr and Cwil, M. and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Application of r.f. plasma ultrashallow nitrogen ion implantation for pedestal oxynitride layer formation}, language = {en} } @misc{ZschechGeislerRinderknechtetal., author = {Zschech, Ehrenfried and Geisler, Holm and Rinderknecht, Jochen and Schneider, Gerd and Spolenak, Ralph and Schmeißer, Dieter}, title = {Nano-scale analysis using synchrotron-radiation: Applications in the semiconductor industry}, series = {Current nanoscience}, volume = {4}, journal = {Current nanoscience}, number = {3}, issn = {1573-4137}, pages = {256 -- 266}, language = {en} } @misc{ZagorodniyChumakovTaeschneretal., author = {Zagorodniy, Kostyantyn and Chumakov, Dmytro and T{\"a}schner, Christine and Lukowiak, Anna and Stegmann, Heiko and Schmeißer, Dieter and Geisler, Holm and Engelmann, Hans-J{\"u}rgen and Hermann, Helmut and Zschech, Ehrenfried}, title = {Novel Carbon-cage based ultralow-k materials: Modelling and first experiments}, doi = {10.1109/TSM.2008.2005396}, language = {en} } @article{TallaridaSchmeisser, author = {Tallarida, Massimo and Schmeißer, Dieter}, title = {Study of silicon/oxides interfaces by means of Si2p resonant photoemission}, language = {en} } @article{TallaridaKaravaevSchmeisser, author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {The initial atomic layer deposition of HfO2/Si(001) as followed in situ by synchrotron radiation photoelectron spectroscopy}, language = {en} } @article{MuellerMandalHenkeletal., author = {M{\"u}ller, Klaus and Mandal, Dipankar and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Ferroelectric properties of spin-coated ultrathin (down to 10nm) copolymer films}, language = {en} } @misc{OpelNielsenBaueretal., author = {Opel, Matthias and Nielsen, Karl-Wilhelm and Bauer, Sebastian and Goennenwein, Sebastian T. B. and Gross, Rudolf and Cezar, Julio C. and Schmeißer, Dieter and Simon, J{\"u}rgen and Mader, Werner}, title = {Nanosized superparamagnetic precipitates in cobalt-doped ZnO}, series = {The European Physical Journal : B}, volume = {63}, journal = {The European Physical Journal : B}, number = {4}, issn = {1434-6036}, pages = {437 -- 444}, language = {en} } @inproceedings{SeifarthWilkeWalczyketal., author = {Seifarth, Olaf and Wilke, A. and Walczyk, Christian and Dabrowski, Jarek Marek and Zaumseil, Peter and Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim and Schroeder, Thomas}, title = {Band gap and electronic structure determination with XAS and UPS of thin Pr-oxide films on Si(111)}, series = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, booktitle = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, pages = {285 -- 286}, language = {en} } @inproceedings{HenkelBurkovBergholzetal., author = {Henkel, Karsten and Burkov, Yevgen and Bergholz, Matthias and Karavaev, Konstantin and Sohal, Rakesh and Torche, Mohamed and Schmeißer, Dieter}, title = {Al-Oxynitride as a buffer layer for high-k dielectrics}, series = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, booktitle = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, pages = {161 -- 162}, language = {en} } @inproceedings{HenkelMandalSeimeetal., author = {Henkel, Karsten and Mandal, Dipankar and Seime, Bernd and Paloumpa, Ioanna and Lazareva, I. and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Electrical investigations on MFIS structures consisting P[VDF/TrFE] as ferro-electric layer for non-volatile memory applications}, series = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, booktitle = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, pages = {159 -- 160}, language = {en} } @article{ZiminaBatchelorEisebittetal., author = {Zimina, A. and Batchelor, David R. and Eisebitt, S. and Schmeißer, Dieter and Shukalov, A. and Eberhardt, W.}, title = {Soft X-ray emission electron microscopy: chemical state microscopy from interface and bulk}, language = {en} } @article{SchmeisserSeiboldReif, author = {Schmeißer, Dieter and Seibold, G{\"o}tz and Reif, J{\"u}rgen}, title = {Nano-scaled Dielectric Barriers (NanoDieB) for CMOS compatible Si-technologies}, series = {Forum der Forschung}, journal = {Forum der Forschung}, number = {19}, issn = {0947-6989}, pages = {131 -- 136}, language = {en} } @article{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Properties of Cr deposited on TiO2 thin films}, language = {en} } @article{SohalLupinaLippertetal., author = {Sohal, Rakesh and Lupina, Grzegorz and Lippert, Gunther and Wenger, Christian and Seifarth, Olaf and Schr{\"o}der, Thomas and Tallarida, Massimo and Schmeißer, Dieter}, title = {Interface chemistry of high-k PrxAl2-xO3 (x=2-0) dielectrics on TiN for dynamic random access memory applications}, language = {en} } @inproceedings{TallaridaKaravaevSchmeisseretal., author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter and Zschech, Ehrenfried}, title = {HfO2 ALD-growth studied by in situ photoemission}, series = {Proceedings of 15th Workshop on Dielectrics in Micoelectronics, Bad Saarow, 23 - 25 June 2008}, booktitle = {Proceedings of 15th Workshop on Dielectrics in Micoelectronics, Bad Saarow, 23 - 25 June 2008}, pages = {289 -- 290}, language = {en} } @misc{TallaridaAdelmannDelabieetal., author = {Tallarida, Massimo and Adelmann, Christoph and Delabie, Annelies and Elshocht, Sven van and Caymax, Matty and Schmeißer, Dieter}, title = {Surface chemistry and Fermi level movement during the self-cleaning of GaAs by trimethyl-aluminum}, series = {Applied physics letters}, volume = {99}, journal = {Applied physics letters}, number = {4}, issn = {1077-3118}, doi = {10.1063/1.3615784}, pages = {042906-1 -- 042906-3}, language = {en} } @misc{SchwarzkopfDirsyteDevietal., author = {Schwarzkopf, Jutta and Dirsyte, R. and Devi, A. and Kwasniewski, A. and Schmidbauer, M. and Wagner, Gerd and Michling, Marcel and Schmeißer, Dieter and Fornari, Robert}, title = {Influence of Na on the structure of Bi4Ti3O12 films deposited by liquid-delivery spin MOCVD}, series = {Thin solid films}, volume = {519}, journal = {Thin solid films}, number = {17}, issn = {0040-6090}, pages = {5754 -- 5759}, language = {en} } @misc{TallaridaWeisheitKolaneketal., author = {Tallarida, Massimo and Weisheit, Martin and Kolanek, Krzysztof and Michling, Marcel and Engelmann, Hans-J{\"u}rgen and Schmeißer, Dieter}, title = {Atomic layer deposition of nanolaminate oxide films on Si}, series = {Journal of Nanoparticle Research}, volume = {13}, journal = {Journal of Nanoparticle Research}, number = {11}, doi = {10.1007/s11051-011-0319-x}, pages = {5975 -- 5983}, language = {en} } @inproceedings{WyrodekTallaridaWeisheitetal., author = {Wyrodek, Jakub and Tallarida, Massimo and Weisheit, Martin and Schmeißer, Dieter}, title = {Determination of interfacial layers in high-k nanomaterials by ADXPS measurements}, language = {en} } @inproceedings{StarzykTallaridaSchmeisser, author = {Starzyk, Łukasz and Tallarida, Massimo and Schmeißer, Dieter}, title = {Band alignment of high-k/SiO2/Si stacks incorporating Zr and Al oxides prepared by atomic layer deposition}, language = {en} } @misc{SchmeisserSchmidtSeiboldetal., author = {Schmeißer, Dieter and Schmidt, Stephan and Seibold, G{\"o}tz and Cherkashinin, Gennady and Jaegermann, Wolfram}, title = {Localized Gap States in LiCoO2 and their Influence on the Transport Properties in Li-Ion Batteries}, series = {ECS Transactions}, volume = {25}, journal = {ECS Transactions}, number = {35}, issn = {1938-5862}, pages = {37 -- 45}, language = {en} } @misc{KolanekTallaridaSchmeisser, author = {Kolanek, Krzysztof and Tallarida, Massimo and Schmeißer, Dieter}, title = {Atomic layer deposition of HfO2 investigated in situ by means of a noncontact atomic force microscopy}, language = {en} } @inproceedings{BroczkowskaKlocekFriedrichetal., author = {Broczkowska, K. and Klocek, Jolanta and Friedrich, Daniel and Henkel, Karsten and Kolanek, Krzysztof and Urbanowicz, A. and Schmeißer, Dieter and Miller, M. and Zschech, Ehrenfried}, title = {Fullerene based materials for ultra-low-k application}, series = {International Students and Young Scientists Workshop "Photonics and Microsystems", Szklarska, Poreba, Poland, 25 - 27 June 2010}, booktitle = {International Students and Young Scientists Workshop "Photonics and Microsystems", Szklarska, Poreba, Poland, 25 - 27 June 2010}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-8324-2}, pages = {39 -- 43}, language = {en} } @misc{HenkelSeimePaloumpaetal., author = {Henkel, Karsten and Seime, Bernd and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Optimization of MFIS structures containing poly(vinylidene-fluoride trifluoroethylene) for non-volatile memory applications}, language = {en} } @misc{HenkelSeimePaloumpaetal., author = {Henkel, Karsten and Seime, Bernd and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Buffer layer investigations on MFIS capacitors consisting of ferroelectric poly[vinylidene fluoride trifluoroethylene]}, language = {en} } @misc{DudekLupinaKozłowskietal., author = {Dudek, Piotr T. and Lupina, Grzegorz and Kozłowski, Grzegorz and Zaumseil, Peter and Bauer, Jakob and Fursenko, Oksana and Dabrowski, Jarek Marek and Schmidt, R. and Lippert, Gunther and M{\"u}ssig, Hans-Joachim and Schr{\"o}der, Thomas and Schmeißer, Dieter and Zschech, Ehrenfried}, title = {Atomic-scale engineering of future high-k dynamic random access memory dielectrics: The example of partial Hf substitution by Ti in BaHfO3}, series = {Journal of Vacuum Science and Technology / B}, volume = {29}, journal = {Journal of Vacuum Science and Technology / B}, number = {1}, issn = {2166-2754}, language = {en} } @misc{JanowitzSchererMohamedetal., author = {Janowitz, Christoph and Scherer, Valentina and Mohamed, Mansour and Krapf, Alica and Dwelk, Helmut and Manzke, Recardo and Galazka, Zbigniew and Uecker, Reinhard and Irmscher, Klaus and Fornari, Robert and Michling, Marcel and Schmeißer, Dieter}, title = {Experimental electronic structure of In2O3 and Ga2O3}, series = {New Journal of Physics}, volume = {13}, journal = {New Journal of Physics}, number = {8}, issn = {1367-2630}, pages = {085014}, language = {en} } @misc{MandalHenkelSchmeisser, author = {Mandal, Dipankar and Henkel, Karsten and Schmeißer, Dieter}, title = {Comment on "Preparation and Characterization of Silver-Poly(vinylidene fluoride) Nanocomposites:Formation of Piezoelectric Polymorph of Poly(vinylidene fluoride"}, language = {en} } @misc{KolanekTallaridaMichlingetal., author = {Kolanek, Krzysztof and Tallarida, Massimo and Michling, Marcel and Karavaev, Konstantin and Schmeißer, Dieter}, title = {Atomic layer deposition reactor for fabrication of metal oxides}, language = {en} } @misc{TallaridaKukliMichlingetal., author = {Tallarida, Massimo and Kukli, Kaupo and Michling, Marcel and Ritala, Mikko and Leskel{\"a}, Markku and Schmeißer, Dieter}, title = {Substrate Reactivity Effects in the Atomic Layer Deposition of Aluminum Oxide from Trimethylaluminum on Ruthenium}, series = {Chemistry of Materials}, volume = {23}, journal = {Chemistry of Materials}, number = {13}, issn = {0897-4756}, pages = {3159 -- 3168}, language = {en} } @misc{TallaridaFriedrichStaedteretal., author = {Tallarida, Massimo and Friedrich, Daniel and St{\"a}dter, Matthias and Michling, Marcel and Schmeißer, Dieter}, title = {Growth of TiO2 with Thermal and Plasma Enhanced Atomic Layer Deposition}, series = {Journal of Nanoscience and Nanotechnology}, volume = {11}, journal = {Journal of Nanoscience and Nanotechnology}, number = {9}, issn = {1533-4880}, pages = {8049 -- 8053}, language = {en} } @misc{TallaridaKaravaevSchmeisser, author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {Novel "In-situ2" Approach to Modified ALD Processes for Nano-functional Metal Oxide Films}, language = {en} } @misc{KaravaevKolanekTallaridaetal., author = {Karavaev, Konstantin and Kolanek, Krzysztof and Tallarida, Massimo and Schmeißer, Dieter}, title = {In-Situ Studies of ALD Growth of Hafnium Oxide Films}, language = {en} } @article{HenkelKaravaevTorcheetal., author = {Henkel, Karsten and Karavaev, Konstantin and Torche, Mohamed and Schwiertz, Carola and Burkov, Yevgen and Schmeißer, Dieter}, title = {Al-Oxyxynitride interfacial layer investigations for PrXOY on SiC and Si}, language = {en} } @incollection{MuellerSchmeisser, author = {M{\"u}ller, S. and Schmeißer, Dieter}, title = {Deposition of reactive and non-reactive metals on titanium dioxide - chromium and cobalt}, language = {en} } @article{TallaridaSchmeisser, author = {Tallarida, Massimo and Schmeißer, Dieter}, title = {Study of bulk and interface defects in silicon oxide with X-ray absorption spectroscopy}, language = {en} } @inproceedings{KaravaevTallaridaSchmeisser, author = {Karavaev, Konstantin and Tallarida, Massimo and Schmeißer, Dieter}, title = {In-situ Atomic Layer Deposition growth of Hafnium oxide}, series = {DEDIS-Nano-Days, October 11th and October 12th, 2007}, booktitle = {DEDIS-Nano-Days, October 11th and October 12th, 2007}, editor = {Vierhaus, Heinrich Theodor}, publisher = {BTU}, address = {Cottbus}, pages = {13 -- 19}, language = {en} } @article{BieniekBeckJakubowskietal., author = {Bieniek, Tomasz and Beck, Romuald B. and Jakubowski, Andrzej and Hoffmann, Patrick and Schmeißer, Dieter and Konarski, Piotr and Cwil, M.}, title = {Formation of Pedestal Oxynitride Layer by Extremely Shallow Nitrogen Implantation in Planar R.F. Plasma Reactor}, language = {en} } @article{TallaridaSohalSchmeisser, author = {Tallarida, Massimo and Sohal, Rakesh and Schmeißer, Dieter}, title = {Resonant photoemission at the Oxygen K edge as a tool to study the eletronic properties of defects at SiO2/Si and SiO2/SiC interfaces}, language = {en} } @misc{HoffmannWehnerSchmeisseretal., author = {Hoffmann, Patrick and Wehner, Stefan and Schmeißer, Dieter and Brand, Helmut R. and K{\"u}ppers, J{\"u}rgen}, title = {Noise-induced spatiotemporal patterns in a bistable reaction-diffusion system: Photoelectron emission micrsoscopy experiments and modeling of the CO oxidation reaction on Ir(111)}, series = {Physical Review : E}, volume = {73}, journal = {Physical Review : E}, number = {5}, issn = {1550-2376}, pages = {056123}, language = {en} } @inproceedings{HenkelTorcheSohaletal., author = {Henkel, Karsten and Torche, Mohamed and Sohal, Rakesh and Schwiertz, Carola and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Pr-O-N Dielectrics for MIS Stacks on Silicon and Silicon Carbide Surfaces}, series = {Silicon carbide 2006 - materials, processing and devices, symposium held April 18 - 20, 2006, San Francisco, California, U.S.A.}, booktitle = {Silicon carbide 2006 - materials, processing and devices, symposium held April 18 - 20, 2006, San Francisco, California, U.S.A.}, editor = {Dudley, Michael}, publisher = {Materials Research Society}, address = {Warrendale, Pa.}, isbn = {978-1-55899-867-4}, pages = {353 -- 358}, language = {en} } @misc{BeerbomMayerJaegermannetal., author = {Beerbom, Martin and Mayer, Thomas and Jaegermann, Wolfram and Batchelor, David R. and Schmeißer, Dieter}, title = {Electrochemically Induced Redox-Reactions on GaAs-Surfaces: High Resolution Photoemission Spectra Taken at the U49/2 Beamline}, language = {en} } @article{HoffmannMikaloBatcheloretal., author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Batchelor, David R. and Schmeißer, Dieter and Soinski, M. S. and Follath, Rolf}, title = {The chromatic aberration of PEEM - demonstration on graphite inclusions in cast iron, Kategrorie: Microscopy - Spectromicroscopy}, language = {en} } @article{SieberMantelSeylleretal., author = {Sieber, N. and Mantel, B. F. and Seyller, Th. and Ristein, J. and Ley, L. and Heller, Thomas and Batchelor, David R. and Schmeißer, Dieter}, title = {Structural, electronic and chemical properties of hydrogen terminated 6H-SiC}, language = {en} } @article{GraupnerSeyllerLeyetal., author = {Graupner, R. and Seyller, Th. and Ley, L. and Mikalo, Ricardo Pablo and Hoffmann, Patrick and Batchelor, David R. and Schmeißer, Dieter}, title = {PEEM Investigation of CVD-Diamond grown on Si}, language = {en} } @article{HoffmannMikaloBatcheloretal., author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Batchelor, David R. and Schmeißer, Dieter and Follath, Rolf}, title = {N2O-Oxidation of Si(100)}, language = {en} } @article{MikaloHoffmannBatcheloretal., author = {Mikalo, Ricardo Pablo and Hoffmann, Patrick and Batchelor, David R. and Schmeißer, Dieter}, title = {Valence band spectroscopy of semiconducting regioregular Poly(3-Hexylthiophene)-2,5-diyl}, language = {en} } @inproceedings{MuellerPaloumpaSchmeisser, author = {M{\"u}ller, Klaus and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Carbon-Plot-Micostructuring for All-Polymer-Transistors}, language = {en} } @article{YfantisSchmeisserKompotiatis, author = {Yfantis, Alexandros D. and Schmeißer, Dieter and Kompotiatis, L.}, title = {Polypyrrole based conversion coatings for aluminium alloys}, language = {en} } @article{LopezBitzerHelleretal., author = {Lopez, A. and Bitzer, Thomas and Heller, Thomas and Richardson, Neville V.}, title = {Functional group selectivity in adsorption of 4-aminobenzoic acid on clean and Na modified Si(100)-2 x 1 surfaces}, language = {en} } @article{SieberSeyllerGraupneretal., author = {Sieber, N. and Seyller, Th. and Graupner, R. and Ley, L. and Mikalo, Ricardo Pablo and Batchelor, David R. and Schmeißer, Dieter}, title = {PES and LEED study of hydrogen and oxygen terminated 6H-SiC(0001) and (000-1) surfaces}, language = {de} } @inproceedings{YfantisBourdasLambrakopoulosetal., author = {Yfantis, Alexandros D. and Bourdas, N. and Lambrakopoulos, S. and Yfantis, N. and Paloumpa, Ioanna and Yfantis, Alexandros D.}, title = {Conductive polymers precoats-application on metallisation of ABS}, language = {en} } @inproceedings{YfantisBourdasLambrakopoulosetal., author = {Yfantis, Alexandros D. and Bourdas, N. and Lambrakopoulos, S. and Yfantis, N. and Paloumpa, Ioanna and Yfantis, Alexandros D.}, title = {Primers of conductive polymers-application in powder coatings technology}, language = {en} } @inproceedings{YfantisBourdasYfantisetal., author = {Yfantis, Alexandros D. and Bourdas, N. and Yfantis, N. and Yfantis, Alexandros D. and Lambrakopoulos, S. and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {A study of anticorrosive conversion coatings based on conductive polymers of pyrrole}, language = {en} } @misc{YfantisSchmeisser, author = {Yfantis, Alexandros D. and Schmeißer, Dieter}, title = {Method of chemical deposition of compose conductive polymer coatings on aluminium alloy surfaces}, language = {en} } @article{HenkelSchmeisser, author = {Henkel, Karsten and Schmeißer, Dieter}, title = {Back-propagation based neural network with a two sensor system for monitoring of carbon dioxide and relative humidity}, language = {en} } @article{LopezHellerBitzeretal., author = {Lopez, A. and Heller, Thomas and Bitzer, Thomas and Chen, Q. and Richardson, Neville V.}, title = {The influence of sodium on the adsorption of water on SrTiO3(100)-1x1 surfaces}, language = {en} } @techreport{SchwiertzHenkelPaloumpaetal., author = {Schwiertz, Carola and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter and Kamieth, P. and Schnegber, P.}, title = {Aufbau eines Sensorarrays zur Detektion von umwelt- und tierphysiologisch relevanten Komponenten}, language = {de} } @techreport{HenkelPaloumpaSchwiertzetal., author = {Henkel, Karsten and Paloumpa, Ioanna and Schwiertz, D. and Schmeißer, Dieter and Kamieth, P. and Schengber, P.}, title = {Gezielte Entwicklung von Sensormaterialien und Sensoren zur spezifischen Detektion von schwefel- und stickstoffhaltigen Stoffgruppen}, language = {de} } @article{HenkelPaloumpaSchwiertzetal., author = {Henkel, Karsten and Paloumpa, Ioanna and Schwiertz, B. and Elling, B. and Danz, R. and B{\"u}chtemann, A. and Straube, Oliver and Schmeißer, Dieter}, title = {Kraftsensoren aus Polymerfolien-Piezoelektrische Polymersensoren f{\"u}r Hochdruckanwendungen}, language = {de} } @article{KraftThissenMayeretal., author = {Kraft, D. and Thißen, A. and Mayer, Thomas and Klein, A. and Jaegermann, Wolfram and Hoffmann, Patrick and Batchelor, David R. and Schmeißer, Dieter}, title = {Backcontact Formation on CdTe Thin Film Solar Cells}, language = {en} } @article{BitzerLopezHelleretal., author = {Bitzer, Thomas and Lopez, A. and Heller, Thomas and Richardson, Neville V.}, title = {The Adsorption of maleic anhydride on Si(100)-2x1: A combined HREELS and NEXAFS study}, language = {en} } @techreport{HenkelPaloumpaOpreaetal., author = {Henkel, Karsten and Paloumpa, Ioanna and Oprea, A. and Appel, G{\"u}nter and Schmeißer, Dieter and Frandsen, W. and Sch{\"o}lzel, Mario}, title = {Entwicklung von Sensoren mit Elektroden aus leitf{\"a}higen Polymeren}, language = {de} } @article{BatchelorScheerSchmeisser, author = {Batchelor, David R. and Scheer, M. and Schmeißer, Dieter}, title = {WAVE Calculations of Off Axis Undulator Radiation for the BESSY II U49 Undulator}, language = {en} } @article{HoffmannSchmeisserKleinetal., author = {Hoffmann, Patrick and Schmeißer, Dieter and Klein, A. and Jaegermann, Wolfram and Pettenkofer, Christian and Follath, Rolf}, title = {Spectro-Microscopy with PEEM / µESCA}, language = {en} } @article{MikaloAppelHoffmannetal., author = {Mikalo, Ricardo Pablo and Appel, G{\"u}nter and Hoffmann, Patrick and Schmeißer, Dieter and Mast, M.}, title = {Multi-Atom Resonant Photoemission applied to study the silver to nitrogen interaction in polypyrrole films}, language = {en} } @inproceedings{HoffmannMikaloBatcheloretal., author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Batchelor, David R. and Beuckert, Guido and Schmeißer, Dieter and Kittler, Martin and Ourmazd, A. and Lewerenz, Hans-Joachim}, title = {Solare Energieumwandlung in d{\"u}nnen Schichten}, language = {de} } @inproceedings{HoffmannBatchelorSchmeisser, author = {Hoffmann, Patrick and Batchelor, David R. and Schmeißer, Dieter}, title = {Spectro-Microscopic analyses in metallurgical systems: spheroidic graphite in cast iron and the interface of friction-welded Al-Fe joints}, language = {en} } @article{SchmeisserAppelBoehmeetal., author = {Schmeißer, Dieter and Appel, G{\"u}nter and B{\"o}hme, O. and Heller, Thomas and Mikalo, Ricardo Pablo and Hoffmann, Patrick and Batchelor, David R.}, title = {Nanoparticles and polarons: active centers in thin film sensor devices}, language = {de} } @article{AppelMikaloHenkeletal., author = {Appel, G{\"u}nter and Mikalo, Ricardo Pablo and Henkel, Karsten and Oprea, A. and Yfantis, Alexandros D. and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Polymeric Electrodes}, language = {en} } @article{HoffmannMikaloSchmeisser, author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Schmeißer, Dieter}, title = {A spectro-microscopic approach for spatially resolved characterisation of semiconductor structures in PEEM}, language = {en} } @article{SchmeisserRichterPfitzneretal., author = {Schmeißer, Dieter and Richter, H. and Pfitzner, L. and Prasad, S.}, title = {E-MRS 1999 Spring Meeting, Strasbourg, June1-4,1999-Preface}, language = {en} } @article{YfantisYfantisTzalasetal., author = {Yfantis, Alexandros D. and Yfantis, Alexandros D. and Tzalas, B. and Schmeißer, Dieter}, title = {A new chrome - free passivation method of tinplate used in the canning industry}, language = {en} } @article{HellerBoehmeSchmeisser, author = {Heller, Thomas and B{\"o}hme, O. and Schmeißer, Dieter}, title = {Polarons in oxidic semiconductors - the SrTiO3 case}, language = {en} } @article{MikaloAppelHoffmannetal., author = {Mikalo, Ricardo Pablo and Appel, G{\"u}nter and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Determination of the Vacuum Level in NEXAFS-spectra by Selected-Yield-NEXAFS}, language = {en} } @misc{BatchelorSchmeisserFollath, author = {Batchelor, David R. and Schmeißer, Dieter and Follath, Rolf}, title = {The BTU Cottbus Beamline at BESSY II}, language = {de} } @article{HoffmannMikaloSchmeisser, author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Schmeißer, Dieter}, title = {Photoemissionselektronenmikroskopie - ein Instrument f{\"u}r die Materialforschung}, language = {de} } @article{AppelBoehmeMikaloetal., author = {Appel, G{\"u}nter and B{\"o}hme, O. and Mikalo, Ricardo Pablo and Schmeißer, Dieter}, title = {The polaron and bipolaron contributions to the electronic structure of polypyrrole films}, language = {en} } @article{SchmeisserBoehmeYfantisetal., author = {Schmeißer, Dieter and B{\"o}hme, O. and Yfantis, Alexandros D. and Heller, Thomas and Batchelor, David R. and Lundstr{\"o}m, Ingemar and Lloyd Spetz, Anita}, title = {Dipole moment of nanoparticles at interfaces}, language = {de} } @article{HoffmannMikaloSchmeisseretal., author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and Schmeißer, Dieter and Kittler, Martin}, title = {A spectro-microscopic approach to study the morphology and elemental distribution of mc-Si surfaces}, language = {en} } @article{OpreaHenkelOehmgenetal., author = {Oprea, A. and Henkel, Karsten and Oehmgen, R. and Appel, G{\"u}nter and Schmeißer, Dieter and Lauer, H. and Hausmann, P.}, title = {Increased sensor sensitivities obtained by polymer coated quartz microbalances}, language = {en} } @article{MikaloHoffmannHelleretal., author = {Mikalo, Ricardo Pablo and Hoffmann, Patrick and Heller, Thomas and Batchelor, David R. and Appel, G{\"u}nter and Schmeißer, Dieter}, title = {Doping and defect inhomogeneities of polypyrrole tosylate films as revealed by ?-NEXAFS}, language = {en} } @article{YfantisAppelSchmeisseretal., author = {Yfantis, Alexandros D. and Appel, G{\"u}nter and Schmeißer, Dieter and Yfantis, Alexandros D.}, title = {Polypyrrole doped with fluoro-metal complexes: thermal stability and structural properties}, language = {en} } @article{AppelSchmeisserBaueretal., author = {Appel, G{\"u}nter and Schmeißer, Dieter and Bauer, Jakob and Bauer, Monika and Egelhaaf, H. J. and Oelkrug, D.}, title = {The formation of oligomers in the electrolyte upon polymerization of pyrrole}, language = {en} } @article{BatchelorFollathSchmeisser, author = {Batchelor, David R. and Follath, Rolf and Schmeißer, Dieter}, title = {The optical design of a PGM for the Undulator U49/2 at BESSY II}, language = {en} } @article{HellerBoehmeTontietal., author = {Heller, Thomas and B{\"o}hme, O. and Tonti, D. and Klein, A. and Jaegermann, Wolfram and Schmeißer, Dieter}, title = {Na interaction with relaxed WO3 thin films}, language = {en} } @article{AppelBoehmeSchmeisser, author = {Appel, G{\"u}nter and B{\"o}hme, O. and Schmeißer, Dieter}, title = {NEXAFS-Spectroscopy of Differently Doped Polypyrroles}, language = {en} } @article{HoffmannMikaloBoehmeetal., author = {Hoffmann, Patrick and Mikalo, Ricardo Pablo and B{\"o}hme, O. and Schmeißer, Dieter}, title = {PEEM-investigations on cleaved MoTe2-surfaces}, language = {en} } @article{MikaloHoffmannBoehmeetal., author = {Mikalo, Ricardo Pablo and Hoffmann, Patrick and B{\"o}hme, O. and Schmeißer, Dieter}, title = {Doping inhomogenities in Polypyrrole films: a Photoemission Electron Microscope (PEEM) and Spectro-Microscopic Study}, language = {en} } @article{NaarmannSchmeisserBartletal., author = {Naarmann, H. and Schmeißer, Dieter and Bartl, A. and Dunsch, L. and G{\"o}pel, W.}, title = {Electronic and magnetic properties of polypyrrole films depending on their 1-dimensional and 2-dimensional microstructures}, language = {en} } @article{MikaloHoffmannHelleretal., author = {Mikalo, Ricardo Pablo and Hoffmann, Patrick and Heller, Thomas and Schmeißer, Dieter}, title = {Lateral Doping Inhomogeneities as Revealed by ?-NEXAFS and ?-PES}, language = {en} } @article{LloydSpetzSchmeisserBaranzahietal., author = {Lloyd Spetz, Anita and Schmeißer, Dieter and Baranzahi, A. and W{\"a}livaare, B. and G{\"o}pel, W. and Lundstr{\"o}m, Ingemar}, title = {X-ray photoemission and Auger electron spectroscopy analysis of fast responding activated metal oxide silicon carbide gas sensors}, language = {en} } @article{AppelYfantisGoepeletal., author = {Appel, G{\"u}nter and Yfantis, Alexandros D. and G{\"o}pel, W. and Schmeißer, Dieter}, title = {Highly conductive polypyrrole films on nonconductive substrates}, language = {en} } @inproceedings{GehrlichOhsiekKleinetal., author = {Gehrlich, Lukas and Ohsiek, Susanne and Klein, C. and Geiß, M. and Friedemann, Michael and K{\"u}cher, Peter and Schmeißer, Dieter}, title = {Ultrathin TaN/Ta barrier modifications to fullfill next technology node requirements}, series = {2011 IEEE International Interconnect Technology Conference and 2011 Materials for Advanced Metallization (IITC/MAM 2011), Dresden, Germany, 8 - 12 May 2011}, booktitle = {2011 IEEE International Interconnect Technology Conference and 2011 Materials for Advanced Metallization (IITC/MAM 2011), Dresden, Germany, 8 - 12 May 2011}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4577-0503-8}, doi = {10.1109/IITC.2011.5940322}, pages = {82 -- 84}, language = {en} } @misc{FriedrichHenkelRichteretal., author = {Friedrich, Daniel and Henkel, Karsten and Richter, Matthias and Schmeißer, Dieter}, title = {Fullerenol as probed by Synchrotron X-Ray Photoemission and Absorption Spectroscopy}, language = {en} } @article{BatchelorFollathMikaloetal., author = {Batchelor, David R. and Follath, Rolf and Mikalo, Ricardo Pablo and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Commissioning Results of the BTUC-PGM beamline}, language = {en} } @misc{KolanekTallaridaMichlingetal., author = {Kolanek, Krzysztof and Tallarida, Massimo and Michling, Marcel and Schmeißer, Dieter}, title = {In situ study of the atomic layer deposition of HfO2 on Si}, series = {Journal of Vacuum Science and Technology}, journal = {Journal of Vacuum Science and Technology}, number = {A 30}, issn = {0734-2101}, pages = {01A143-1 -- 01A143-15}, language = {en} } @inproceedings{MandalHenkelSchmeisser, author = {Mandal, Dipankar and Henkel, Karsten and Schmeißer, Dieter}, title = {Control of the Crystalline Polymorph, Molecular Dipole and Chain Orientations in P(VDF-HFP) for High Electrical Energy Storage Application}, series = {International Conference on Nanoscience, Technology and Societal Implications (NSTSI), 2011}, booktitle = {International Conference on Nanoscience, Technology and Societal Implications (NSTSI), 2011}, publisher = {IEEE}, isbn = {978-1-4577-2035-2}, doi = {10.1109/NSTSI.2011.6111801}, language = {en} } @misc{KlocekHenkelKolaneketal., author = {Klocek, Jolanta and Henkel, Karsten and Kolanek, Krzysztof and Broczkowska, K. and Schmeißer, Dieter and Miller, M. and Zschech, Ehrenfried}, title = {Studies of the chemical and electrical properties of fullerene and 3-aminopropyltrimethoxysilane based low-k materials}, series = {Thin Solid Films}, volume = {520}, journal = {Thin Solid Films}, number = {7}, issn = {0040-6090}, pages = {2498 -- 2504}, language = {en} } @misc{MandalHenkelSchmeisser, author = {Mandal, Dipankar and Henkel, Karsten and Schmeißer, Dieter}, title = {The electroactive Beta-phase formation in Poly(vinylidene fluoride) by gold nanoparticles doping}, series = {Materials Letters}, journal = {Materials Letters}, number = {73}, issn = {0167-577X}, pages = {123 -- 125}, language = {en} } @misc{KlocekHenkelKolaneketal., author = {Klocek, Jolanta and Henkel, Karsten and Kolanek, Krzysztof and Zschech, Ehrenfried and Schmeißer, Dieter}, title = {Annealing influence on siloxane based materials incorporated with fullerenes, phthalocyanines and silsesquioxanes}, series = {BioNanoScience}, volume = {2}, journal = {BioNanoScience}, number = {1}, issn = {2191-1630}, pages = {52 -- 58}, language = {en} } @misc{MuellerRichterPhilipetal., author = {M{\"u}ller, Klaus and Richter, Matthias and Philip, Shine and Kunst, Manuel and Schmeißer, Dieter}, title = {Excited states in P3HT and P3HT/PCBM blends}, series = {BioNanoScience}, volume = {2}, journal = {BioNanoScience}, number = {1}, issn = {2191-1630}, pages = {42 -- 51}, language = {en} } @misc{RichterFriedrichSchmeisser, author = {Richter, Matthias and Friedrich, Daniel and Schmeißer, Dieter}, title = {Valence and Conduction band states of PCBM as probed by photoelectron spectroscopy at resonant excitation}, series = {BioNanoScience}, volume = {2}, journal = {BioNanoScience}, number = {1}, issn = {2191-1630}, pages = {59 -- 65}, language = {en} } @misc{KlocekKolanekSchmeisser, author = {Klocek, Jolanta and Kolanek, Krzysztof and Schmeißer, Dieter}, title = {Spectroscopic and atomic force microscopy investigations of hybrid materials composed of fullerenes and 3-aminopropyltrimethoxysilane}, series = {Journal of Physics and Chemistry of Solids}, volume = {73}, journal = {Journal of Physics and Chemistry of Solids}, number = {5}, issn = {0022-3697}, pages = {699 -- 706}, language = {en} } @misc{KlocekHenkelKolaneketal., author = {Klocek, Jolanta and Henkel, Karsten and Kolanek, Krzysztof and Zschech, Ehrenfried and Schmeißer, Dieter}, title = {Spectroscopic and capacitance-voltage characterization of thin aminopropylmethoxysilane films doped with copper phthalocyanine, tris(dimethylvinylsilyloxy)-POSS and fullerene cages}, series = {Applied surface science}, volume = {258}, journal = {Applied surface science}, number = {10}, issn = {0169-4332}, pages = {4213 -- 4221}, language = {en} } @misc{MichlingSchmeisser, author = {Michling, Marcel and Schmeißer, Dieter}, title = {Resonant Photoemission at the O1s threshold to characterize β-Ga2O 3 single crystals}, series = {IOP Conference Series: Materials Science and Engineering}, journal = {IOP Conference Series: Materials Science and Engineering}, number = {34}, issn = {1757-8981}, doi = {10.1088/1757-899X/34/1/012002}, pages = {012002}, abstract = {We report on spectroscopic investigations on β-Ga2O3single crystals. We focus on the detailed analysis of the O1s resonance profile by resonant photoelectron spectroscopy. We analyze the electronic structure and assign the O2p to build the valence band and both, O2p and Ga4s4p states to contribute to the conduction band. We determine the partial density of states for the valence and conduction bands and find a strong hybridization of O2p and Ga4s states. This is deduced from constant final state spectra on the O-KLL-Auger over the O K-edge and Ga L2,3-edge and a comparison to the corresponding X-ray absorption spectroscopy data. We also identify several types of defects. A broad band of oxygen derived defects is identified that extends through-out the gap. Small polarons are attributed to cause an anti-resonance in the valence states around the O1s threshold. In addition, a separate Auger decay at resonance indicates the existence of localized charge transfer states which involves localized Ga4sp states.}, language = {en} } @misc{MuellerRichterFriedrichetal., author = {M{\"u}ller, Klaus and Richter, Matthias and Friedrich, Daniel and Paloumpa, Ioanna and Kramm, Ulrike Ingrid and Schmeißer, Dieter}, title = {Spectroscopic characterization of Cobalt-Phthalocyanine electrocatalysts for fuel cell applications}, series = {Solid State Ionics}, journal = {Solid State Ionics}, number = {216}, issn = {1872-7689}, doi = {10.1016/j.ssi.2011.12.013}, pages = {78 -- 82}, abstract = {For polymer-electrolyte-membrane fuel cells (PEM-FC), platinumcatalysts on carbon based substrates are state of the art, due to high electrochemical activity and chemical stability in acid electrolytes. High costs of platinum force investigations of alternative catalysts. With respect to the oxygen reduction reaction, possible candidates are transition metal (TM) complexes like TM-porphyrines or TM-phthalocyanines. Pyrolysis on carbon based substrates improves the catalytic activity. Highest activities were found for Fe or Co as transition metal centers. We present results of the pyrolysis of Co-phthalocyanine (CoPc) on carbon black. Besides an investigation of morphology by scanning electron microscopy (SEM) and chemical composition by energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) during pyrolysis, we present a near edge X-ray absorption fine structure (NEXAFS) study of the chemical composition for the related annealing steps. This investigation is accompanied by an electrochemical characterization of the catalytic activity and selectivity. The XPS and NEXAFS data indicate a decomposition of the CoN4(chelate-) complex during pyrolysis. The N1s data for 800 °C show graphite-like, formally pyrrolic and pyridinic like features, without any significant contri-bution of Co. The Co2p data for both, XPS and NEXAFS are dominated by CoO/Co2O3. It can be concluded that during the pyrolysis cobalt particles are formed by the disintegration of CoN4-centers, after pyrolysis these par-ticles become oxidized upon contact with air.}, language = {en} } @misc{KolanekTallaridaSchmeisser, author = {Kolanek, Krzysztof and Tallarida, Massimo and Schmeißer, Dieter}, title = {Height distribution of atomic force microscopy images as a tool for atomic layer deposition characterization}, series = {Journal of Vacuum Science and Technology : A}, volume = {31}, journal = {Journal of Vacuum Science and Technology : A}, number = {1}, doi = {10.1116/1.4754557}, pages = {01A104-1 -- 01A104-9}, abstract = {The authors propose the analysis of surface height histograms as a tool for the atomic layer deposition (ALD) growth characterization in the initial stage of the process. ALD of HfO2 on a Si(100)/SiO2 substrate was investigated in situ by ultra high vacuum atomic force microscope working in noncontact mode. The ALD cycles, made by using tetrakis-di-methyl-amido-Hf and H2O as precursors, were performed at 230 C. After each ALD cycle, the relation between the film growth and the root mean square surface roughness was studied. Parameters equivalent to HfO2 layer thickness, coverage, and surface roughness of the substrate and deposited material can be calculated in the proposed routine.}, language = {en} } @misc{KlocekKolanekHenkeletal., author = {Klocek, Jolanta and Kolanek, Krzysztof and Henkel, Karsten and Zschech, Ehrenfried and Schmeißer, Dieter}, title = {Influence of the fullerene derivatives and cage polyhedral oligomeric silsesquioxanes on 3-aminopropyltrimethoxysilane based hybrid nanocomposites chemical, morphological and electrical properties}, series = {Journal of Physics and Chemistry of Solids}, volume = {74}, journal = {Journal of Physics and Chemistry of Solids}, number = {1}, issn = {0022-3697}, doi = {10.1016/j.jpcs.2012.08.013}, pages = {135 -- 145}, abstract = {In this study we produced 3-aminopropyltrimethoxysilane based hybrid nanocomposites using fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as nanodopants. Additionally, we modified obtained material with incompletely condensed cage polyhedral oligomeric silsesqiuox-anes (POSS) in order to improve its properties. Thin films were deposited by means of the spin-coating method. The films were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and capacitance-voltage (CV) measurements. We observed that a properly chosen PCBM concentration may be a crucial factor to obtain high quality APTMS based films by the spin-coating technique. XPS revealed the presence of the C-NH-C species within POSS containing films indicating chemical interaction between the amino group of APTMS and the POSS molecules. AFM results suggest that at high POSS monomer concentration in the range of 1\% the creation of fractal-shaped aggregates takes place. The CV characterization of the samples exhibits a decrease of the APTMS based films dielectric constant due to the POSS and PCBM contribution. The combination of the applied methods delivers complementary information concerning the properties of the analyzed films.}, language = {en} } @misc{KukliDimriTammetal., author = {Kukli, Kaupo and Dimri, Mukesh Chandra and Tamm, Aile and Kemell, Marianna and K{\"a}{\"a}mbre, Tanel and Vehkam{\"a}ki, Marko and Puttaswamy, Manjunath and Stern, Raivo and Kuusik, Ivar and Kikas, Arvo and Tallarida, Massimo and Schmeißer, Dieter and Ritala, Mikko and Leskel{\"a}, Markku}, title = {Structural and Magnetic Studies on Iron Oxide and Iron-Magnesium Oxide Thin Films Deposited Using Ferrocene and (Dimethylaminomethyl)ferrocene Precursors}, series = {ECS Journal of Solid State Science and Technology}, volume = {2}, journal = {ECS Journal of Solid State Science and Technology}, number = {3}, issn = {2162-8769}, doi = {10.1149/2.004303jss}, pages = {N45 -- N54}, abstract = {Iron oxide and magnesium-doped iron oxide films were grown by atomic layer deposition in the temperature range of 350-500 ◦C from ferrocene, (dimethylaminomethyl)ferrocene, magnesiumβ-diketonate, and ozone. Phase composition of the films depended on the deposition temperature, as magnetite and/or maghemite tended to form instead of hematite upon lowering the temperature. Iron oxide layers were also mixed with magnesium oxide by alternate deposition of MgO and Fe2O3 which also favored the formation of magnetite or maghemite structure prior to hematite. Scanning electron microscopy implied the smoothening of the films after doping with magnesium oxide. Magnetometry was used to study the effects of temperature and doping levels on the magnetic properties of the films.}, language = {en} } @misc{PopoviciDelabieAdelmannetal., author = {Popovici, Mihaela and Delabie, Annelies and Adelmann, Christoph and Meersschaut, Johan and Franquet, Alexis and Tallarida, Massimo and Berg, Jaap van den and Richard, Olivier and Swerts, Johan and Tomida, Kazuyuki and Kim, Min-Soo and Tielens, Hilde and Bender, Hugo and Conard, Thierry and Jurczak, Malgorzata and Elshocht, Sven van and Schmeißer, Dieter}, title = {Understanding the Interface Reactions of Rutile TiO2 Grown by Atomic Layer Deposition on Oxidized Ruthenium}, series = {ECS Journal of Solid State Science and Technology}, volume = {2}, journal = {ECS Journal of Solid State Science and Technology}, number = {1}, issn = {2162-8769}, doi = {10.1149/2.035301jss}, pages = {N23 -- N27}, abstract = {The atomic layer deposition of titanium oxide TiO2 on ruthenium and oxidized ruthenium with titanium methoxide as metal precursor and H2O and O3 as oxidant was investigated by Rutherford backscattering (RBS) and time of flight secondary ion mass spectrometry (TOFSIMS). An ultra-thin layer of TiO2 deposited a priori with H2O plays the role of protection of Ru(Ox) substrates against etching by O3. Information about thin films (∼3 nm) interfacial reactions, thickness and structure was brought by Medium Energy Ion Scattering Spectroscopy (MEIS) and X-ray absorption spectroscopy (XAS) measurements. The growth enhancements observed in the first stages of the deposition depends on the pre-treatment (pre-oxidation, H2O based interlayer thickness) of the Ru substrate. Thick films (∼14 nm) were analyzed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The as deposited TiO2 films are crystalline with rutile structure, as resulted from structural analyzes. However, the presence of small amounts of anatase was detected by soft X-ray absorption spectroscopy (XAS) and is strongly influenced by the surface pre-treatment of the Ru substrate. The electrical properties (equivalent oxide thickness and leakage current density) correlate with a different rutile/anatase ratio present in the films.}, language = {en} } @misc{FischerRohrbeckWehneretal., author = {Fischer, Christian B. and Rohrbeck, Magdalena and Wehner, Stefan and Richter, Matthias and Schmeißer, Dieter}, title = {Interlayer formation of diamond-like carbon coatings on industrial polyethylene: Thickness dependent surface characterization by SEM, AFM and NEXAFS}, series = {Applied Surface Science}, journal = {Applied Surface Science}, number = {271}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2013.01.210}, pages = {381 -- 389}, abstract = {The coating of materials with diamond-like carbon (DLC) is a very common way to change and improve their basic characteristics. Although DLC is used on several substrates, the chemical and physical properties throughout the coating process on plastics are yet sparsely investigated. Two types of protective coatings one sp3-enriched (robust, r-type) and one with more sp2-centers (flexible, f-type) have been realized on polyethylene by PECVD deposition. SEM and AFM analysis of coated samples of DLC types revealed diverse surface topographies on different scales and images appeared even differently smoothed by the carbonaceous deposits. Grains of both DLC types are platelet-shaped and nearly double in size for the robust type indicating fundamental differences in the epitaxial DLC growth. NEXAFS spectroscopy showed significant details of carbon centers in chemically different neighborhood displaying a characteristic fingerprint behavior. Comparison of deposition models revealed a mechanism of interlayer formation which is discussed in detail. Interlayer formation is clearly the appropriate explanation of the process for the current carbon deposition between these two unequal materials. An improved understanding of hard DLC and soft polyethylene assembly is given in the presented work.}, language = {en} } @misc{RichterPaloumpaFriedrichetal., author = {Richter, Matthias and Paloumpa, Ioanna and Friedrich, Daniel and Schmeißer, Dieter}, title = {Multiple Auger Decay At Resonant Photo-Excitation In Carbon Thin Films}, series = {ECS Transactions}, volume = {50}, journal = {ECS Transactions}, number = {20}, doi = {10.1149/05020.0009ecst}, pages = {9 -- 21}, abstract = {We use resonant photoemission at the C1s edge to study the electronic structure of HOPG, graphene flakes and monolayer graphene. We find remarkable differences in the profile of the Auger decay channels, which we attribute to an additional multiple-Auger with a three-hole final state. A prerequisite for the appearance of this decay mechanism is the existence of localized excitonic states, which cause the appearance of the multiple Auger decay. We use those effects to identify the existence and the quantity of such defect states within the π*-band regime in carbon thin films, because the intensity of the three-hole Auger decay is varying with the defect density of the carbon films. We find that the appearance of the multiple Auger decay is different for multilayer and monolayer graphene. In particular the interaction of impurities leads to broadening of the C1s core levels. The three-hole Auger decay spectroscopy is a new method to detect such contaminations with a high sensitivity.}, language = {en} } @misc{RichterSchmeisser, author = {Richter, Matthias and Schmeißer, Dieter}, title = {Spin states in Co-PI catalysts}, series = {Applied Physics Letters}, journal = {Applied Physics Letters}, number = {102}, issn = {1077-3118}, doi = {10.1063/1.4811748}, pages = {253904-1 -- 253904-4}, abstract = {Cobalt based oxygen evolution catalysts (Co-PI, PI=electrodeposited from pH 7 phosphate) are studied by resonant photoemission spectroscopy at the Co L3 and O1s edge. For the individual Co3d states, we determine their configuration, their spin, and their energy level relative to the Fermi energy. We identify the Co divalent high spin state and the trivalent low spin state. In addition, we also find the corresponding oxygen-to-metal charge transfer states. We attribute the trivalent charge transfer state to be the active state for the oxygen evolution reaction.}, language = {en} } @misc{RichterSchmeisser, author = {Richter, Matthias and Schmeißer, Dieter}, title = {The Co2p Oxidation State In Co-PI Catalysts}, series = {ECS Transactions}, volume = {50}, journal = {ECS Transactions}, number = {49}, doi = {10.1149/05049.0113ecst}, pages = {113 -- 126}, abstract = {The electronic structure of Cobalt based catalysts used for photocatalytic water splitting in solar cells is analyzed using synchrotron radiation photoelectron spectroscopy. The catalyst films are prepared by electrochemical deposition. We employ a X-ray photoelectron spectroscopy study to analyze the Co2p and O1s core levels,absorption edges and valence bands. We discuss our resonant data in terms of the partial density of states of the valence and conduction band. We find a difference in the Co oxidation state as a function of film thickness (deposited charge). From the relative amount of Co, O, K and P we favor the molecular cobaltate cluster-like structure as the structural motif of the Co-PI catalyst.}, language = {en} } @misc{TallaridaSchmeisser, author = {Tallarida, Massimo and Schmeißer, Dieter}, title = {In situALD experiments with synchrotron radiation photoelectron spectroscopy}, series = {Semiconductor Science and Technology}, volume = {27}, journal = {Semiconductor Science and Technology}, number = {7}, issn = {1361-6641}, doi = {10.1088/0268-1242/27/7/074010}, pages = {074010}, abstract = {In this contribution, we describe some features of atomic layer deposition (ALD) investigated by means of synchrotron radiation photoelemission spectroscopy (SR-PES). In particular, we show how the surface sensitivity of SR-PES combined with the in situ nature of our investigations can point out interactions between the substrate and ALD precursors. We observed changes on all substrates investigated, included Si, GaAs, Ru and their surface oxides. These interactions are extremely important during the first ALD cycles and induce modifications in the substrate, which might lead to its functionality enhancement.}, language = {en} } @misc{SchmidtSchmeisser, author = {Schmidt, Stephan and Schmeißer, Dieter}, title = {Electronic structure of cobalt-nickel mixed oxides}, series = {Solid State Ionics}, journal = {Solid State Ionics}, number = {225}, issn = {1872-7689}, doi = {10.1016/j.ssi.2012.06.009}, pages = {737 -- 741}, abstract = {We investigate the electronic structure of cobalt-nickel mixed oxides by means of SR-based electron spectroscopy. We vary the Co-Ni content systematically and find that the most significant changes in the spectroscopic data occur at a mixing ratio of 30/70. We analyze the electronic structure of this material in detail and we are able to distinguish between pure covalent contributions, which cause a band gap of about 6 eV and empty defect states, whichfill the band gap almost completely. These defects are associated with the formation of 3d7L charge transfer states. These are correlated defect states and are identified by resonant photo-emission spectroscopy.}, language = {en} } @misc{MandalMuellerHenkeletal., author = {Mandal, Dipankar and M{\"u}ller, Klaus and Henkel, Karsten and Schmeißer, Dieter}, title = {The effect of X-ray photoelectron spectroscopy measurement on P(VDF-TrFE) copolymer thin films}, series = {Applied Surface Science}, journal = {Applied Surface Science}, number = {261}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2012.07.144}, pages = {209 -- 213}, abstract = {The impact of prolonged X-ray irradiation during X-ray photoelectron spectroscopy (XPS) measurement was investigated on poly(vinylidene-trifluoroethylene) (P(VDF-TrFE)) thin films. It was observed that prolonged X-ray irradiation can accelerate the crosslinking of P(VDF-TrFE) and diminish the ferroelectric phase. Fourier transform infrared spectroscopy (FT-IR) data indicate that the ferroelectric phase diminishes completely after 360 kJ of X-ray irradiation dose and it induces the paraelectric phase. In this work, the main emphasis was given to the optimization of the X-ray irradiation dose during XPS measurements to maintain the ferroelectric phase within the copolymer films.}, language = {en} } @misc{TallaridaAdelmannDelabieetal., author = {Tallarida, Massimo and Adelmann, Christoph and Delabie, Annelies and van Elshocht, Sven and Caymax, Matty and Schmeißer, Dieter}, title = {GaAs clean up studied with synchrotron radiation photoemission}, series = {IOP Conference Series : Materials Science and Engineering}, journal = {IOP Conference Series : Materials Science and Engineering}, number = {41}, issn = {1757-899X}, doi = {10.1088/1757-899X/41/1/012003}, pages = {012003}, abstract = {In this contribution we describe the chemical changes at the surface of GaAs upon adsorption of tri-methyl-aluminum (TMA). TMA is used to grow Al2O3 with atomic layer deposition (ALD) usually using H2O as oxygen source. Recently, it was pointed out that the adsorption of TMA on various III-V surfaces reduces the native oxide, allowing the growth of an abrupt III-V/High-K interface with reduced density of defects. Synchrotron radiation photoemission spectroscopy (SR-PES) is a powerful method to characterize surfaces and interfaces of many materials, as it is capable todetermine their chemical composition as well as the electronic properties. We performed in-situ SR-PES measurements after exposing a GaAs surface to TMA pulses at about 250°C. Upon using the possibility of tuning the incident photon energy we compared the Ga3d spectra at 41 eV, 71 eV, 91 eV and 121 eV, as well as the As3d at 71 eV and 91 eV. Finally, we show that using SR-PES allows a further understanding of the surface composition, which is usually not accessible with other techniques.}, language = {en} } @inproceedings{RichterSchmeisser, author = {Richter, Matthias and Schmeißer, Dieter}, title = {The Co2p oxidation state in Co-PI catalysts}, series = {Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012}, booktitle = {Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012}, publisher = {The Electrochemical Society}, pages = {1803}, language = {en} } @inproceedings{RichterFriedrichSchmeisser, author = {Richter, Matthias and Friedrich, Daniel and Schmeißer, Dieter}, title = {Multiple Auger decay at resonant photo-excitation in carbon thin films}, series = {Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012}, booktitle = {Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012}, publisher = {The Electrochemical Society}, pages = {3509}, language = {en} } @inproceedings{SchmeisserRichterTallarida, author = {Schmeißer, Dieter and Richter, Matthias and Tallarida, Massimo}, title = {Intrinsic defects in TiO2 to explain resistive switching devices}, series = {Frontiers in Electronic Materials: A Collection of Extended Abstracts of the Nature Conference Frontiers in Electronic Materials, June 17 to 20 2012, Aachen, Germany}, booktitle = {Frontiers in Electronic Materials: A Collection of Extended Abstracts of the Nature Conference Frontiers in Electronic Materials, June 17 to 20 2012, Aachen, Germany}, editor = {Heber, J{\"o}rg and Schlom, Darrell and Tokura, Yoshinori and Waser, Rainer and Wuttig, Matthias}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {978-3-527-41191-7}, doi = {10.1002/9783527667703.ch45}, pages = {255 -- 256}, language = {en} } @inproceedings{MandalHenkelDasetal., author = {Mandal, Dipankar and Henkel, Karsten and Das, Suken and Schmeißer, Dieter}, title = {Control of β- and γ-Phase formation in electroactive P(VDF-HFP) films by silver nano-particle doping}, series = {Frontiers in Electronic Materials: A Collection of Extended Abstracts of the Nature Conference Frontiers in Electronic Materials, June 17 to 20 2012, Aachen, Germany}, booktitle = {Frontiers in Electronic Materials: A Collection of Extended Abstracts of the Nature Conference Frontiers in Electronic Materials, June 17 to 20 2012, Aachen, Germany}, editor = {Heber, J{\"o}rg and Schlom, Darrell and Tokura, Yoshinori and Waser, Rainer and Wuttig, Matthias}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {978-3-527-41191-7}, doi = {10.1002/9783527667703.ch69}, pages = {640 -- 641}, language = {en} } @misc{KukliKemellPuukilainenetal., author = {Kukli, Kaupo and Kemell, Marianna and Puukilainen, Esa and Aarik, Jaan and Aidla, Aleks and Sajavaara, Timo and Laitinen, Mikko and Tallarida, Massimo and Sundqvist, Jonas and Ritala, Mikko and Leskel{\"a}, Markku}, title = {Atomic Layer Deposition of Ruthenium Films from (Ethylcyclopentadienyl)(pyrrolyl)ruthenium and Oxygen}, series = {Journal of the Electrochemical Society}, volume = {158}, journal = {Journal of the Electrochemical Society}, number = {3}, issn = {0013-4651}, doi = {10.1149/1.3533387}, pages = {D158 -- D165}, abstract = {Ru films were grown by atomic layer deposition in the temperature range of 275-350 degrees C using (ethylcyclopentadienyl)(pyrrolyl)ruthenium and air or oxygen as precursors on HF-etched Si, SiO(2), ZrO(2), and TiN substrates. Conformal growth was examined on three-dimensional silicon substrates with 20: 1 aspect ratio. ZrO(2) promoted the nucleation of Ru most efficiently compared to other substrates, but the films roughened quickly on ZrO(2) with increasing film thickness. The minimum number of cycles required to form continuous and conductive metal layers could be decreased by increasing the length of the oxygen pulse. In order to obtain well-conducting Ru films growth to thicknesses of at least 8-10 nm on any surface was necessary. Resistivities in the ranges of 30-60 and 14-16 mu Omega . cm were achieved for 4-6 and 10-15 nm thick films, respectively. Delamination became an issue in the Ru films grown to thicknesses about 10 nm and higher.}, language = {en} } @inproceedings{Tallarida, author = {Tallarida, Massimo}, title = {III-V/oxide interfaces investigated with synchrotron radiation photoemission spectroscopy}, series = {Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012}, booktitle = {Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012}, publisher = {The Electrochemical Society}, pages = {2587 -- 2587}, language = {en} } @misc{TallaridaAdelmannDelabieetal., author = {Tallarida, Massimo and Adelmann, Christoph and Delabie, Annelies and Elshocht, Sven van and Caymax, Matty and Schmeißer, Dieter}, title = {III-V/Oxide Interfaces Investigated with Synchrotron Radiation Photoemission Spectroscopy}, series = {ECS Transactions}, volume = {50}, journal = {ECS Transactions}, number = {4}, issn = {1938-6737}, doi = {10.1149/05004.0123ecst}, pages = {123 -- 128}, abstract = {We used synchrotron radiation photoemission spectroscopy (SR-PES) to investigate the surface of GaAs and other III-V semiconductors after tri-methyl-aluminum (TMA) pulses performed at 250{degree sign}C. We observed the removal of native oxide and the growth of Al-oxide upon measuring the As3d, Ga3d, Al2p and VB spectra. After seven TMA pulses we performed one water pulse. As3d and Ga3d peaks showed almost no lineshape change, but a decrease of intensity due to the water adsorption. The valence band shows a change in the secondary electron cut-off and the decrease of work function. We conclude that water mostly adsorbs molecularly and induces the work function decrease. The molecular absorption of water indicates that the seven TMA pulses produce a passivated surface only partially terminated with OH groups.}, language = {en} } @misc{MuellerFleigeRachowetal., author = {M{\"u}ller, Klaus and Fleige, Michael and Rachow, Fabian and Schmeißer, Dieter}, title = {Sabatier based CO2-methanation of flue gas emitted by conventional power plants}, series = {Energy Procedia}, volume = {40}, journal = {Energy Procedia}, issn = {1876-6102}, doi = {10.1016/j.egypro.2013.08.028}, pages = {240 -- 248}, abstract = {The hydrogenation CO2+ 4H2 ->CH4 + 2H2O discovered by Paul Sabatier nowadays is discussed as "Power-to-approach" to utilize excess energy from renewable electricity generation. In a laboratory scale, we investigate the Sabatier process in a simulated flue gas atmosphere of conventional base load power plants. The reaction is investigated with regard to conversion rates, yield, selectivity and long-term stability. Using a catalyst based on nickel,we extract selectivities near 100\% with a conversion around 85\%. Beside the influence of oxygen, we investigate further typical contaminations like NO2 and SO2.}, language = {en} } @inproceedings{MaiDauderstaedtPahneretal., author = {Mai, Andreas and Dauderst{\"a}dt, Ulrike and Pahner, D. and Krellmann, M. and Schmeißer, Dieter and Wagner, M.}, title = {In situ determination of laser induced degradation of micro-mirror arrays}, series = {International Students and Young Scientists Workshop Photonics and Microsystems, Cottbus, Germany, 8 - 10 June 2011}, booktitle = {International Students and Young Scientists Workshop Photonics and Microsystems, Cottbus, Germany, 8 - 10 June 2011}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4577-1651-5}, doi = {10.1109/STYSW.2011.6155850}, pages = {84 -- 88}, abstract = {The Fraunhofer Institute for Photonic Microsystems (Fraunhofer IPMS) develops spatial light modulators (SLMs) based on arrays of tiltable micro mirrors on a semiconductor chip. Typical applications are pattern generation for deepUV-laser mask writing or structured illumination in microscopy. Development and optimization of such SLMs requires detailed knowledge of the device behaviour under operating conditions. Here, the flatness of each single mirror effects the image resolution and contrast of the generated pattern and is amongst others a characteristic property of SLMs. In this context a surface topography measurement under laser exposure (in situ) was designed. The interferometric setup uses the phase-shift principle and allows a resolution in z-direction in the single-digit nanometer range. During irradiation with UV-laser light at 248 nm (KrF) and energy densities of up to 20 mJ/cm2 the change in single micro-mirrors topography was detected in situ. Measurementswith varying pulse energies were carried out to identify an impacton the device performance. In general, the setup is neither limited to a specific illumination wavelength nor to micro-mirrors as structures under test.}, language = {en} } @misc{BarrecaCarraroGasparottoetal., author = {Barreca, Davide and Carraro, Giorgio and Gasparotto, Alberto and Maccato, Chiara and Rossi, Francesca and Salviati, Giancarlo and Tallarida, Massimo and Das, Chittaranjan and Fresno, Fernando and Korte, Dorota and Štangar, Urška Lavrenčič and Franko, Mladen and Schmeißer, Dieter}, title = {Surface Functionalization of Nanostructured Fe2O3 Polymorphs: From Design to Light-Activated Applications}, series = {ACS Applied Materials \& Interfaces}, volume = {5}, journal = {ACS Applied Materials \& Interfaces}, number = {15}, issn = {1944-8252}, doi = {10.1021/am401475g}, pages = {7130 -- 7138}, abstract = {Nanostructured iron(III) oxide deposits are grown by chemical vapor deposition (CVD) at 400-500 °C on Si(100) substrates from Fe(hfa)2TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N′N′-tetramethylethylenediamine), yielding the selective formation of α-Fe2O3or the scarcely studiedε-Fe2O3 polymorphs under suitably optimized preparative conditions. By using Ti(OPr i)4(OPri= iso-propoxy) and water asatomic layer deposition (ALD) precursors, we subsequently functionalized the obtained materials at moderate temperatures (<300°C) by an ultrathin titanomagnetite (Fe3-xTixO4) overlayer. An extensive multitechnique character-ization, aimed at elucidating the system structure, morphology, composition and optical properties, evidenced that the photoactivated hydrophilic and photocatalytic behavior of the synthesized materials is dependent both on iron oxide phase composition and ALD surface modification. The proposed CVD/ALD hybrid synthetic approach candidates itself as a powerful tool for a variety of applications where semiconductor-based nanoarchitectures can benefit from the coupling with an ad hoc surface layer.}, language = {en} } @misc{AdelmannCuypersTallaridaetal., author = {Adelmann, Christoph and Cuypers, Daniel and Tallarida, Massimo and Rodriguez, Leonard and De Clercq, Astrid and Friedrich, Daniel and Conard, Thierry and Delabie, Annelies and Seo, Jin Won and Locquet, Jean-Pierre and De Gendt, Stefan and Schmeißer, Dieter and Elshocht, Sven van and Caymax, Matty}, title = {Surface Chemistry and Interface Formation during the Atomic Layer Deposition of Alumina from Trimethylaluminum and Water on Indium Phosphide}, series = {Chemistry of Materials}, volume = {25}, journal = {Chemistry of Materials}, number = {7}, issn = {1520-5002}, doi = {10.1021/cm304070h}, pages = {1078 -- 1091}, abstract = {The surface chemistry and the interface formation during the initial stages of the atomic layer deposition (ALD) of Al2O3 from trimethylaluminum (TMA) and H2O on InP(100)were studied by synchrotron radiation photoemission spectroscopy and scanning tunneling microscopy. The effect of the ex situ surface cleaning by either H2SO4 or (NH4)2S was examined. It is shown that the native oxide on the InP surface consisted mainly of indium hydrogen phosphates with a P enrichment at the interface with InP. After a (NH4)2S treatment, S was present on the surface as a sulfide in both surface and subsurface sites. Exposure to TMA led to the formation of a thin AlPO4 layer, irrespective of the surface cleaning. The surface Fermi level of p-type InP was found to be pinned close to midgap after H2SO4 cleaning and moved only slightly further toward the conduction band edge upon TMA exposure, indicating that the AlPO4/InP interface was rather defective. (NH4)2S passivation led to a Fermi level position of p-type InP close to the conduction band edge. Hence, the InP surface was weakly inverted, which can be attributed to surface doping by S donors. TMA exposure was found to remove surface S, which was accompanied by a shift of the Fermi level to midgap, consistent with the removal of (part of) the S donors in combination with a defective AlPO4/InP interface. Further TMA/H2O ALD did not lead to any detectable changes of the AlPO4/InP interface and suggested simple overgrowth with Al2O3.}, language = {en} } @misc{RossiFabbriTallaridaetal., author = {Rossi, Francesca and Fabbri, Filippo and Tallarida, Massimo and Schmeißer, Dieter and Modreanu, Mircea and Attolini, Giovanni and Salviati, Giancarlo}, title = {Structural and luminescence properties of HfO2 nanocrystals grown by atomic layer deposition on SiC/SiO2 core/shell nanowires}, series = {Scripta Materialia}, volume = {69}, journal = {Scripta Materialia}, number = {10}, issn = {1359-6462}, doi = {10.1016/j.scriptamat.2013.08.017}, pages = {744 -- 747}, abstract = {In this work we report the morphological, structural and luminescence properties of HfO2 nanocrystals grown on the surface of SiC/SiO2 core/shell nanowires by atomic layer deposition. All the studies are carried out in comparison with HfO2 nanocrystal aggregates grown on planar oxidized silicon substrates. The structural analyses reveal that HfO2has monoclinic structure with dif-ferent orientations. The cathodoluminescence emission shows the main components at 2.7 and 2.3 eV, deeply influenced by the arrangement and aggregation of the nanocrystals.}, language = {en} } @phdthesis{Klocek, author = {Klocek, Jolanta}, title = {Processing and investigation of thin films with incorporated carbon species for possible application as low-k materials}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-24358}, abstract = {In this thesis the detailed investigations concerning processing and stability of thin films including carbon species and their possible application as materials of a low dielectric constant (low k) are presented. In order to gather a complex information regarding the chemical, morphological and dielectric properties of the produced layer a combination of the spectroscopy: X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS) and Fourier transform infrared spectroscopy (FTIR), microscopy: atomic force microscopy (AFM) and electrical characterization: capacitance-voltage technique (CV) have been applied. The films deposited by means of variety of techniques have been described, ranging from evaporation, through spraying and dropping to spin-coating. Regarding the possible low-k application, a considerable attention has been paid to the hybrid organic-inorganic 3-aminopropyl-trimethoxysilane (APTMS) based composite materials enriched with carbon species coming from the following dopants: C60 fullerenes, [6,6]-phenyl-C61-butyric acid (PCBM), copper phthalocyanine (CuPc), and tris(dimethylvinylsilyloxy)-POSS (POSS). In the following thesis progressive steps leading to gradual decreasing of the resulting permittivity of the hybrid material is presented. As revealed by the performed investigations, the replacement of C60 within the APTMS based matrix by its better soluble derivative PCBM allows the increase of the concentration of the carbon species within the composite films. The introduction of POSS as an additional dopant gave the opportunity of increasing the resistance of the produced material against the ambient influence. With the excess of the POSS concentration an original fractal-shaped cluster formation has been observed. Finally, the dispersion of the properly chosen low concentration of CuPc and POSS molecules within the APTMS based matrix led to the fabrication of homogenous layer with an ultra-low dielectric constant of 1.8.}, language = {en} } @phdthesis{Kraatz, author = {Kraatz, Matthias}, title = {Studying the effect of Cu microstructure on electromigration reliability using statistical simulation}, pages = {XVI, 141 S.}, language = {en} } @phdthesis{Karavaev, author = {Karavaev, Konstantin}, title = {In-situ Atomic Layer Deposition growth of Hf-oxide}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-22617}, pages = {VIII, 57 Bl.}, abstract = {We have grown HfO2 on Si(001) by atomic layer deposition (ALD) using HfCl4, TEMAHf, TDMAHf and H2O as precursors. The early stages of the ALD were investigated with high-resolution photoelectron spectroscopy and x-ray absorption spectroscopy. We observed the changes occurring in the Si2p, O1s, Hf4f, Hf4d, and Cl2p (for HfCl4 experiment) core level lines after each ALD cycle up to the complete formation of two layers of HfO2. The investigation was carried out in-situ giving the possibility to determine the properties of the grown film after every ALD cycle or even after a half cycle. This work focused on the advantages of the in-situ approach in comparison to ex-situ experiments. The study provides to follow the evolution of the important properties of HfO2: contamination level, density and stoichiometry, and influence of the experimental parameters to the interface layer formation during ALD. Our investigation shows that the in-situ XPS approach for ALD gives much more information than ex-situ experiments.}, language = {en} } @phdthesis{Mueller, author = {M{\"u}ller, Sebastian}, title = {Synchrotron radiation spectroscopy studies of the initial interaction of Chromium and Cobalt with the surface of Titanium Dioxide}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-18914}, abstract = {In the framework of this thesis, synchrotron radiation based spectroscopy methods are applied to study the electronic structures of stoichiometric Rutile single crystals and TiO2 thin films, and the initial stage of chromium and cobalt growth on TiO2 thin films. Resonance photoemission spectroscopy of clean TiO2 at the Ti L2,3 edges led to Auger-like features, with kinetic energies corresponding to the Ti L2,3M4,5M4,5 Auger decay channels. The presence of these features is assigned to origin from a d2L2 charge transfer state. The resonance of the Ti L3M2,3V Auger channel at the Ti L2 edge is assigned to the L2L3V Coster-Kronig Auger, followed by the normal L3M2,3V Auger decay. The deposition of chromium on the TiO2 film causes a strong interaction at the interface, in which TiO(2-x) is formed together with chromium in the Cr 3+ state. Besides the oxidized component, contribution of metallic chromium is found as well. In the ultra-low coverage regime, post-deposition oxidation is observed, in which metallic chromium is oxidized to Cr2O3, accompanied by re-oxidation of the substrate to TiO2. The interface reaction is also reflected by the appearance of two defect states in the band gap. Resonant photo-emission at the Cr 2p and Ti 2p edges shows well distinguishable Cr 3d respectively Ti 3d character of the respective states. Indications for self-cleaning properties are found by removal of surface carbon during storage in UHV, but the influence of chromium on these properties is not studied in detail. The interaction between cobalt and TiO2 is weaker than that of chromium and TiO2. Nevertheless, an interface reaction is found, in which some of the deposited cobalt is oxidized, while the oxide support is partly reduced. The particular oxidation state of Cobalt is identified by means of multiplet calculation including charge transfer and crystal field effects. The calculated XAS and XPS spectra indicate Co 2+ in a tetrahedral coordination with four oxygen atoms. The metallic component of cobalt gives rise to a broad resonance in the valence band down to -20 eV, with a pronounced satellite feature that reflects the oxidized component.}, language = {en} } @phdthesis{Henkel, author = {Henkel, Karsten}, title = {Electrical Investigations on Praseodymium Oxide/Aluminum Oxynitride Containing Metal-Insulator-Semiconductor Stacks and on Metal-Ferroelectric-Insulator-Semiconductor Structures Consisting of Poly[vinylidene fluoride trifluoroethylene]}, publisher = {Shaker}, address = {Aachen}, isbn = {978-3-8322-8404-6}, pages = {165}, abstract = {In this thesis electrical characterizations on metal-insulator-semiconductor (MIS) and metal-ferroelectric-insulator-semiconductor (MFIS) stacks are presented. The results are discussed in terms of the increase of the performance of these stacks in order to optimize the characteristics of devices like the field effect transistor (FET) for logic applications and the ferroelectric field effect transistor (FeFET) for non-volatile and non-destructive readout memory applications. Therefor, two material classes are investigated. Firstly, this work focuses on praseodymium oxide (PrxOy) films as a high-kmaterial on silicon (Si) and silicon carbide in MISsamples. In particular the improvement of the performance by the introduction of an aluminum oxynitride buffer layer, which acts as an interdiffusion barrier and reduces the leakage current, the interface state density and the equivalent oxide thickness, is demonstrated. Secondly, in this work the very attractive ferroelectric material poly[vinylidene fluoride trifluoroethylene] (P[VDF/TrFE]) is introduced in MFIS stacks on Si. The way of successive improvements of the MFIS stack is extensively discussed. Here, the optimization of the preparation of the samples as well as of the layer parameters in the sequence of the MFIS stacks is depicted. An improved long time stability of the memory functionof the MFIS stack with a partially optimized layer sequence is exhibited. The electrical results are correlated to spectroscopic findings on both material systems. Strong interfacial reactions between the PrxOy and Si as well as between the aluminum electrode and the P[VDF/TrFE] layer are observed. For both systems the importance of a buffer layer is discussed and its optimization is addressed, too. On both systems a very nice, as consistent, chain of improvements is shown caused by the spectroscopic controlled preparation combined with electrical measurements in order to obtain the functionality of a given material system.}, language = {en} } @phdthesis{Torche, author = {Torche, Mohamed}, title = {Praseodymium oxide as dielectric in MIS stacks}, address = {Cottbus}, pages = {V, 106}, language = {en} } @phdthesis{Seifarth, author = {Seifarth, Olaf}, title = {Properties of chromium, cobalt and nickel nanoparticles embedded into ordered block copolymers and conducting polymers}, address = {Cottbus}, pages = {166}, language = {en} } @misc{HaeberleHenkelGargourietal., author = {Haeberle, J{\"o}rg and Henkel, Karsten and Gargouri, Hassan and Naumann, Franziska and Gruska, Bernd and Arens, Michael and Tallarida, Massimo and Schmeißer, Dieter}, title = {Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al2O3-films}, series = {Beilstein Journal of Nanotechnology}, volume = {2013}, journal = {Beilstein Journal of Nanotechnology}, number = {4}, issn = {2190-4286}, doi = {10.3762/bjnano.4.83}, pages = {732 -- 742}, abstract = {We report on results on the preparation of thin (<100 nm) aluminum oxide (Al2O3) films on silicon substrates using thermal atomic layer deposition (T-ALD) and plasma enhanced atomic layer deposition (PE-ALD) in the SENTECH SI ALD LL system. The T-ALD Al2O3layers were deposited at 200 °C, for the PE-ALD films we varied the substrate temperature range between room temperature (rt) and 200 °C. We show data from spectroscopic ellipsometry (thickness, refractive index, growth rate) over 4" wafers and correlatethem to X-ray photoelectron spectroscopy (XPS) results. The 200°C T-ALD and PE-ALD processes yield films with similar refractive indices and with oxygen to aluminum elemental ratios very close to the stoichiometric value of 1.5. However, in both also fragments of the precursor are integrated into the film. The PE-ALD films show an increased growth rate and lower carbon contaminations. Reducing the deposition temperature down to rt leads to a higher content of carbon and CH-species. We also find a decrease of the refractive index and of the oxygen to aluminum elemental ratio as well as an increase of the growth rate whereas the homogeneity of the film growth is not influenced significantly. Initial state energy shifts in all PE-ALD samples are observed which we attribute to a net negative charge within the films.}, language = {en} } @inproceedings{CuypersDorpTallaridaetal., author = {Cuypers, Daniel and Dorp, Dennis H. von and Tallarida, Massimo and Brizzi, Simone and Rodriguez, Leonard and Conard, Thierry and Arnauts, Sophia and Schmeißer, Dieter and Adelmann, Christoph and De Gendt, Stefan}, title = {Study of InP Surfaces After Wet Chemical Treatments}, series = {Meeting Abstracts-Electrochemical Society, San Francisco, 2013}, booktitle = {Meeting Abstracts-Electrochemical Society, San Francisco, 2013}, publisher = {The Electrochemical Society}, pages = {S. 2132}, language = {en} } @misc{CuypersDorpTallaridaetal., author = {Cuypers, Daniel and Dorp, Dennis H. von and Tallarida, Massimo and Brizzi, Simone and Rodriguez, Leonard and Conard, Thierry and Arnauts, Sophia and Schmeißer, Dieter and Adelmann, Christoph and De Gendt, Stefan}, title = {Study of InP Surfaces after Wet Chemical Treatments}, series = {ECS Transactions}, volume = {58}, journal = {ECS Transactions}, number = {6}, issn = {1938-6737}, doi = {10.1149/05806.0297ecst}, pages = {297 -- 303}, abstract = {In this work synchrotron radiation photoemission spectroscopy (SRPES) is used to study InP surfaces after different wet chemical treatments. All results are compared to a typical fingerprint of surface components present on an as received InP sample. It is shown that acidified (HCl and H₂SO₄) treatments efficiently remove the native phosphate, although components like Pᴼ, Inᴼ and P(2±∆)+ remain present. In alkaline solution (NH₄OH) oxide remains present at the surface. As an alternative treatment, the immersion into (NH₄)₂S was studied. This passivation treatment results in fewer surface components which suggests that a higher quality surface is obtained.}, language = {en} } @misc{CuypersDorpTallaridaetal., author = {Cuypers, Daniel and Dorp, Dennis H. von and Tallarida, Massimo and Brizzi, Simone and Conard, Thierry and Rodriguez, Leonard and Mees, M. and Arnauts, Sophia and Schmeißer, Dieter and Adelmann, Christoph and De Gendt, Stefan}, title = {Study of InP Surfaces after Wet Chemical Treatments}, series = {ECS Journal of Solid State Science and Technology}, volume = {3}, journal = {ECS Journal of Solid State Science and Technology}, number = {1}, issn = {2162-8777}, doi = {10.1149/2.005401jss}, pages = {N3016 -- N3022}, abstract = {The influence of different wet chemical treatments (HCl, H₂SO₄, NH₄OH) on the composition of InP surfaces is studied by using synchrotron radiation photoemission spectroscopy (SRPES). It is shown that a significant amount of oxide remains present after immersion in a NH₄OH solution which is ascribed to the insolubility of In³⁺ at higher pH values. Acidic treatments efficiently remove the native oxide, although components like Pᴼ, Inᴼ and P(2±Δ)+ suboxides are observed. Alternatively, the influence of a passivation step in (NH₄)₂S solution on the surface composition was investigated. The InP surface after immersion into (NH₄)₂S results in fewer surface components, without detection of Pᴼ and P(2±Δ)+ suboxides. Finally, slight etching of InP surfaces in HCl/H₂O₂ solution followed by a native oxide removal step, showed no significant effect on the surface composition.}, language = {en} } @misc{MuellerStaedterRachowetal., author = {M{\"u}ller, Klaus and St{\"a}dter, Matthias and Rachow, Fabian and Hoffmannbeck, David and Schmeißer, Dieter}, title = {Sabatier-based CO2-methanation by catalytic conversion}, series = {Environmental Earth Sciences}, volume = {70}, journal = {Environmental Earth Sciences}, number = {8}, issn = {1866-6280}, doi = {10.1007/s12665-013-2609-3}, pages = {3771 -- 3778}, abstract = {The catalytic conversion of CO2is an important component for the reintegration of secondary products like CO2 or H2 into the energy supply. An example is the "power to gas'" concept with a conversion of CO2 into CH4. The CO2 is transferred into a carrier of chemical energy, with the possibility to feed the produced CH4 into the existing network of natural gas. At temperatures of around 350 °C, hydrogenation of CO2 to CH4 is possible by the Sabatier reaction CO2+4H2->CH4+H2O. One prerequisite for efficient kinetics of the Sabatier reaction is the application and optimization of catalysts. The focus of catalyst development is given to their performance under the conditions to be expected in the special application. As a part of the project Geoenergy-Research (GeoEn), we address questions related to the catalytic utilization of CO2 produced in the course of the oxyfuel combustion of lignite. In this contribution, we report on the experimental setup in laboratory scale, which enables an advanced characterization of the catalytic performance, including thermodesorption measurements at atmospheric pressure in order to determine the amount of adsorbed CO2 under real conditions. We also show data for activation energies, the catalytic performance as function of temperature and the long time stability of a commercial Ru-based catalyst.}, language = {en} } @misc{DasTallaridaSchmeisser, author = {Das, Chittaranjan and Tallarida, Massimo and Schmeißer, Dieter}, title = {Linear dichroism in ALD layers of TiO₂}, series = {Environmental Earth Sciences}, volume = {70}, journal = {Environmental Earth Sciences}, number = {8}, issn = {1866-6280}, doi = {10.1007/s12665-013-2836-7}, pages = {3785 -- 3795}, abstract = {We prepare TiO₂film by ALD and study their electronic properties by soft X-ray absorption spectroscopy (XAS) and photoelectron spectroscopy. We focus on XAS and X-ray linear dichroism to indentify band onset and learn about local distortion of the Ti-O octahedral atomic and about defects which cause Ti-based electronic states within the band gap.}, language = {en} } @misc{StaedterMuellerRachowetal., author = {St{\"a}dter, Matthias and M{\"u}ller, Klaus and Rachow, Fabian and Richter, Matthias and Schmeißer, Dieter}, title = {Ambient pressure thermal desorption spectroscopy (AP-TDS) of NiO/SiO2 catalysts}, series = {Environmental Earth Sciences}, volume = {70}, journal = {Environmental Earth Sciences}, number = {8}, issn = {1866-6280}, doi = {10.1007/s12665-013-2835-8}, pages = {3779 -- 3784}, abstract = {The Sabatier reaction is a key process in the "power-to-gas" application which is considered to con-tribute to future chemical energy storage systems. In this contribution we focus on the catalytic active sites of a NiO catalyst supported on SiO2(NiO/SiO2) which is commonly used in the Sabatier reaction. A novel technique for the characterization of the active sites is presented and dis-cussed using thermal desorption spectroscopy at ambient pressure. This analytical tool is operated under reaction conditions and allows element specific measurements during the catalytic process of CO2 reforming towards methane. Beside the desorption experiments, XPS and XAS measurements of pristine and catalytically used samples are performed to determine the influence of the Sabatier reaction conditions on the surface structure of the catalyst.}, language = {en} } @misc{ScheckWenderothSchmeisserMuttietal., author = {Scheck-Wenderoth, Magdalena and Schmeißer, Dieter and Mutti, Maria and Kolditz, Olaf and Huenges, Ernst and Schultz, Hans-Martin and Liebscher, Axel and Bock, Michaela}, title = {Geoenergy: new concepts for utilization of geo-reservoirs as potential energy sources}, series = {Environmental Earth Sciences}, volume = {70}, journal = {Environmental Earth Sciences}, number = {8}, issn = {1866-6280}, doi = {10.1007/s12665-013-2877-y}, pages = {3427 -- 3431}, language = {en} } @misc{GerlichOhsiekKleinetal., author = {Gerlich, Lukas and Ohsiek, Susanne and Klein, Christoph and Geiß, Mario and Friedemann, Michael and K{\"u}cher, Peter and Schmeißer, Dieter}, title = {Interface engineering for the TaN/Ta barrier film deposition process to control Ta-crystal growth}, series = {Microelectronic Engineering}, volume = {Vol. 106}, journal = {Microelectronic Engineering}, doi = {10.1016/j.mee.2013.01.017}, pages = {63 -- 68}, abstract = {As a consequence of device shrinking the resistivity of the widely used TaN/Ta double barrier layer becomes an increasingly important parameter for device speed beyond the 32 nm technology node. In this study we describe the optimization of the deposition of TaN/Ta stacks in such a way that tantalum nitride layer thickness is minimized and tantalum grows in the favorable conducting alpha-phase. In the first part of the study we usedin situ ARXPS to investigate the growth of different tantalum nitride layers on SiO2 and SiOCH as a function of deposition time, nitrogen flow and deposition power. In the second part we analyzed the crystalline phase of a 20 nm thick tantalum layer deposited on top of the same series of tantalum nitride layers characterized in the growth study. The main findings are the appearance of tan-talum carbide and tantalum silicide as interface species for the deposition on SiOCH and only tantalum silicide for the deposition on SiO2. We found that alpha-tantalum grows preferably on tantalum carbide and nitrogen rich intermediate layers whereas silicide at the interface promotes the growth of beta-tantalum. To verify these findings we studied two additional modifications of the interface. A lower bias power for a deposition of tantalum nitride on SiO2 was used to confirm the role of tantalum silicide and a thermal treatment of a thin tantalum layer on SiOCH was applied to confirm the role of tantalum carbide. Finally, the contact resistance in via chains on patterned wafers for four selected processes showed the same trends as the sheet resistance of the corresponding barrier films on blanket wafer experiments.}, language = {en} } @misc{HenkelGargouriGruskaetal., author = {Henkel, Karsten and Gargouri, Hassan and Gruska, Bernd and Arens, Michael and Tallarida, Massimo and Schmeißer, Dieter}, title = {Capacitance and conductance versus voltage characterization of Al2O3 layers prepared by PE-ALD at 25°C ≤ T ≤ 200°C}, series = {Journal of Vacuum Science and Technology A}, volume = {1}, journal = {Journal of Vacuum Science and Technology A}, number = {32}, doi = {10.1116/1.4831897}, pages = {01A107-1 -- 01A107-10}, abstract = {In this work, plasma enhanced atomic layer deposited (PE-ALD) samples were prepared at substrate temperatures in the range between room temperature (RT) and 200 °C and investigated by capacitance-voltage and conductance-voltage recordings. The measurements are compared to standard thermal atomic layer deposition (T-ALD) at 200 °C. Very low interface state density (D it) ~1011 eV-1 cm-2 could be achieved for the PE-ALD process at 200 °C substrate temperature after postdeposition anneal (PDA) in forming gas at 450 °C. The PDA works very effectively for both the PE-ALD and T-ALD at 200 °C substrate temperature delivering also similar values of negative fixed charge density (N fix) around -2.5 × 1012 cm-2. At the substrate temperature of 150 °C, highest N fix (-2.9 × 1012 cm-2) and moderate D it (2.7 × 1011 eV-1 cm-2) values were observed. The as deposited PE-ALD layer at RT shows both low D it in the range of (1 to 3) × 1011 eV-1 cm-2 and low N fix (-4.4 × 1011 cm-2) at the same time. The dependencies of N fix, D it, and relative permittivity on the substrate temperatures and its adjustability are discussed.}, language = {en} } @phdthesis{Hoffmann, author = {Hoffmann, Patrick}, title = {Untersuchungen zu Inhomogenit{\"a}ten an der Halbleitergrenzfl{\"a}che Silizium-Siliziumoxynitrid}, publisher = {Shaker-Verlag}, address = {Aachen}, isbn = {3-8322-1982-X}, pages = {179}, language = {de} } @phdthesis{Mikalo, author = {Mikalo, Ricardo Pablo}, title = {Elektronische Eigenschaften von leitf{\"a}higen konjugierten Polymeren und deren Grenzfl{\"a}chenreaktionen im elektrischen Kontakt mit Metallen}, publisher = {Der Andere Verlag}, address = {Osnarbr{\"u}ck}, isbn = {3-89959-115-1}, pages = {310, XIII}, language = {de} } @phdthesis{Heller, author = {Heller, Thomas}, title = {Molekulare Resonanzen im Wirkungsquerschnitt der Photoemission in den Valenzzust{\"a}nden der st{\"o}chiometrischen und der mit Natrium belegten WO3 und TiO2 (110) 1x1 Oberfl{\"a}che}, publisher = {Shaker}, address = {Aachen}, isbn = {3-8322-0742-2}, pages = {157}, language = {de} } @phdthesis{Yfantis, author = {Yfantis, Alexandros D.}, title = {Development and Characterisation of Corrosion Resistent Layers of Conducting Polymers on Aluminium Alloys}, publisher = {Parissianou}, address = {Athen}, isbn = {960-394-115-8}, pages = {XI, 103}, language = {en} } @phdthesis{Appel, author = {Appel, G{\"u}nter}, title = {Untersuchungen zur mesoskopischen und elektronischen Struktur von Polypyrroltosylat und Polypyrrolkupferphthalocyaninsulfonat}, publisher = {Shaker}, address = {Aachen}, isbn = {3-8265-4830-2}, pages = {118}, language = {de} } @phdthesis{Hofmann, author = {Hofmann, Andreas}, title = {Elektronische Struktur epitaktischer Chalkopyrite und deren Heterokontakte f{\"u}r die Photovoltaik}, address = {Cottbus}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-24434}, pages = {194}, language = {de} } @phdthesis{Zimmer, author = {Zimmer, Fabian}, title = {Herstellung und Charakterisierung hocheffzienter, mikromechanischer NIR-Beugungsgitter f{\"u}r den Einsatz in miniaturisierten Spektrometern}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-25224}, pages = {XVI, 127}, language = {de} } @phdthesis{Dudek, author = {Dudek, Piotr T.}, title = {Atomic scale engineering of HfO2-based dielectrics for future DRAM applications}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-22775}, pages = {106}, abstract = {Modern dielectrics in combination with appropriate metal electrodes have a great potential to solve many difficulties associated with continuing miniaturization process in the microelectronic industry. One significant branch of microelectronics incorporates dynamic random access memory (DRAM) market. The DRAM devices scaled for over 35 years starting from 4 kb density to several Gb nowadays. The scaling process led to the dielectric material thickness reduction, resulting in higher leakage current density, and as a consequence higher power consumption. As a possible solution for this problem, alternative dielectric materials with improved electrical and material science parameters were intensively studied by many research groups. The higher dielectric constant allows the use of physically thicker layers with high capacitance but strongly reduced leakage current density. This work focused on deposition and characterization of thin insulating layers. The material engineering process was based on Si cleanroom compatible HfO2 thin films deposited on TiN metal electrodes. A combined materials science and dielectric characterization study showed that Ba added HfO2 (BaHfO3) films and Ti added BaHfO3 (BaHf0.5Ti0.5O3) layers are promising candidates for future generation of state of the art DRAMs. In especial a strong increase of the dielectric permittivity k was achieved for thin films of cubic BaHfO3 (k~38) and BaHf0.5Ti0.5O3 (k~90) with respect to monoclinic HfO2 (k~19). Meanwhile the CET values scaled down to 1 nm for BaHfO3 and ~0.8 nm for BaHf0.5Ti0.5O3 with respect to HfO2 (CET=1.5 nm). The Hf4+ ions substitution in BaHfO3 by Ti4+ ions led to a significant decrease of thermal budget from 900°C for BaHfO3 to 700°C for BaHf0.5Ti0.5O3. Future studies need to focus on the use of appropriate metal electrodes (high work function) and on film deposition process (homogeneity) for better current leakage control.}, language = {en} } @phdthesis{Rauscher, author = {Rauscher, Stefan}, title = {Dynamische Modifizierung von Silizium-Elektrolyt-Grenzfl{\"a}chen und deren oberfl{\"a}chenphysikalischen Eigenschaften}, publisher = {Brandenburgische Techn. Univ.}, address = {Cottbus}, pages = {185}, language = {de} } @misc{RichterStarkeSchmeisser, author = {Richter, Matthias and Starke, Ulrich and Schmeißer, Dieter}, title = {Multiple Auger processes in Graphene}, series = {Journal of Electron Spectroscopy and Related Phenomena}, journal = {Journal of Electron Spectroscopy and Related Phenomena}, number = {Vol. 192}, issn = {0368-2048}, doi = {10.1016/j.elspec.2013.12.009}, pages = {1 -- 6}, abstract = {Resonant Auger decay processes have been studied by resonant photoemission spectroscopy (resPES) and X-ray absorption spectroscopy (XAS) in Graphene systems. The pi*-resonance is used to identify the degree of localization of the lowest pi*-orbitals in the conduction band. Localization and lifetime of the photo-excited intermediate state cause the formation of multiple Auger processes. For the Graphene systems we identify two novel Auger decay combinations with a four hole final state: the (S+S) and the(S+S)* decay. We demonstrate that these processes are sensitive for interlayer coupling and interactions with the metallic free electrons of the substrate.}, language = {en} } @misc{TallaridaDasSchmeisser, author = {Tallarida, Massimo and Das, Chittaranjan and Schmeißer, Dieter}, title = {Quantum size effects in TiO2 thin films grown by atomic layer deposition}, series = {Beilstein Journal of Nanotechnology}, journal = {Beilstein Journal of Nanotechnology}, number = {5}, issn = {2190-4286}, doi = {10.3762/bjnano.5.7}, pages = {77 -- 82}, abstract = {We study the atomic layer deposition of TiO2 by means of X-ray absorption spectroscopy. The Ti precursor, titanium isopropoxide, was used in combination with H2O on Si/SiO2 substrates that were heated at 200 °C. The low growth rate (0.15 {\AA}/cycle) and the in situ characterization permitted to follow changes in the electronic structure of TiO2 in the sub-nanometer range, which are influenced by quantum size effects. The modified electronic properties may play an important role in charge carrier transport and separation, and increase the efficiency of energy conversion systems.}, language = {en} } @misc{RichterFriedrichSchmeisser, author = {Richter, Matthias and Friedrich, Daniel and Schmeißer, Dieter}, title = {Interlayer-exciton mediated three-hole-Auger-decay in the pi-band of highly oriented pyrolytic graphite}, series = {Physica E}, volume = {Vol. 56}, journal = {Physica E}, issn = {1386-9477}, doi = {10.1016/j.physe.2013.01.015}, pages = {441 -- 446}, abstract = {Resonant photoemission spectroscopy(resPES) is used to probe the occupied pi- and unoccupied pi*-bands of carbon thin films with particular focus on the Auger decay. Highly Oriented Pyrolytic Graphite (HOPG) is studied at the C1s edge. We find strong resonant features at 285.5 eV and 292 eV in the resPES diagram. The normal two-hole Auger decay proceeds under constant kinetic energy (451)only in the sigma*-region. In the pi*-region, however, it proceeds under 67.5° in terms of a Ebind(w) diagram. We attribute this to a multiple Auger decay with a net three hole final state. For this novel decay process we propose a model.We discuss the long lifetime of the first resonant excitation and conclude that it arises from the strong excitonic character of the first resonant state. We use HOPG as a reference system and suggest that this novel process is a tool to identify interlayer-substrate interaction of the carbon layers involved.}, language = {en} } @phdthesis{Michling, author = {Michling, Marcel Frank}, title = {Spektroskopische Untersuchungen an organischen Materialien und Metalloxiden}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-29014}, pages = {181}, abstract = {Im Rahmen der vorliegenden Arbeit wurde mit Synchrotron-basierenden, optischen und Elektronen-basierenden Methoden die elektronischen Eigenschaften zweier unterschiedlicher Materialklassen untersucht. Der Fokus lag dabei im besonderen auf der Bestimmung der Gr{\"o}ße der Bandl{\"u}cke/HOMO-LUMO-L{\"u}cke und ihre Abh{\"a}ngigkeit der verwendeten Methode. Die zwei unterschiedliche Materialklassen, welche untersucht wurden sind folgende: Erstens die organischen Systeme Cobalt-Phthalocyanin und Fulleren. An Ihnen wird der Einfluss der verwendeten Messmethoden aufgezeigt und die sich draus ergebenen HOMO- LUMO-L{\"u}cken (elektronisch, Volumen, Oberfl{\"a}che, optisch) diskutiert. Es zeigt sich, dass die optische Methode (Ellipsometrie) generell den kleinsten Wert und die elektronischen Methoden (XPS, XAS) den gr{\"o}ßten Wert ergeben. Die Gr{\"u}nde daf{\"u}r werden ausf{\"u}hrlich diskutiert. Durch die Kombination von XPS- , XAS- und Ellipsometrie-Messungen war es m{\"o}glich die Orientierung der aufgedampften CoPc-Molek{\"u}le auf den SiO2-Substrat zu bestimmen. Zweitens wurden die Metalloxide HfO2, Al2O3, In2O3 und Ga2O3 aufgrund ihrer großen technologischen Bedeutung untersucht. Mit Hilfe von ALD Zyklus-f{\"u}r-Zyklus Experimenten konnten die elektronischen Eigenschaften von HfO2 in Abh{\"a}ngigkeit der ALD- Zyklenzahl und das Wachstum von HfO2 in den ersten Zyklen studiert werden. Auf Basis der XPS- und EELS-Ergebnisse wurde ein Wachstumsmodell entwickelt. Es wird ebenfalls der Einfluss einer Dipolschicht an der Grenzfläche HfO2/SiO2 auf die Gr{\"o}ße der Bandl{\"u}cke in den EELS-Messungen diskutiert. Mittels resonanten Photoemission wurde ein neuer Auger-Mechanismus (3-Loch-Auger-Prozess) in den Oxiden gefunden. Dieser hat seine Ursache in Defekten. Defekte f{\"u}hren auch zu einer Fano-Anti-Resonanz, welche an der O1s-Absorptions-Kante beobachtet und diskutiert wird.}, language = {de} } @phdthesis{Richter, author = {Richter, Matthias}, title = {Excitons and Polarons in resonant Auger decay processes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-29816}, pages = {169}, abstract = {In the framework of this thesis synchrotron radiation spectroscopy is applied to study the electronic structure of organic semiconductors, of Graphene, and of transition metal (TM) oxide water splitting catalysts (Co-PI) with emphasis on excitonic and polaronic effects. For a correct theoretical description of the electronic structure of these material classes electron-phonon and electron-electron coupling as well as polarization and excitonic effects have to be considered. Excitons and Polarons are localized in-gap states. They are known to affect the optical properties of the material. Their influence can also be revealed in the resonant Auger decay profile. Even in TM-oxides Polarons and Excitons are observed as a consequence of an oxygen 2p to TM3d charge transfer. Therefor, the following three material classes are chosen for the fundamental study of Excitons and Polarons in resonant Auger decay processes. First, the existence of localized polaronic and excitonic states is investigated for regioregular-Poly(3 hexylthiophene-2,5-diyl) (rr-P3HT) and Phenyl-C61-butyric acid methyl ester (PCBM) used as a light absorber in organic solar cells. The existence of 2D-Polarons, singlet Exciton, and triplet Exciton is demonstrated for rr-P3HT whereas for PCBM only singlet Excitons are observed. Singlet Excitons show an influence on the resonant Auger decay by a combined spectator-participator (S+P) Auger decay in the π*-band. Second, for a more detailed study of the (S+P) decay Highly Ordered Pyrolytic Graphite (HOPG) is chosen. For Graphene as a single layer of HOPG without van der Waals force another combination of Auger decays can be observed: a double spectator Auger (S+S) and a double spectator Auger-Gain (S+S)* decay. Third, Co-PI (cobalt oxide compound) is investigated. It is a TM-oxide catalyst used for the oxygen evolution reaction in photo-electrochemical cells. Self-trapped Excitons formed by resonant core electron excitation into self-trapped hole states give rise to a combined Auger decay process (S+P). For all three novel Auger decay processes {(S+P), (S+S), and (S+S)*} a model is proposed.}, language = {en} } @misc{HaeberleRichterGalazkaetal., author = {Haeberle, J{\"o}rg and Richter, Matthias and Galazka, Zbigniew and Janowitz, Christoph and Schmeißer, Dieter}, title = {Resonant Photoemission at the O1s threshold to characterize In2O3 single crystals}, series = {Thin Solid Films}, volume = {2014}, journal = {Thin Solid Films}, number = {555}, issn = {0040-6090}, doi = {10.1016/j.tsf.2013.03.036}, pages = {53 -- 56}, abstract = {We report on spectroscopic investigations on In2O3 single crystals. We focus on the detailed analysis of the O1s resonance profile by resonant photoelectron spectroscopy. We analyze the electronic structure and assign the O2p to build the valence band and both, O2p and In5s5p states to contribute to the conduction band (CB). We determine the partial density of states for the valence and CBs and find a strong hybridization of O2p and In5s states. This is deduced from constant final state spectra on the O-KLL-Auger over the O K-edge and In M4,5-edge and a comparison to the corresponding X-ray absorption spectroscopy data.We also identify several types of defects. A broad band of oxygen derived defects is identified that extends throughout the gap. These are attributed to small polarons which cause an anti-resonance in the valence states around the O1s threshold. In addition, a separate Auger decay at resonance indicates the existence of localized charge transfer states which involves localized In5s5p states.}, language = {en} } @misc{KrammHerrmannGeppertFiechteretal., author = {Kramm, Ulrike Ingrid and Herrmann-Geppert, Iris and Fiechter, Sebastian and Zehl, Gerald and Zizak, Ivo and Dorbandt, Iris and Schmeißer, Dieter and Bogdanoff, Peter}, title = {Effect of iron carbide formation on the number of active sites in Fe-N-C catalysts for the oxygen reduction reaction in acidic media}, series = {Journals of materials chemistry A}, journal = {Journals of materials chemistry A}, number = {8}, issn = {2050-7488}, doi = {10.1039/c3ta13821f}, pages = {2663 -- 2670}, language = {en} } @misc{KrammLefevreLaroucheetal., author = {Kramm, Ulrike Ingrid and Lef{\`e}vre, Michel and Larouche, Nicholas and Schmeißer, Dieter and Dodelet, Jean-Pol}, title = {Correlations between Mass Activity and Physicochemical Properties of Fe/N/C Catalysts for the ORR in PEM Fuel Cell via 57 Fe M{\"o}ssbauer Spectroscopy and Other Techniques}, series = {Journal of the American Chemica Society}, volume = {136}, journal = {Journal of the American Chemica Society}, number = {3}, issn = {0002-7863}, doi = {10.1021/ja410076f}, pages = {978 -- 985}, abstract = {The aim of this work is to clarify the origin of the enhanced PEM-FC performance of catalysts prepared by the procedures described in Science 2009, 324, 71 and Nat. Commun. 2011, 2, 416. Catalysts were characterized after a first heat treatment in argon at 1050 °C (Ar) and a second heat treatment in ammonia at 950 °C (Ar + NH3). For the NC catalysts a variation of the nitrogen precursor was also implemented. 57Fe M{\"o}ssbauer spectroscopy, X-ray photoelectron spectroscopy, neutron activation analysis, and N2 sorption measurements were used to characterize all catalysts. The results were correlated to the mass activity of these catalysts measured at 0.8 V in H2/O2 PEM-FC. It was found that all catalysts contain the same FeN4-like species already found in INRS Standard (Phys. Chem. Chem. Phys. 2012, 14, 11673). Among all FeN4-like species, only D1 sites, assigned to FeN4/C, and D3, assigned to N-FeN2+2 /C sites, were active for the oxygen reduction reaction (ORR). The difference between INRS Standard and the new catalysts is simply that there are many more D1 and D3 sites available in the new catalysts. All (Ar + NH3)-type catalysts have a much larger porosity than Ar-type catalysts, while the maximum number of their active sites is only slightly larger after a second heat treatment in NH3. The large difference in activity between the Ar-type catalysts and the Ar + NH3 ones stems from the availability of the sites to perform ORR, as many sites of the Ar-type catalysts are secluded in the material, while they are available at the surface of the Ar + NH3-type catalysts.}, language = {en} } @phdthesis{Gerlich, author = {Gerlich, Lukas}, title = {In situ ARXPS Charakterisierung von tantalbasierten Barriereschichten}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-28485}, pages = {136}, abstract = {Als eine Folge der Miniaturisierung aller integrierten elektrischen Bauteile wird der spezifische Widerstand der TaN/Ta Doppelsperrschichten ein zunehmend wichtiger Parameter f{\"u}r die Schaltgeschwindigkeit beim 32 nm Technologieknoten. In Rahmen dieser Arbeit wird die Optimierung der Abscheidung von TaN/Ta Stapeln durchgef{\"u}hrt, mit dem Ziel die Tantalnitridschichtdicke zu minimieren und das Tantal in der leitf{\"a}higeren alpha-Phase wachsen zu lassen. Im ersten Teil der Studie wurde in situ ARXPS verwendet, um das Wachstum von verschiedenen Tantalnitridschichten auf SiO2 und SiCOH in Abh{\"a}ngigkeit der Abscheidezeit, des Stickstoffflusses und der Abscheideleistung zu untersuchen. Im zweiten Teil wurde die kristalline Phase 20 nm dicken Tantal Schichten abgeschieden auf verschiedenen Tantalnitridschichten, die in der Wachstumsstudie vorgestellt worden sind, untersucht. Die wichtigsten Erkenntnisse sind das Auftreten von Tantalkarbid und Tantalsilizid als Zwischenschichtverbindungen bei der Abscheidung auf SiCOH und nur Tantalsilizid f{\"u}r die Abscheidung auf SiO2. Demzufolge w{\"a}chst alpha-Tantal vorzugsweise auf Tantalkarbid und stickstoffreichen Zwischenschichten, w{\"a}hrend Silizid an der Schnittstelle das Wachstum von beta-Tantal f{\"o}rdert. Um die Ergebnisse zu {\"u}berpr{\"u}fen, wurden zwei weitere Modifikationen des Interfaces untersucht. So wurde eine kleinere Bias-Leistung f{\"u}r eine Abscheidung von Tantalnitrid auf SiO2 benutzt, um die Rolle des Tantalsilizids zu best{\"a}tigen. Außerdem wurde eine thermische Behandlung einer d{\"u}nnen Tantalschicht auf SiCOH durchgef{\"u}hrt, um die Rolle des Tantalkarbids zu best{\"a}tigen. Schließlich ergab die Kontaktwiderstandsmessung in Viaketten auf strukturierten Wafern f{\"u}r vier ausgew{\"a}hlte Prozesse tendenziell den gleichen Verlauf wie die Schichtwiderstandsergebnisse der entsprechenden Barrierenaufbauten der Experimente auf blanken Testwafern.}, language = {de} } @misc{AdelmannSchramChewetal., author = {Adelmann, Christoph and Schram, Tom and Chew, Soon Aik and Woicik, J. C. and Brizzi, Simone and Tallarida, Massimo and Schmeißer, Dieter and Horiguchi, Naoto and Elshocht, Sven van and Ragnarsson, Lars-{\AA}ke}, title = {On the scalability of doped hafnia thin films}, series = {Applied Physics Letters}, journal = {Applied Physics Letters}, number = {104}, issn = {0003-6951}, doi = {10.1063/1.4870075}, pages = {122906-1 -- 122906-4}, abstract = {The scaling behavior of Gd- and Al-doped HfO2 films as gate dielectrics in metal-oxide-semiconductor (MOS) capacitors was studied. For equivalent oxide thicknesses (EOTs) in the range of 10 {\AA}, crystallized Gd:HfO2 showed higher leakage current densities than crystallized Al:HfO2, with undoped HfO2 in between. Ultimately, the scalability of Al:HfO2 was limited by the ability to crystallize the films at a given thermal budget. As a result, for post-deposition annealing at 800 °C, the EOT of Al:HfO2 based MOS capacitors was limited to ∼8 {\AA}. However, for such an EOT, leakage current densities were reduced by about 100× with respect to HfO2. This demonstrates the high potential of Al:HfO2 for low-standby-power MOS devices.}, language = {en} } @inproceedings{HenkelTallaridaHaeberleetal., author = {Henkel, Karsten and Tallarida, Massimo and Haeberle, J{\"o}rg and Gargouri, Hassan and Naumann, Franziska and Gruska, Bernd and Arens, Michael and Schmeißer, Dieter}, title = {PE-ALD-Al2O3-Schichten f{\"u}r die Passivierung von Solarzellen}, series = {Tagungsband Photovoltaik-Meeting: Anwendungen-Qualit{\"a}t-Perspektiven, Senftenberg, 16.04.2014}, booktitle = {Tagungsband Photovoltaik-Meeting: Anwendungen-Qualit{\"a}t-Perspektiven, Senftenberg, 16.04.2014}, editor = {Gl{\"u}ck, Bernhard K. and Schmidt, Sindy and Stein, Erhard and Raschke, J{\"o}rg-Uwe and Richter, Hans}, publisher = {Cottbus-Senftenberg}, address = {BTU}, pages = {7 -- 14}, abstract = {D{\"u}nne Al2O3-Schichten wurden bei Substrattemperaturen zwischen Raumtemperatur und 200°C mittels PE-ALD auf Si-Substraten abgeschieden und ellipsometrisch, spektroskopisch und elektrisch charakterisiert. Ihr Potenzial f{\"u}r die chemische und Feldeffektpassivierung der Oberfl{\"a}chenrekombination wird bewertet.}, language = {de} } @misc{MandalHenkelSchmeisser, author = {Mandal, Dipankar and Henkel, Karsten and Schmeißer, Dieter}, title = {Improved performance of a polymer nanogenerator based on silver nanoparticles doped electrospun P(VDF-HFP) nanofibers}, series = {Physical Chemistry Chemical Physics}, volume = {2014}, journal = {Physical Chemistry Chemical Physics}, number = {16}, issn = {1463-9084}, doi = {10.1039/C3CP55238A}, pages = {10403 -- 10407}, abstract = {We report on the electrospinning of poly(vinylidene fluoride-hexafluoropropylene) [P(VDF-HFP)] nanofibers doped with silver nanoparticles for the preparation of a polymer based nanogenerator (PNG). It has been found that the yield of the piezoelectric phase is increased by the addition of silver nanoparticles. Furthermore, defects in the P(VDF-HFP) electrospun fibers are removed resulting in a significant enhancement in the output power of the PNG. A maximum generated PNG output voltage of 3 V with a current density of 0.9 μA cm-2 is achieved.}, language = {en} } @misc{SchmeisserHaeberleBarquinhaetal., author = {Schmeißer, Dieter and Haeberle, J{\"o}rg and Barquinha, Pedro and Gaspar, Diana and Pereira, Lu{\´i}s and Martins, Rodrigo and Fortunato, Elvira}, title = {Electronic structure of amorphous ZnO films}, series = {Physica Status Solidi C}, volume = {11}, journal = {Physica Status Solidi C}, number = {9-10}, issn = {1610-1642}, doi = {10.1002/pssc.201400010}, pages = {1476 -- 1480}, abstract = {We use resonant photoemission spectroscopy (resPES) to study the electronic properties of amorphous ZnO (a-ZnO) layers. We report on the core levels, the valence band (VB) PES data, and the X-ray absorption (XAS) data which we use for the conduction band (CB) density of states. From these results we are able to derive the partial density of states (pDOS) of O2p and Zn4s4p states in the VB and CB, respectively as well as a band scheme. At the O1s resonance we observe a band of localized defect states which is located between the Fermi energy and the CBM. At the Zn2p edge the XAS data indicate that localized Zn4s4p states are involved in the DOS starting already at the Fermi energy.}, language = {en} } @misc{TallaridaDasCibrevetal., author = {Tallarida, Massimo and Das, Chittaranjan and Cibrev, Dejan and Kukli, Kaupo and Tamm, Aile and Ritala, Mikko and Lana-Villarreal, Teresa and Gómez, Roberto and Leskel{\"a}, Markku and Schmeißer, Dieter}, title = {Modification of Hematite Electronic Properties with Trimethyl Aluminum to Enhance the Efficiency of Photoelectrodes}, series = {The Journal of Physical Chemistry Letters}, volume = {5}, journal = {The Journal of Physical Chemistry Letters}, number = {20}, doi = {10.1021/jz501751w}, pages = {3582 -- 3587}, abstract = {The electronic properties of hematite were investigated by means of synchrotron radiation photoemission (SR-PES) and X-ray absorption spectroscopy (XAS). Hematite samples were exposed to trimethyl aluminum (TMA) pulses, a widely used Al-precursor for the atomic layer deposition (ALD) of Al2O3. SR-PES and XAS showed that the electronic properties of hematite were modified by the interaction with TMA. In particular, the hybridization of O 2p states with Fe 3d and Fe 4s4p changed upon TMA pulses due to electron inclusion as polarons. The change of hybridization correlates with an enhancement of the photocurrent density due to water oxidation for the hematite electrodes. Such an enhancement has been associated with an improvement in charge carrier transport. Our findings open new perspectives for the understanding and utilization of electrode modifications by very thin ALD films and show that the interactions between metal precursors and substrates seem to be important factors in defining their electronic and photoelectrocatalytic properties.}, language = {en} } @misc{KrammLefevreBogdanoffetal., author = {Kramm, Ulrike Ingrid and Lef{\`e}vre, Michel and Bogdanoff, Peter and Schmeißer, Dieter and Dodelet, Jean-Pol}, title = {Analyzing Structural Changes of Fe-N-C Cathode Catalysts in PEM Fuel Cell by M{\"o}ßbauer Spectroscopy of Complete Membrane-Electrode-Assemblies}, series = {The Journal of Physical Chemistry Letters}, volume = {2014}, journal = {The Journal of Physical Chemistry Letters}, number = {5}, issn = {1948-7185}, doi = {10.1021/jz501955g}, pages = {3750 -- 3756}, abstract = {The applicability of analyzing by M{\"o}ßbauer spectroscopy the structural changes of Fe-N-C catalysts that have been tested at the cathode of membrane electrode assemblies in proton exchange membrane (PEM) fuel cells is demonstrated. The M{\"o}ßbauer characterization of powders of the same catalysts was recently described in our previous publication. A possible change of the iron species upon testing in fuel cell was investigated here by M{\"o}ßbauer spectroscopy, energy-dispersive X-ray cross-sectional imaging, and neutron activation analysis. Our results show that the absorption probability of γ rays by the iron nuclei in Fe-N-C is strongly affected by the presence of Nafion and water content. A detailed investigation of the effect of an oxidizing treatment (1.2 V) of the non-noble cathode in PEM fuel cell indicates that the observed activity decay is mainly attributable to carbon oxidation causing a leaching of active iron sites hosted in the carbon matrix.}, language = {en} } @misc{SzakacsLefevreKrammetal., author = {Szakacs, Csaba E. and Lef{\`e}vre, Michel and Kramm, Ulrike Ingrid and Dodelet, Jean-Pol and Vidal, Fran{\c{c}}ois}, title = {A density functional theory study of catalytic sites for oxygen reduction in Fe/N/C catalysts used in H2/O2 fuel cells}, series = {Physical Chemistry Chemical Physics}, volume = {2014}, journal = {Physical Chemistry Chemical Physics}, number = {16}, issn = {1463-9076}, doi = {10.1039/C3CP55331K}, pages = {13654 -- 13661}, abstract = {The oxygen reduction catalytic activity of carbon-supported FeN4 moieties bridging micropores between two graphene sheets was investigated by density functional theory (DFT). Based on the FeN2+2/C structure proposed earlier by our group, two types of FeN2+2/C structures were considered: one mostly planar and one in which the Fe ion is significantly displaced out of the graphitic plane. A structure in which the FeN4 moiety is embedded in an extended graphene sheet (FeNpyri4/C) was also considered. In addition, we have investigated the influence of an axial pyridine group approaching the Fe centre. The formation energy is lowest for the planar FeN2+2/C structure. The overall downhill behaviour of the relative free energy vs. the reaction step suggests that most structures have catalytic activity near zero potential. This conclusion is further supported by calculations of the binding energies of adsorbed O2 and H2O and of the O-O bond lengths of adsorbed O2 and OOH. The side-on interaction of adsorbed O2 is preferred over the end-on interaction for the three basic structures without the axial pyridine. The pyridine coordination produces a stronger binding of O2 for the planar FeN2+2/C and the FeNpyri4/C structures as well as a dominant end-on interaction of O2. The energy levels of the planar FeN2+2/C structure with and without the pyridine ligand are nearly equal for iron spin states S = 1 and S = 2, suggesting that both configurations are formed with similar concentration during the preparation process, as also previously found for two of the iron sites by M{\"o}ssbauer spectroscopy experiments.}, language = {en} } @misc{IndraMenezesSahraieetal., author = {Indra, Arindam and Menezes, Prashanth W. and Sahraie, Nastaran Ranjbar and Bergmann, Arno and Das, Chittaranjan and Tallarida, Massimo and Schmeißer, Dieter and Strasser, Peter and Driess, Matthias}, title = {Unification of Catalytic Water Oxidation and Oxygen Reduction Reactions: Amorphous Beat Crystalline Cobalt Iron Oxides}, series = {Journal of the American Chemical Society}, volume = {2014}, journal = {Journal of the American Chemical Society}, number = {136}, issn = {1520-5126}, doi = {10.1021/ja509348t}, pages = {17530 -- 17536}, abstract = {Catalytic water splitting to hydrogen and oxygen is considered as one of the convenient routes for the sustainable energy conversion. Bifunctional catalysts for the electrocatalytic oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are pivotal for the energy conversion and storage, and alternatively, the photochemical water oxidation in biomimetic fashion is also considered as the most useful way to convert solar energy into chemical energy. Here we present a facile solvothermal route to control the synthesis of amorphous and crystalline cobalt iron oxides by controlling the crystallinity of the materials with changing solvent and reaction time and further utilize these materials as multifunctional catalysts for the unification of photochemical and electrochemical water oxidation as well as for the oxygen reduction reaction. Notably, the amorphous cobalt iron oxide produces superior catalytic activity over the crystalline one under photochemical and electrochemical water oxidation and oxygen reduction conditions.}, language = {en} } @misc{DasHenkelTallaridaetal., author = {Das, Chittaranjan and Henkel, Karsten and Tallarida, Massimo and Schmeißer, Dieter and Gargouri, Hassan and K{\"a}rkk{\"a}nen, Irina and Schneidewind, Jessica and Gruska, Bernd and Arens, Michael}, title = {Thermal and plasma enhanced atomic layer deposition of TiO2: Comparison of spectroscopic and electric properties}, series = {Journal of Vacuum Science and Technology A}, volume = {2015}, journal = {Journal of Vacuum Science and Technology A}, number = {33}, issn = {1520-8559}, doi = {10.1116/1.4903938}, pages = {01A144-1 -- 01A144-8}, abstract = {Titanium oxide (TiO2) deposited by atomic layer deposition (ALD) is used as a protective layer in photocatalytic water splitting system as well as a dielectric in resistive memory switching. The way ALD is performed (thermally or plasma-assisted) may change the growth rate as well as the electronic properties of the deposited films. In the present work, the authors verify the influence of the ALD mode on functional parameters, by comparing the growth rate and electronic properties of TiO2 films deposited by thermal (T-) and plasma-enhanced (PE-) ALD. The authors complete the study with the electrical characterization of selected samples by means of capacitance-voltage and current-voltage measurements. In all samples, the authors found a significant presence of Ti3+ states, with the lowest content in the PE-ALD grown TiO2 films. The observation of Ti3+ states was accompanied by the presence of in-gap states above the valence band maximum. For films thinner than 10 nm, the authors found also a strong leakage current. Also in this case, the PE-ALD films showed the weakest leakage currents, showing a correlation between the presence of Ti3+ states and leakage current density.}, language = {en} } @phdthesis{Staedter, author = {St{\"a}dter, Matthias}, title = {Untersuchungen zu Fanoresonanzen in der resonanten Photoelektronenspektroskopie}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-31860}, pages = {98}, abstract = {Im Mittelpunkt der vorliegenden Arbeit stehen die Untersuchung von Fanointerferenzen innerhalb der wissenschaftlichen Methode der resonanten Photoelektronenspektroskopie. Basis dieser Methode ist die Interpretation aus dem Festk{\"o}rper emittierter Elektronen. Die detektierten Elektronen k{\"o}nnen dabei aus direkten Photoemissionen oder Deaktivierungsprozessen (Spectator-/Participator-Zerf{\"a}lle) nach resonanten Anregungen von Rumpfelektronen stammen. F{\"u}hren beide Prozesse zum selben Systemendzustand, k{\"o}nnen die emittierten Elektronen interferieren, was sich in der Auspr{\"a}gung eines charakteristischen Intensit{\"a}tsprofils, dem Fano-Profil, {\"a}ußert. Die Form des Intensit{\"a}tsprofils kann dabei {\"u}ber den Fanoparameter q beschrieben werden. Im Rahmen dieser Arbeit erfolgte die Diskussion von Fanointerferenzen an organischen (HOPG, Graphenflocken) und oxidischen (CuO, In2O3, SiO2) Materialsystemen. Im HOPG und den untersuchten Graphenflocken konnten mittels der Analyse der Fanoprofile exzitonische Zust{\"a}nde innerhalb der Bandl{\"u}cke nachgewiesen werden. Durch die Untersuchungen am CuO konnte die Variation des Fanoparameters in Abh{\"a}ngigkeit vom Grundzustand des Systems gezeigt werden. Die f{\"u}r die untersuchten In2O3 Einristalle beobachteten Interferenzen beruhen auf der Existenz besetzter Zust{\"a}nde an der Fermienergie. Abschließend konnte eine Korrelation des jeweils auftretenden Fanoparameters mit den beobachteten multi-hole-Auger-Zerf{\"a}llen nachgewiesen werden.}, language = {de} } @misc{GarainSinhaAdhikaryetal., author = {Garain, Samiran and Sinha, Tridib Kumar and Adhikary, Prakriti and Henkel, Karsten and Sen, Shrabanee and Ram, Shanker and Sinha, Chittaranjan and Schmeißer, Dieter and Mandal, Dipankar}, title = {Self-Poled Transparent and Flexible UV Light-Emitting Cerium Complex-PVDF Composite: A High-Performance Nanogenerator}, series = {ACS Applied Materials \& Interfaces}, volume = {2015}, journal = {ACS Applied Materials \& Interfaces}, number = {7}, issn = {1944-8244}, doi = {10.1021/am507522r}, pages = {1298 -- 1307}, abstract = {Cerium(III)-,N-dimethylformamide-bisulfate [Ce(DMF)(HSO4)3] complex is doped into poly(vinylidene fluoride) (PVDF) to induce a higher yield (99\%) of the electroactive phases (β- and γ-phases) of PVDF. A remarkable enhancement of the output voltage (∼32 V) of a nano-generator (NG) based on a nonelectrically poled cerium(III) complex containing PVDF composite film is achieved by simple repeated human finger imparting, whereas neat PVDF does not show this kind of behavior. This high electrical output resembles the generation of self-poled electroactiveβ-phase in PVDF due to the electrostatic interactions between the fluoride of PVDF and the surface-active positive charge cloud of the cerium complex via H-bonding and/or bipolar interaction among the opposite poles of cerium complex and PVDF, respectively. The capacitor charging capability of the flexible NG promises its applicability as piezoelectric-based energy harvester. The cerium(III) complex doped PVDF composite film exhibit an intense photoluminescence in the UV region, which might be due to a participation of electron cloud from negative pole of bipolarized PVDF. This fact may open a new area for prospective development of high-performance energy-saving flexible solid-state UV light emitters.}, language = {en} } @inproceedings{KrenekCimrovaSeifarthetal., author = {Krenek, Radim and Cimrova, Vera and Seifarth, Olaf and Bocharova, Vera and Gorodyska, Ganna and Sidorenko, Alexander and Schmeißer, Dieter and Stamm, Manfred}, title = {Electronic Properties of Metals Embedded into Porous Polymeric Nanotemplates}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 108}, abstract = {We report on electrical measurements (current-voltage characteristics (CVC)) of metals which are templated via porous polymeric nanotemplates. The nanotemplates are based on self-organization of poly(styrene-block 4-vinylpyridine) (PS-PVP). The cylindrical pores of 8 nm in the diameter are ordered in a hexagonal lattice (24 nm in the period). Chromium and gold were embedded in the nanotemplates by magnetron sputtering, nickel was electrodeposited. These thin films were characterized by AFM, ellipsometry, x-ray reflectivity, XAS, XPS and NEXAFS. CVC were acquired by a connection common for light emitting diodes discussing a further use of nanotemplated metals in these devices. To make the connection, the nanotemplate was deposited on glass with ITO electrodes, then metal was embedded into it and finally Al electrodes were evaporated on the device. Behaviour of space charge limited currents (SCLC) was observed. Also, we deal with the electrical mode of AFM as well. Finally electronic behaviour of the metallic nanorods embedded in polymeric nanotemplates is discussed in respective to the structure and chemical composition obtained by AFM and x-ray techniques.}, language = {en} } @inproceedings{TallaridaSohalSchmeisser, author = {Tallarida, Massimo and Sohal, Rakesh and Schmeißer, Dieter}, title = {Electronic properties of the 2x1 3C-SiC surface reconstruction studied with resonant photoemission}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, isbn = {0420-0195}, pages = {S. 239}, abstract = {We have studied the 2x1 reconstructed surface of the 3C-SiC polytype by means of photoemission spectroscopy. The reconstruction was characterized through Si2p and C1s core level and angle-integrated valence band spectroscopy, and confirmed by the observation of a two-domain 2x1 LEED pattern. The electronic properties of this surface were investigated by collecting valence band spectra at photon energies near the Si2p and C1s absorption edges. The results show a strong dependence of the photoemission intensity on the excitation energy with characteristic resonances for certain valence band features. With a detailed study of the resonances we are able to assign the electronic origin of the resonating states and the nature of the electronic transition near the absorption edges.}, language = {en} } @inproceedings{WehnerHofmannSchmeisseretal., author = {Wehner, Stefan and Hofmann, Patrick and Schmeißer, Dieter and Brand, Helmut R. and K{\"u}ppers, J{\"u}rgen}, title = {Pattern formation in the CO + O reaction on Ir(111) surfaces under the influence of noise}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 708}, abstract = {The rate of CO oxidation on Ir(111) surfaces exhibits bistability at T = 500 K in a range of the CO fraction Y in the CO + O reactant gas flux. Quadrupol mass spectrometer measurements of the CO2 rates as a function of the noise strength imposed on Y are well reproduced by parameter-free modeling. We present Photoelectron emission microscopy (PEEM) measurements and 2D calculations of the spatio-temporal patterns of CO and O rich domains. The role of combined multiplicative and additive noise on Y for CO and O domain wall motion and island nucleation-growth-coalescence processes is analysed. For small noise amplitudes few islands nucleate and grow up to some 100 µ m in diameter, before they merge with another island. With increasing noise amplitudes more islands nucleate. With large noise amplitudes bursts to and switching between the branches is observed. The domain wall velocity is found to be independent of the noise strength and island size.}, language = {en} } @inproceedings{WehnerHoffmannSchmeisseretal., author = {Wehner, Stefan and Hoffmann, Patrick and Schmeißer, Dieter and Brand, Helmut R. and K{\"u}ppers, J{\"u}rgen}, title = {CO oxidation on Ir(111) surfaces: consequences of anisotropic diffusion and noise}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 475}, abstract = {The CO oxidation reaction on Iridium(111) surfaces shows bistability in a limited range of the CO fraction of the reactant gas flux Y and a wide range of temperatures T. The two branches are characterized by their reactivity for CO2 formation. The upper rate (high CO2 formation) rate is related to high oxygen coverage on the surface, the lower rate (little CO2 formation) to high CO coverage. Quadrupol mass spectroscopy and PEEM (photoelectron emission microscopy) was employed to study the influence of a noisy reactant gas flux composition on the spatio-temporal pattern development in the CO oxidation reaction on flat Ir(111) and stepped Ir(977) surfaces. PEEM shows nucleation and growth of few oxygen resp. CO islands at small noise amplitudes. Anisotropic diffusion of CO parallel and normal to the steps causes elliptic shapes of large islands. The long axes of the ellipses are aligned along the steps. At increased noise amplitudes the density of islands becomes larger. 2D modeling of the phenomena based on reaction-diffusion differential equations reproduces the experimental findings quite nicely.}, language = {en} } @inproceedings{SeimeHenkelPaloumpaetal., author = {Seime, Bernd and Henkel, Karsten and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Buffer layer investigation of MFIS stacks with an organic ferroelectric layer}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 216}, abstract = {Ferroelectric field effect transistors are considered as future non volatile and non destructive readout memory cells. Conventional Perowskite-type ferroelectric materials are shown to work but they need expensive high temperature and high partial pressure processing steps inducing also unintentional and undefined interfacial layers.A possible low cost solution is the use of poly[vinylidene fluoride trifluoroethylene (P[VDF/TrFE]). This is a ferroelectric polymer which can be spin coated at room temperature onto silicon suited with well defined buffer layers. Using P[VDF/TrFE] we focus on metal ferroelectric insulator semi-conductor (MFIS) structures. In MFIS structure a part of the programming voltage drops over the buffering insulator. We report on attempts to minimize this fraction by optimizing the voltage divider over the buffer and the ferroelectric layers. CV measurements for different thickness of the buffer (10-235nm) and the ferroelectric layer(100nm-1μm) and for different permittivity values of the buffer layer(SiO2, Al2O3, HfO2) will be presented. This work is supported by Deutsche Forschungsgemeinschaft within priority program 1157 (DSCH 745/11-1).}, language = {en} } @inproceedings{MandalMuellerSeifarthetal., author = {Mandal, Dipankar and M{\"u}ller, Klaus and Seifarth, Olaf and Hoffman, Patrick and Henkel, Karsten and Schmeißer, Dieter}, title = {Study of reactions at the interface P(VDF/TrFE)/Al and P(VDF/TrFE)/PEDOT:PSS}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 797}, abstract = {Due to potential use in non volatile memory application, Poly(vinylidene fluoride/trifluoroethylene) (P(VDF-TrFE)) is a great deal of interest, especially to produce organic field effect transistors (OFET). Right now it was found that Aluminum is one of the cost-effective inorganic electrode candidate. On the other hand, poly(3,4 ethylenedioxythiophene):poly(4-styrenesulfonate)(PEDOT:PSS) shows promising behavior for the application as organic electrode. In part of our investigations we have systematically studied surface interactions of organic ferroelectric thin films (P(VDF-TrFE))with inorganic (Al) and organic layers (PEDOT:PSS). By X-ray photoelectron spectroscopy (XPS) is has been found that there is a interfacial reaction with Al and the copolymer. In contrast, for electrodes, made of PEDOT: PSS, we found not such kind of behavior. In this case, we found no evidence for any surface reaction. Furthermore, we present our results concerning the orientation of permanent dipoles in the co-polymer (formed between hydrogen and fluorine atom). Here, we use Near-edge X-ray absorption fine structure (NEXAFS) analysis at the U 49/2 - PGM2 beam line of the BESSY-II Synchrotron. This work is supported by Deutsche Forschungsgemeinschaft (DFG) within priority program 1157 (DSCH 745/11-1).}, language = {en} } @inproceedings{HenkelSohalTorcheetal., author = {Henkel, Karsten and Sohal, Rakesh and Torche, Mohamed and Schwiertz, Carola and Burkov, Yevgen and Schmeißer, Dieter}, title = {PrOx/AlON stacks as a high-k candidate on SiC}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 215}, abstract = {We study the chemical stability and electrical properties of Pr-oxides-SiC MIS stacks. In MISFET devices for high power applications the electric field scaling at the interface between semiconductor and insulator is determined by the ratio of their permittivity values. A high-k material can be used to optimize the performance of such devices. In previous studies we had to understand that the chemical reactivity of the PrOx/SiC interface causes a destructive interaction yielding silicate and graphite formation as well as poor electrical performance after direct deposition of PrOx onto SiC. Therefore we introduced an additional chemically inert layer and in this contribution we focus on PrOx/AlON as a suitable insulator stack. In our spectroscopic investigations we recognized a stable AlON/3C-SiC interface even for annealing steps up to 900∘C. First electrical characterizations are performed on Si substrates and we find a strong improvement in the leakage current by several orders of magnitude down to values of 10-7 A/cm2 at an EOT of 4nm and interface state densities of mean values of 5*1011/eVcm2. We also report on our ongoing electrical characterization of such stacks on SiC substrates. This work is supported by Deutsche Forschungsgemeinschaft within priority program 1157 (DSCH 745/9-2).}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {The initial stages of Chromium growth on Titaniumdioxide-Investigations using synchrotron radiation}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 598}, abstract = {We investigate the interface of Cr-TiO2 during the initial stages of Cr deposition. Experiments are carried out at BESSY II (BL U49/2-PGM2). Using XPS, XAS and ResPES we obtain information about electronic structure at the interface. We confirm the results of growth studies by Christian Winde obtained by TEM-EELS. In addition, we find that Cr deposition induces two gap states which appear about 1 eV and 3 eV below EF. Using ResPES, these states can be identified as being Cr-like and Ti-like respectively. Core-level-XPS and CIS-spectra of the lower gap state indicate the existence of mainly Cr4+ at low coverage (< 1 ML). At higher coverage (≈ 2.5 ML) metallic Cr is observed as well as metallic Ti. Oxidized Cr occurs mainly as Cr3+. CIS-spectra of higher gap state show metallic behavior with both Cr- and Ti-like character. CIS-spectra of lower gap-state confirm the existence of Cr3+. Reference: Christian Winde, Herstellung und Charakterisierung von Cr Schichten auf TiO2 (110)Oberfl{\"a}chen, PhD Thesis, University of Stuttgart, 2002}, language = {en} } @inproceedings{NielsenBauerSennetal., author = {Nielsen, Karl-Wilhelm and Bauer, Sebastian and Senn, Konrad and Goennenwein, Sebastian T. B. and Opel, Matthias and Cezar, Julio C. and Schmeißer, Dieter and Gross, Rudolf}, title = {X-ray magnetic circulardichroism in cobalt-doped ZnO}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 454}, abstract = {Cobalt-doped ZnO is a diluted magnetic semiconductor with a reported Curie-temperature well above 300 K. Nevertheless, the origin of the ferromagnetic exchange still is under debate. To clearify this issue we have investigated cobalt-doped ZnO thin films with x-ray magnetic circular dichroism (XMCD). The (0001)-oriented Zn0.95Co0.05O thin films were grown on (0001) ZnO, (0001) Al2O3, and (0001) ScAlMgO4 substrates by pulsed laser deposition. The magnetic properties were measured by SQUID magnetometry and XMCD. Room temperature magnetization measurements by SQUID magnetometry and XMCD in the fluorescence yield mode reveal ferromagnetic behavior with similar shape of the magnetization curves, however, with different absolute values. XMCD magnetization in total electron yield, which is surface sensitive, show only small magnetic moments, most likely due to a magnetically dead surface layer. This work is supported by the DFG via SPP1157.}, language = {en} } @inproceedings{KachelRichterPhilipetal., author = {Kachel, Krzysztof and Richter, Matthias and Philip, Shine and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Performance of organic solar cells with a ferroelectric component}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 153}, abstract = {Charge dissociation and recombination are important factors for the efficiency of organic solar cells, even in blended systems of different polymers. As a new approach, the influence of additional blended ferroelectric nanoparticles on the solar cell performance is investigated. The ferroelectric dipole of the nanoparticle causes a local field, which could lead to a longer recombination time of the polaron pairs. As solar cell system we use bulk heterojunction cells or bilayer structures based on regioregular poly(3-hexylthiophene) (P3HT) as the donor and phenyl-C61-butyric acid methyl ester (PCBM) as the acceptor molecule. As ferroelectric additive we use the ferroelectric copolymer poly(vinylidene fluoride trifluoroethylene) (P(VDF-TrFE)) or BaTiO3. The copolymer is spincoated as ultrathin film of 20nm, whereas the BaTiO3 is incorporated as nanodispersion into the donor-acceptor blend. We present the solar cell parameters for the different geometries and ferroelectric materials as a function of ferroelectric content and of the alignment of the ferroelectric dipoles after application of an external electric field.}, language = {en} } @inproceedings{KlocekFriedrichZagorodniyetal., author = {Klocek, Jolanta and Friedrich, Daniel and Zagorodniy, Kostyantyn and Schmeißer, Dieter}, title = {Spectroscopic investigations of interaction between C60 fullerene and nitrogen atom from amine group}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 231}, abstract = {We investigated interactions between fullerene molecule and amine group from 3-aminopropyl-trimethoxysilane (3AT). Theoretical calculations show that the material obtained as a result of interactions between 3AT and C60 fullerene may have extremely low dielectric constant around 1.6, so it could be considered as a candidate for ultra low-k (ULK) material applications. We prepared films composed of 3AT and fullerene by using two preparation techniques: spin-coating and evaporation. Interactions between these two components were investigated by using X- ray photoelectron spectroscopy (XPS) and Near Edge X-ray Absorption Fine Structure Spectroscopy (NEXAFS). We found that there are strong chemical reactions between the nucleophilic nitrogen atom from 3AT and electrophilic fullerene molecule. Results of NEXAFS measurements suggest that due to direct interactions between 3AT and C60 the shape of fullerene molecule is changed.}, language = {en} } @inproceedings{KolanekKaravaevTallaridaetal., author = {Kolanek, Krzysztof and Karavaev, Konstantin and Tallarida, Massimo and Schmeißer, Dieter}, title = {Atomic layer deposition of HfO2 onto SiO2 substrates investigated in-situ by non-contact UHV/AFM}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 248}, abstract = {We investigated in-situ the atomic layer deposition (ALD) of HfO2 onto SiO2 substrates with ultra high vacuum (UHV) non-contact atomic force microscope (NC-AFM). The ALD process was started after detailed analysis of the initial Si(001)/SiO2 substrate. The ALD cycles, made by using tetrakis-di-methyl-amido-Hf (TDMAHf) and water as precursors, were performed on the SiO2 substrate maintained at 230 ∘C. We studied the relation between the film growth and the root mean square surface roughness, surface skewness, kurtosis, fractal dimension and correlation length. In the initial stages of the ALD process with our analysis of the surface height histograms we were capable of determination: HfO2 layer thickness, surface coverage and surface roughness of a substrate and deposited material. Observation of the surface height histograms evolution during deposition allowed us to verify conformal and effective ALD growth on SiO2 substrate. With this detailed analysis of the surface topography we confirmed the completion of the first HfO2 layer after four ALD cycles.}, language = {en} } @inproceedings{MichlingTallaridaKolaneketal., author = {Michling, Marcel and Tallarida, Massimo and Kolanek, Krzysztof and Schmeißer, Dieter}, title = {In-situ EELS and UPS measurements on HfO2 ALD layers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {In this contribution we report on our in-situ cycle-by-cycle (up to 10 cycles) investigations of the HfO2 ALD process using the methods of EELS and UPS. We used TDMA-Hf as a precursor and p-type Si wafer with natural oxide as the substrate. The EELS measurements were done with a primary energy of 52,5 eV and the UPS measurements with He I (21,218 eV). The change in the onset of the loss function is readily observed. Already after two cycles the value approach to the bulk value of HfO2. Upon ALD growth there is a remarkable decrease in the intensity of states within the gap. They are rather smooth and saturate after 10 cycles. With UPS we follow the variation of the VB onset and changes in the secondary electron onset. We summarize our data in a band diagram not based on bulk values but on cycle dependent quantities. With these cycle-by-cycle experiments we study the initial growth of HfO2 especially in the very first cycles.}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Synchrotron radiation spectroscopy studies of the initial interaction between cobalt and titanium dioxide}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 652}, abstract = {Small metallic particles deposited on oxide surfaces can serve as heterogeneous catalysts, as for example TiO2 supported cobalt is a known Fischer-Tropsch-Catalyst. The goal of the presented studies is to investigate the interaction between cobalt and TiO2 in the initial step of growth by synchrotron radiation based spectroscopy. PES studies of TiO2 supported cobalt show a reduction of the oxide support, accompanied by an oxidation of the deposited material. The oxidation is not complete, but metallic cobalt is found already in the very first step of growth. Uniform decrease of both substrate PES lines indicate very weak interaction between overlayer and TiO2. An atomic multiplet calculation including charge transfer and crystal field effects is applied to simulate the experimental Co 2p XAS and XPS spectra of the oxidized component. The results allow the identification of the local coordination as well as the identification of the oxidation state of cobalt.}, language = {en} } @inproceedings{PhilipRichterFriedrichetal., author = {Philip, Shine and Richter, Matthias and Friedrich, Daniel and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Spectroscopic investigations of P3HT/PCBM films for organic BHJ solar cells}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 153}, abstract = {Investigations of the electronic structure and composition of regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) based films using Near Edge X-Ray Absorption Fine Structure (NEXAFS) are presented. The measurements were performed at the U49/2-PGM2 beam line of BESSY II, Berlin recording TEY (total electron yield) and TFY (total fluorescence yield) data. Samples prepared by spin coating a mixture of P3HT dissolved in chloroform and PCBM dissolved in chlorobenzene onto ITO (indium tin oxide) coated glass slides were analyzed. Upon measuring the pure P3HT and PCBM, all reported excitations were observed, whereas the blended system is a weighted superposition of the related peaks. Analyzing the data we calculate the composition of the mixture. We also show angular dependent NEXAFS measurements of the P3HT/PCBM blend in order to measure the orientation and distribution of the P3HT polymer. Additionally, we show a new approach for organic solar cell application. BaTiO3 nanoparticles were incorporated as nanodispersion into the donor-acceptor blend or the ferroelectric copolymer poly(vinylidene fluoride trifluoroethylene) (P(VDF-TrFE)) was spincoated as an ultrathin film below the blend.}, language = {en} } @inproceedings{RichterFriedrichPhilipetal., author = {Richter, Matthias and Friedrich, Daniel and Philip, Shine and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Study of P3HT/PCBM based films by NEXAFS}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 194}, abstract = {In this contribution we report on investigations of the electronic structure and composition of regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) based films by using Near Edge X-Ray Absorption Fine Structure (NEXAFS). The measurements were done at the U49/2-PGM2 beam line of BESSY II, Berlin using TEY (total electron yield) and TFY (total fluorescence yield) detection. The samples were produced by spin casting a mixture of P3HT (dissolved in chloroform) and PCBM (dissolved in chlorobenzene) on ITO (indium tin oxide) coated glass slides. Measurements of pure P3HT and PCBM show all typical excitations, whereas the blended system is a weighted superposition of the related peaks. Analyzing these weighted superposition, we observe in the surface sensitive TEY data an accumulation of P3HT, whereas in the bulk sensitive TFY signal an as expected mixture is found. We also show angular dependent NEXAFS measurements of the P3HT/PCBM blend in order to measure the orientation and distribution of the P3HT polymer. Additionally, we will show a new approach for organic solar cell application by introducing ferroelectric nanoparticles into the mixture.}, language = {en} } @inproceedings{SchmidtSchmeisser, author = {Schmidt, Stephan and Schmeißer, Dieter}, title = {Cobalt/nickel mixed oxides - cathode materials for Li-Ion-Batteries}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 596}, abstract = {Replacing Co by large amounts of Ni is considered to reduce costs in Li-Ion-Batteries while maintaining their performance. We are interested in whether this replacement causes changes in the valence band (VB) and conduction band (CB) states or not. Samples were prepared as thin films from nitrate solutions on metal substrates and annealed in air and UHV. The Co to Ni ratio was varied from 50/50 over 40/60 and 30/70 up to 20/80. The results are compared to the pure Co-oxide. Experiments were carried out at the U49/2 beamline at BESSYII, Berlin. XPS of the TM2p states reveals the existence of charge transfer ground states and different oxidation states. NEXAS at the Co2p, Ni2p and O1s edges projects the density of unoccupied states while resonant PES at these edges provides the related partial density of states (pDOS) and thus can be used to distinguish between the different contributions of TM3d and O2p states in the valence band region. We find systematic variation of the VB structure, the valence band maximum and a shift at the O1s absorption edge while the TM2p XPS and absorption spectra do not seem to be affected by the mixing.}, language = {en} } @inproceedings{StarzykTallaridaSchmeisser, author = {Starzyk, Łukasz and Tallarida, Massimo and Schmeißer, Dieter}, title = {Electrically optimized high-κ metal gate MOSFET by specific modification of the band alignment}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 231}, abstract = {The electrical optimization of metal/oxide/semiconductor gate stacks by specific modification of the band alignment for advanced MOS technology incorporating high dielectric constant (κ) materials is explored. Because of requirements concerning continued scaling of MOSFET transistors, gate oxides and cobalt electrode have been grown successively on Si substrate respectively by means of atomic layer deposition (ALD) and evaporation. The thicknesses of high-κ films were around 2 nm. In case of work function engineering, interfaces' chemistry plays a fundamental role. We applied synchrotron radiation based x-ray photoelectron spectroscopy (SR XPS) to characterize our samples, which allows step by step in situ investigations. Co 2p, Al 2p, Hf 4f, Si 2p and O 1s core levels spectra were measured and analyzed. From valence band (VB) spectra we determined Schottky barrier height and electronic bands offsets.}, language = {en} } @inproceedings{WyrodekTallaridaSchmeisseretal., author = {Wyrodek, Jakub and Tallarida, Massimo and Schmeißer, Dieter and Weisheit, Martin}, title = {Determination of interfacial layers in high - k ALD nanolaminate materials by ARXPS and SRXPS measurements}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 232}, abstract = {The interfacial layers of high dielectric constant (high - k) nanolaminate films are here explored. Problems concerning ALD nanolaminate layers deals mainly with lack of accurate methods to determine in depth profile of few nm thick stacks. Modified angle resolved XPS(ARXPS) and synchrotron radiation XPS(SRXPS) are proposed as methods suitable in layer profiling. Studied stacks containing ZrO/HfO or AlO/ZrO, were prepared on Si substrates by atomic layer deposition (ALD). Two sets of experiments were covered. First dealt with initial growth (up to 20 cycles, with thickness d < 2nm) of AlO/ZrO and included layer by layer insitu investigation by SRXPS. Second experiment refer to industrial grown ZrO/HfO films ( d ∼ 3nm ) processed with various parameters resulting in both, layer by layer and homogenous depositions. For those samples exsitu XPS, with angle dependent variation of probing depth, measurements were covered. By comparing obtained intensity ratios for different angles with computational developed stack model it was found that no simple layer by layer but some intermixing growth occurred including interaction with silicon substrate.}, language = {en} } @inproceedings{BergholzSchmeisser, author = {Bergholz, Matthias and Schmeißer, Dieter}, title = {Band gap determination of thin Praseodymiumoxide layers on Aluminiumoxynitride films}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 243}, abstract = {High-k dielectrics are important as never bevore in semiconductor industry. We investigate Pr2O3 as one representative of this group on Silicon and Silicon-Aluminium oxynitride substrates. In earlier work we observed the positive influence of this AlOxNy intermediate layer on the electrical properties of the Pr2O3 layer. Now we present in-situ EELS, XPS and UPS measurements of gradually grown thin Pr2O3 on AlOxNy. From these measurements we determine the band structure and find a very fast change of the band gap for the first few {\AA}ngstr{\"o}m, coupled with n-type behaviour for the Pr2O3 film. These results are compared with RIXS measurements of a 5 nm Pr2O3 on a 1 nm thick AlOxNy layer.}, language = {en} } @inproceedings{BurkovHenkelSchmeisser, author = {Burkov, Yevgen and Henkel, Karsten and Schmeißer, Dieter}, title = {X-ray photoemission spectroscopy of Aluminium Oxynitride on Si(001) and the rise as buffer layers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 243}, abstract = {Praseodymium oxide (PrxOy) is one of the candidate as high-k transistor gate dielectrics, but aluminium oxynitride (AlxONy) as buffer layer is needed to prevent diffusions from the silicon into PrxOy and to hinder charge injection from the semiconductor into the insulator. The thermal stability and thickness dependence of aluminum oxynitride (AlxONy) has been investigated by synchrotron radiation photoemission spectroscopy (SR-PES). AlxONy layers were prepared by low energy ion-beam assisted deposition (LE-IBAD) at room temperature on a silicon substrate cleaned with HF-acid. Aluminium oxynitride is stable till 800∘C. From photoemission spectra we can assess that silicon oxynitride is built as first and then the growth of AlxONy follows. Resonant inelastic X-ray scattering measurements with synchrotron radiation have been performed. The combination of X-ray absorption spectroscopy (XAS) and RIXS make possible to determinate the band gap of AlxONy.}, language = {en} } @inproceedings{HenkelSeimePaloumpaetal., author = {Henkel, Karsten and Seime, Bernd and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {C(V) and C(t) measurements on MFIS structures consisting P[VDF/TrFE] as ferroelectric layer}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 828}, abstract = {Ferroelectric Field Effect Transistors (FeFETs) are considered as a candidate for future non volatile and non destructive readout memory cells. A possible low cost solution is the use of poly[vinylidene fluoride trifluoroethylene (P[VDF/TrFE]). Using P[VDF/TrFE] we focus on metal ferroelectric insulator semiconductor (MFIS) capacitor structures. In this contribution we will summarize our investigations related to capacitance measurements in dependence of applied bias (C(V)) and time (C(t)). The thickness of the ferroelectric layer as well as the thickness and the material of the buffer layer have been investigated for optimization of the write voltage. CV measurements at higher temperatures deliver decreased flatband voltage shifts within one CV loop resulting in lower memory windows. At temperatures around 100∘C the hysteresis totally vanished, pointing out the ferroelectric behavior of the system. C(t) measurements at a constant bias have been performed for retention analysis of the MFIS stack. After applying a writing pulse we could distinguish between a higher and a lower capacitance state for more than 5 days. This work is supported by Deutsche Forschungsgemeinschaft within priority program 1157 (SCHM 745/11-2).}, language = {en} } @inproceedings{KaravaevTallaridaSchmeisseretal., author = {Karavaev, Konstantin and Tallarida, Massimo and Schmeißer, Dieter and Zschech, Ehrenfried}, title = {In-situ ALD growth of Hafnium oxide films}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 244}, abstract = {We report on a novel system for in-situ atomic layer growth (ALD) of high-k dielectric films. First results were obtained for Hf-oxide samples by using Hf-tetrachloride as precursor and water as oxidizer. We compare the photoelectron spectra of Si2p, O1s and Hf4f of our in-situ prepared films with samples (ex-situ) prepared by industrial ALD reactors and discuss similarities and differences observed in the core level spectra of the various samples by considering the different growth conditions.}, language = {en} } @inproceedings{MandalMuellerSchmeisser, author = {Mandal, Dipankar and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Dipole orientation of the P[VDF-TrFE] co-polymer films: A NEXAFS study}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 840}, abstract = {Ferroelectric properties of copolymers of vinylidene fluoride with trifluoroethylene (P[VDF-TrFE]) has become great deal of interest due to potential use in non volatile memory technology. Permanent dipoles (formed between the alternating hydrogen and fluorine atom within the copolymer) ordering of orientation are crucial for device efficiency. Here we focus on thickness dependence dipole orientation in these co-polymer films. In our systematic studies, we found there is prominent dipole re-orientation effect also for the intrinsic films (~10 nm thickness) before applying the electric field. It is observed after the application of the field, the dipoles re-oriented in opposite direction. Therefore, we conclude that the lowest thickness of the film should have well grown crystalline lamellae structure. As a result, c-axis of crystallites acts as well define manner in plane of the surface and for that reason the b-axis is more free. Because the b-axis is parallel to the polarization direction, it is easy to get a preferred orientation of the dipoles. For thicker films (here up to 100 nm), the average orientation effect is hindered, so a very low re-orientation effect has been observed. For this investigation, we used Near Edge X-ray Absorption Spectroscopy, at the U 49/2-PGM beam line of BESSY-II, Berlin. This work is supported by DFG within SPP1157 (SCHM 745/11-2).}, language = {en} } @inproceedings{MuellerMandalHenkeletal., author = {M{\"u}ller, Klaus and Mandal, Dipankar and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Interface reactions of ferroelectric copolymer layers with different electrode materials}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 830}, abstract = {The ferroelectric copolymer poly(vinylidene fluoride trifluoroethylene) (P(VDF-TrFE)) is a possible material for low cost applications as organic nonvolatile memory element. We present an XPS interface investigation of the copolymer/electrode interface. Below 100nm film thickness, interface phenomena becomes important. Possible interface reactions could lead to a reduction of the ferroelectric functionality.We present a comparative study of the two interfaces Al/P(VDF-TrFE) and PEDOT:PSS/P(VDF-TrFE). The result is a clear indication of a surface reaction in between the Aluminum-electrodes. In contrast, for PEDOT:PSS the measurements shows a layer by layer formation of the interface PEDOT:PSS/PVDF without any reaction. Second, we present a study of remanent polarization of ultrathin spincoated films of the copolymer, in a thickness range from 5 to 100mn, with organic electrodes like PEDOT:PSS. The measurements are carried out by using the flatband shift of a capacitance-voltage (CV) characteristic. This shift of flatband voltage is used as value for the electric polarization of the polymer.}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Direct Observation of d2L2 Charge Transfer States in TiO2 thin films by Resonant Photoelectron Spectroscopy}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 592}, abstract = {We investigate the electronic structure of TiO2 thin films by SR-PES, NEXAFS and ResPES. The films are prepared in a combined in-situ/ex-situ process that leads to stoichiometric thin films (≈ 10 nm) in Rutile structure. We focus on ResPES at the Ti 2p edge. When the photon energy is close to the Ti 2p absorption edge we observe additional features about 13 eV below the valence band main features. These features show clear spectator auger decay at the resonance leading to d0 final state. From this, we deduce the existence of the d2L2 initial charge transfer state as this is the only possible channel that enables the corresponding spectator auger decay. These features have the same origin as the satellite structures observed in core level spectra, esp. 2p and 3p.}, language = {en} } @inproceedings{TallaridaKaravaevSchmeisseretal., author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter and Zschech, Ehrenfried}, title = {Photoemission and absorption spectroscopy for in situ investigations of the ALD growth}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 242}, abstract = {We have investigated the growth of Hf-oxide on Si by means of photoemission and X-ray absorption spectroscopy using synchrotron radiation at Bessy, Berlin. The Hf-oxide layers were grown via atomic layer deposition (ALD) using an in-situ ALD reactor attached to the investigation chamber. The XPS and XAS spectra were measured after every deposition cycle by transferring the sample into the investigation chamber without breaking the vacuum. From the experimental data we have obtained information about the early stages of the Hf-oxide growth, concerning in particular the reactivity of the interface with Si. Due to the possibility to study the layers after every cycle and with different oxidation parameters without exposing them to contaminants, the in situ investigation revealed to be a very important method to understand the growth properties of Hf-oxide.}, language = {en} } @inproceedings{OpelNielsenBaueretal., author = {Opel, Matthias and Nielsen, Karl-Wilhelm and Bauer, Sebastian and Goennenwein, Sebastian T. B. and Gross, Rudolf and Cezar, Julio C. and Schmeißer, Dieter and Simon, J{\"u}rgen and Mader, Werner}, title = {Ferromagnetism and magnetic clusters in cobalt-doped ZnO}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 430}, abstract = {Ferromagnetic semiconductors (FMS) - i.e. semiconductors exhibiting long-range magnetic ordering - are intriguing materials. However, in spite of intensive research in the last decade, the existence of homogeneous FMS with a Curie temperature around or above room temperature still is controversial. A particularly tedious issue are local sample inhomogeneities or magnetic clusters, which can yield strong magnetic signals resembling the behaviour expected for a homogeneous FMS. Using pulsed laser deposition, we have grown cobalt-doped ZnO films on single crystalline ZnO substrates. Combining x-ray magnetic circular dichroism, DC magnetometry, and AC susceptibility measurements with a detailed structural analysis by high resolution x-ray diffraction, transmission electron microscopy, and electron-spectroscopic imaging, we can unambigously trace the characteristic, ferromagnetic-like behaviour of our ZnO:Co samples at room-temperature to nanometer-sized superparamagnetic metallic cobalt precipitates.}, language = {en} } @inproceedings{LazarevaKovalMuelleretal., author = {Lazareva, I. and Koval, Yuri and M{\"u}ller, P. and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Field effect transistor of graphitized polyimide with P(VDF-TrFE) as gate insulator}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 195}, abstract = {Surfaces of polyimide films were graphitized by low-energy ion irradiation. The conductivity was between 10-5 to 200 S/cm [1]. We prepared field effect transistors using this material. Ferroelectric P(VDF-TrFE) was used as gate insulator. The thickness of P(VDF-TrFE) varied from 120 nm to 1200 nm. Properties of P(VDF-TrFE) were investigated by current-voltage measurements of metal/ P(VDF-TrFE)/metal capacitors. We have found that at room temperature, the coercive field of P(VDF-TrFE) does not depend on the film thickness. At lower temperatures the coercive field increases proportionally to the reciprocal temperature. Remnant polarization is 9.5 µC/cm2. It slightly rises with decreasing temperature. Our recent results of field effect mobility, carrier concentration and threshold voltage are presented. [1] I. Lazareva, Y. Koval, M. Alam, S. Str{\"o}msd{\"o}rfer, P. M{\"u}ller, Appl. Phys. Lett. 90, 262108 (2007)}, language = {en} } @inproceedings{BergholzSohalSchmeisser, author = {Bergholz, Matthias and Sohal, Rakesh and Schmeißer, Dieter}, title = {ELS to determine the band gap of thin dielectric layers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 156}, abstract = {In ultra thin layers of high-K materials the value of the band gap can be derived not explicitly although it is a key quantity in the electric behavior. We use ELS with a monochromatized (50 meV - 150 meV) electron gun and primary energies between 20 eV and 30 eV. Starting with the native SiO2/Si(001) layers we find that loss function of the substrate dominates for using primary energies beyond 50 eV. In contrast at energies below 50 eV the loss intensity can be used to derived the band gap with an accuracy of ±200 meV. We compare thin (<3 nm) films of HfOx, Pr2O3,Al2O3 and Si-Oxynitrides and discuss the band gap values as well as the scattered intensity observed within the gap.}, language = {en} } @inproceedings{HenkelTorcheSchwiertzetal., author = {Henkel, Karsten and Torche, Mohamed and Schwiertz, Carola and Paloumpa, Ioanna and Sohal, Rakesh and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Inorganic and organic layers for high-k and organic memory applications}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 127}, abstract = {We report about organic and inorganic MIS stacks for new possibilities for high frequency and high power applications as well as for non volatile memory cell. The organic stack contains a ferroelectric polymer as the functional layer. Poly[vinylidene fluoride trifluoroethylene] (P[VDF/TrFE]) is spin coated from a solution onto oxidised silicon substrates. We report on the polarisation induced flatband voltage shifts. For the inorganic stack our attempt is to combine higk-k dielectrics with high band gap semiconductors (SiC). Praseodymium oxide layers are prepared by electron beam evaporation from Pr6O11 powder and in situ controlling of interface and volume composition (XPS). Praseodymium silicate layers were prepared either by metal evaporation onto a thin ox- ide on top of the semiconductor and following annealing steps or by a wet chemical process out of aqueous Pr(NO3)3 solutions. Using spectro-scopic characterisation we investigate the stability of the various inter-faces within the stacks as well as the reactivity of the metal electrodes on thin Pr2O3. We report the results of electrical characterisation consisting of permittivity values, leakage current and density of interface states.}, language = {en} } @inproceedings{MuellerHenkelPaloumpaetal., author = {M{\"u}ller, Klaus and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {P(VDF/TrFE) as ferroelectric insulation layer for organic field effect transistors}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 101}, abstract = {The ferroelectric polymer poly(vinylidene fluoride trifluoroethylene)(P(VDF-TrFE)) is used as insulating material for organic field effect tran-sistors (OFET) and metal-insulator-semiconductor (MIS)-structures. For the MIS-structures, we find the typical hysteresis in the CV charac-teristic upon increasing the voltage scan window. Based on these results, we fabricate OFET with regioregular poly(3-hexlythiophene)(P3HT) as organic semiconductor. The transistors are constructed in bottom gate architecture with thin layers of spincoated P(VDF-TrFE) as gate insulation (100nm). The drain-source current of the OFET is reversible affected by the polarized gate, which gives opportunities for organic nonvolatile memory elements. We present characteristic features like the hysteretic drain current response or the data retention. Furthermore, we present measurements with Kelvin probe force microscopy, a method which gives informations on the lateral distributions of the surface potential.}, language = {en} } @inproceedings{HoffmannSchmeisserHimpseletal., author = {Hoffmann, Patrick and Schmeißer, Dieter and Himpsel, Franz J. and Engelmann, Hans-J{\"u}rgen and Zschech, Ehrenfried and Stegmann, Heiko and Denlinger, Jonathan D.}, title = {Characterization of Chemical Bonding in Low-K Dielectric Materials for Interconnect Isolation: XAS and EELS Study}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 156}, abstract = {The use of low dielectric constant materials in the on-chip interconnect process reduces interconnect delay, power dissipation and crosstalk noise. In CVD deposited organo-silicate glass (OSG) the substitution of oxygen in SiO2 by methyl groups (-CH3) reduces the permittivity significantly (from 4.0 in SiO2 to 2.6-3.3 in the OSG). However, plasma processing removes C and H containing molecular groups. Therefore, compositional analysis and chemical bonding characterization of structured films with nanometer resolution is necessary. OSG thin films as-deposited and after plasma treatment are studied using XAS and EELS. In both techniques, the fine structure near the C1s edge allows to identify C-H, C-C, and C-O bonds. XAS spectra have been recorded for non-patterned films and EELS spectra for patterned structures. The chemical bonding is compared for as-deposited and plasma-treated low-k materials. The flu-orescence and the electron yield recorded while XAS measurement are compared. Examination of the C 1s near-edge structures reveal a mod-ified bonding of the remaining C atoms in the plasma-treated sample regions.}, language = {en} } @inproceedings{MuellerChowdhuryDremovetal., author = {M{\"u}ller, P. and Chowdhury, F. and Dremov, V. and Koval, Yuri and Lichtenberg, F. and M{\"u}ller, S. and Schmeißer, Dieter and Pentcheva, R.}, title = {Resistive memory switching in perovskite-derivative single crystals}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 818}, abstract = {We investigated several layered perovskite derivatives of the family AnBnO3n+2, such as LaTiO3.41, CaNbO3.41 and SrNbO3.41, which can be considered as a stacking of blocks consisting of 5 perovskite layers. Electric transport across these layers takes place via intrinsic tunnelling. Mesa devices with a cross-sectional area of 50 to 200 µm2 and a height between 30 and 500 nm were fabricated by electron-beam lithography and ion-beam etching. Both dc I-V characteristics and pulsed current injection have shown switching between different resistive states in these materials. The resistive states have long-term stability, which makes them interesting for memory applications. The transport experiments suggest that switching and resistive memory are controlled by trapping and release of charge carriers. Furthermore, photoelectron and NEXAFS spectroscopy of cleaved LaTiO3.41 surfaces have been performed. The results are compared to recent correlated band theory (LDA+U) calculations.}, language = {en} } @inproceedings{SeifarthWalczykLupinaetal., author = {Seifarth, Olaf and Walczyk, Christian and Lupina, Grzegorz and Dabrowski, Jaroslaw and Weidner, G{\"u}nter and Zaumseil, Peter and Schmeißer, Dieter and Storck, Peter and M{\"u}ssig, Hans-Joachim and Schroeder, Thomas}, title = {On the electronic and dielectric characterisation of thin cubic PrO2 layers on Silicon}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 196}, abstract = {For the integration of 100 \% Ge onto the Si platform, a buffer oxide approach has been developed recently, using rare earth oxides to tune the lattice constant between the Si and the Ge. Among these buffer oxides, PrO2 is a prospective candidate with high quality crystalline growth on Si, moderated by an interfacial Pr-silicate between. In order to specify electronic properties of thin PrO2 and its interface on Si(111), especially the width of the band gap, we performed synchrotron radiation based XPS, UPS and XAS measurements at the U49/2 PGM 2 beamline at BESSY II and correlate the results with our structural characterisation performed by TEM and XRD. In order to evaluate the dielectric properties of thin PrO2 layers on Si(111), we performed temperature-, time-, voltage-, and layer thickness-dependent leakage current measurements (J-V). Here, we identified relaxation behaviour in the leakage current, successfully addressed to defect like states inside the Pr-silicate interface layer, corroborated by frequency dependent capacitance versus voltage (C-V) measurements.}, language = {en} } @inproceedings{FriedrichMichlingKloceketal., author = {Friedrich, Daniel and Michling, Marcel and Klocek, Jolanta and Schmeißer, Dieter and Avdoshenko, Stas and Chumakov, Dmytro and Zschech, Ehrenfried}, title = {Study of C60 based films formation by NEXAFS}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 145}, abstract = {The C60 fullerenes and some of its -OH, -CF3 and -Cl derivates are candidates for application as ultra-low-k insulators in the semiconductor industry. Future preparation of thin films based on these materials requires the stability of the substituted fullerenes against chemical handling and processing steps. The latter issue was addressed by our NEXAFS studies that were done by synchrotron radiation at the beam line U49/2-PGM2 at BESSY II. Performed were the C K-edge NEXAFS studies in total fluorescence and total electron yield modes. The C60 based films were deposited on silicon by spraying from solutions. The influence of the different substitutional groups with C60 molecules was studied. The data were compared to the reference spectra of a pure C60 film. For C60(OH)24, C60-Cl2 and C60(CF3)12 a variance of the intensity of the π*-resonance as well as shift to higher energies of 0.5 eV (-OH), 0.6 eV (-F), 0.7 eV (-Cl) were observed. The results confirm the necessary stability of the used C60 derivatives and shall be used for optimization of the film deposition chemistry and conditions.}, language = {en} } @inproceedings{KaravaevTallaridaSchmeisser, author = {Karavaev, Konstantin and Tallarida, Massimo and Schmeißer, Dieter}, title = {Evolution of the interfacial layer during the atomic layer deposition of HfO2 on Si/SiO2 substrates}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 160}, abstract = {We studied the formation of the interfacial layer in the Si/SiO2/HfO2 system using the in-situ Atomic Layer Deposition (ALD) reactor developed in our group [1,2]. We measured the X-ray photoelectron and X-ray absorption spectra with synchrotron radiation at the beamline U49-2/PGM2-BESSY II. The ALD growth was obtained using different Hf-precursors (HfCl4,TEMAHf and TDMAHf) on various prepared substrates at different temperatures. The investigation was carried out in-situ giving the possibility to determine the properties of the grown film after every ALD cycle without breaking the vacuum. We observed the evolution of the Si/SiO2/HfO2 system during the formation of first three Hf-oxide layers, detecting the interfacial growth of SiO2 during the initial ALD cycles from the XPS spectra of Si2p. We discuss how the interfacial layer growth depends on the various ALD parameters. [1] M. Tallarida, K. Karavaev, and D. Schmeisser, J. Appl. Phys. 104, 064116 (2008); [2] M. Tallarida, K. Karavaev, and D. Schmeisser, J. Vac. Sci. Technol. B, accepted for publication.}, language = {en} } @inproceedings{KolanekKaravaevTallaridaetal., author = {Kolanek, Krzysztof and Karavaev, Konstantin and Tallarida, Massimo and Schmeißer, Dieter}, title = {In-situ investigations of the atomic layer deposition of HfO2 with UHV/AFM}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 160}, abstract = {We studied in-situ the atomic layer deposition (ALD) of HfO2 with ultra high vacuum (UHV) atomic force microscope (AFM), using the ALD reactor developed by our group [1, 2]. The reactor was attached to the Omicron Large Sample-UHV/AFM system in the AFM-Lab of the Angewandte Physik-Sensorik chair at the BTU-Cottbus. We investigated different Si(001)/SiO2 substrates and surface preparation techniques performed before the ALD process. After each ALD cycle (using TDMAHf and H2O as precursors), we studied the influence of the HfO2 growth on the root mean square (RMS) roughness; the surface fractal dimension and the height histogram: the surface skewness and kurtosis. We focused on the influence of the substrate temperature on the surface topography during the ALD. The in-situ studies of the ALD process with the UHV/AFM system correlated with the experiments performed with photoelectron spectroscopy can be used for understanding the fundamental properties of the ALD of HfO2 on Si(001). [1] M. Tallarida, K. Karavaev, and D. Schmeisser, J. Appl. Phys. 104, 064116 (2008); [2] M. Tallarida, K. Karavaev, and D. Schmeisser, J. Vac. Sci. Technol. B, accepted for publication.}, language = {en} } @inproceedings{KraatzSchmeisserZschechetal., author = {Kraatz, Matthias and Schmeißer, Dieter and Zschech, Ehrenfried and Ho, Paul S.}, title = {Electromigration simulation for on-chip Cu interconnects}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 161}, abstract = {We are investigating the influence of copper microstructure on electromigration degradation effects and interconnect lifetimes using computer simulation. The simulation is carried out in three dimensions. For the copper microstructure, a Monte Carlo technique was used to model the Cu grain growth. Different diffusivities where applied to grain boundaries and top interface of the interconnect model according to the qualitative crystallographic orientation of adjacent grains. The grain boundary network and the top interface form the diffusion paths for the electromigration mass transport. Along the diffusion paths, the fluxes of vacancies where calculated including mechanical stress and electromigration driving forces using a finite difference method. Positive flux divergent sites of the FDM lattice are treated as void nucleation sites after a critical vacancy concentration is reached. The resistance increase due to void growth was calculated using a cellular automaton, masking current free regions as quasi voids and adding the resistance of the slices of the lattice normal to the electron flow direction in series. A parallel computing environment was used to generate large numbers of interconnect models in order to obtain a pool of data for statistical analysis of interconnect lifetimes. The results of this analysis will be shown}, language = {en} } @inproceedings{MichlingFriedrichSchmeisseretal., author = {Michling, Marcel and Friedrich, Daniel and Schmeißer, Dieter and Koval, Yuri and M{\"u}ller, Paul}, title = {Study of polyimide after graphitization with low-energy Ar+ Ion irradiation by NEXAFS}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 147}, abstract = {In this contribution we report on investigations of the electronic structure of Ar+ irradiated polyimide samples by using NEXAFS. The NEXAFS measurements were done at the U49/2-PGM2 beam line of BESSY II, Berlin using TEY and TFY detection. Polyimide samples are prepared using low Ar+ dose while the temperature of the samples is varied between 300K and 700K. In the NEXAFS data at the Carbon K-edge we see substantial changes between different samples. The differences appear in particular in the more surface sensitive TEY-Signal. The NEXFS data are consistent with the graphitization of the surface upon Ar+ bombardment as we identify the characteristic absorption bands of graphitic carbon. Its relative content increases with increasing sample temperature. In contrast, in the more bulk sensitive TFY data, the emission characteristic of polyimide is maintained. The possibility to cover insulating polymers with a conducting layer is a great demand for many applications. Because of the relative low price of the basic materials, the irradiation with low-energy Ions will play an important roll in the microelectronic of the future.}, language = {en} } @inproceedings{MuellerSchmeisser, author = {M{\"u}ller, Sebastian and Schmeißer, Dieter}, title = {Investigation of ultra-thin Chromium layers on Titanium Dioxide by resonant photoemission}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 453}, abstract = {Oxide supported metal films and clusters offer interesting properties with a wide range of possible applications. In this context, Titanium Dioxide is chosen as a model substrate due to its simple electronic structure with a d0 configuration. We study the interaction of ultrathin Chromium films deposited on TiO2 film with focus on the modifications of the valence band and band gap region. Normal photoemission in bulk and surface sensitive modes as well as resonant photoemission at the Cr 2p and Ti 2p edges are used to distinguish the different Cr 3d and Ti 3d contributions to the valence band. In the initial step we find to gap states of distinct character with a sharp resonance of the Cr 3d related state at the Cr 2p edge. With increasing layer thickness we observe that this resonance extends to about 20 eV below the Fermi-Energy. Datasets of valence band spectra measured around the Cr 2p edge show 2 resonant mechanisms in this case i.e. a participator channel for the 3d state accompanied by a spectator channel at fixed kinetic energy.}, language = {en} } @inproceedings{RichterMuellerPhilipetal., author = {Richter, Matthias and M{\"u}ller, Klaus and Philip, Shine and Paloumpa, Ioanna and Henkel, Karsten and Schmeißer, Dieter}, title = {Temperature dependence of organic solar cell parameters}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 671}, abstract = {The influence of an annealing step on the parameters of bulk heterojunction organic solar cells is investigated. In order to fabricate the solar cells we use glass coated with ITO (Indiumtinoxide) as a substrate on which the active layer consisting of P3HT and PCBM is spincoated. Al-electrodes are evaporated on top of the active layer. We use PEDOT:PSS as buffer layer. Each sample is annealed at different temperatures for a short time. Between every temperature step the I-V characteristic of the cell is measured. The following parameters are derived afterwards: FF, Isc (density), Voc. Also the efficiency is estimated. The results show a maximum cell efficiency for drying at 100°C for 20sec. A further important step for preparation is the drying procedure of the PEDOT:PSS layer. Here an improvement of about 50\% in cell efficiency is measured after drying at 50°C for 5 days under inert gas atmosphere.}, language = {en} } @inproceedings{TallaridaKaravaevKolaneketal., author = {Tallarida, Massimo and Karavaev, Konstantin and Kolanek, Krzysztof and Schmeißer, Dieter}, title = {Basics of the atomic layer deposition of HfO2 onto Si/SiO2 substrates: in-situ investigations with XPS, XAS and UHV-AFM}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 159}, abstract = {We developed a reactor for investigating in-situ the atomic layer deposition (ALD) of HfO2. X-ray photoelectron and X-ray absorption spectra were collected after each ALD cycle using synchrotron radiation at the beamline U49-2/PGM2 - BESSY II, Berlin. The morphology of the substrate and thin film surfaces was investigated after each ALD cycle with an UHV-AFM microscopy attached to the ALD reactor. We studied the ALD on differently prepared substrates, at different substrate temperatures, and using different Hf-precursors (HfCl4, TEMAHf, TDMAHf). We observed the evolution of the Si/SiO2/HfO2 system during the formation of the first three Hf-oxide layers [1]; we detected the incorporation of Cl into the Hf-oxide films and proposed a mechanism responsible for the Cl contamination [2]; we found evidence of the interfacial-SiO2 growth during the initial ALD cycles and of dipole formation at the HfO2/SiO2 interface. In this contribution we illustrate the basics of the technique used, and discuss the physical-chemical properties of ALD on the basis of the experimental results. [1] M. Tallarida, K. Karavaev, and D. Schmeisser, J. Appl. Phys. 104, 064116 (2008); [2] M. Tallarida, K. Karavaev, and D. Schmeisser, J. Vac. Sci. Technol. B, accepted for publication.}, language = {en} } @inproceedings{TallaridaKaravaevKolaneketal., author = {Tallarida, Massimo and Karavaev, Konstantin and Kolanek, Krzysztof and Schmeißer, Dieter}, title = {In-situ experimental approach to the study of atomic layer deposition with atomic force microscope, X-ray photoelectron and X-ray absorption spectroscopy}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S.176}, abstract = {We describe our experimental approach to the investigation of atomic layer deposition (ALD). ALD is a powerful deposition technique for growing conformal thin films of composite materials with atomically accurate thickness on large area [1]. Despite the enormous industrial interest growing around ALD, its fundamental properties were not yet properly studied. We developed an ALD reactor for the in-situ investigations using XPS, XAS and AFM as experimental techniques. We studied the chemical-physical properties of the growing thin films after each deposition cycle. Here, we illustrate the recent results concerning the ALD of HfO2 obtained using different Hf-precursors on various substrates [2]. We show how the in-situ investigations could deliver an important insight into the fundamental characteristics of ALD and how these information could be used to modify and optimize the deposition parameters. [1] M. Leskel{\"a}, M. Ritala, Thin Solid Films, 409, 138, 2002; [2] M. Tallarida, K. Karavaev, and D. Schmeisser, J. Appl. Phys. 104, 064116 (2008).}, language = {en} } @inproceedings{SeifarthWalczykLupinaetal., author = {Seifarth, Olaf and Walczyk, Christian and Lupina, Grzegorz and Zaumseil, Peter and Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim and Schroeder, Thomas}, title = {The electronic band diagram of thin PrO2(111) / Pr-silicate buffers on Si(111) and its relevance to dielectric properties}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 136}, abstract = {Thin dielectric buffers of cubic PrO2(111) on Si(111) are ideally suited to integrate Ge onto Si by moderating the lattice mismatch between the materials. The leakage current across this dielectric buffer is strongly influenced by the electronic band diagram and defects inside the band gap. Therefore, we measured the band offsets, band gaps and defect positions by means of synchrotron radiation based photoemission spectroscopy techniques (XPS and XAS) with special emphasis on the Pr-silicate interface. In a next step we compare the spectroscopic data with information from dielectric studies, based on temperature dependent leakage current studies. We observe a close relation between dielectric properties and the electronic structure.}, language = {en} } @inproceedings{FriedrichMichlingSchmeisseretal., author = {Friedrich, Daniel and Michling, Marcel and Schmeißer, Dieter and Koval, Yuri and M{\"u}ller, Paul}, title = {Characterization of ion beam modified polyimide layers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 247}, abstract = {Ion beam modified polyimide show high conductivity. In our investigation we focus on the electronic structure and the element composition, in order to understand the mechanism of conductivity. In our experiments we use the methods NEXAFS and PES. The measurements were done at the U49/2-PGM2 beam line of BESSY II, Berlin. We find an increase of the sp2 hybridized graphite contribution, after low Ar+ ion doses bombardment while the temperature of the samples is varied from 300 K to 650 K. In addition we follow the He+ bombardment induced changes by in-situ monitoring of the O1s, N1s content in the polyimide films.}, language = {en} } @inproceedings{DudekLupinaKozłowskietal., author = {Dudek, Peter and Lupina, Grzegorz and Kozłowski, Grzegorz and Dabrowski, Jarek Marek and Lippert, Gunther and M{\"u}ssig, Hans-Joachim and Schmeißer, Dieter and Schroeder, Thomas}, title = {Band structure and electrical properties of MBE grown HfO2 - based alkaline earth perovskites}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 232}, abstract = {Ultra thin dielectric films (<20 nm) deposited on TiN electrodes are interesting for MIM capacitor application. High capacitance density and dielectric permittivity must be accompanied by extremely low leakage currents (10-8 A/cm2) at bias 0.5 V. To achieve such low leakage currents, high band gap and proper band alignment is required. Occupied electronic states can be probed with standard laboratory photoemission methods. Probing of unoccupied states is more challenging. Synchrotron based PES in combination with XAS forms a powerful method to study the band alignment. ASAM end station located at the U 49/2 PGM 2 beamline of BESSY II (Berlin) offers excellent conditions for performing such measurements. We investigated HfO2 - based alkaline earth perovskite - BaHfO3 with subsequent admixture of TiO2, resulting in formation of BaHf0.5Ti0.5O3 compound. The analysis of data indicates that band gap for HfO2 is similar to BaHfO3 and amounts 5.8 eV; for BaHf0.5Ti0.5O3 it decreases to 3.8 eV. We conclude that the addition of TiO2 to BaHfO3 increases significantly the dielectric permittivity but also impacts the band gap alignment. The conduction band offset shrinks, influencing the leakage current behavior.}, language = {en} } @inproceedings{FriedrichKovalMuelleretal., author = {Friedrich, Daniel and Koval, Yuri and M{\"u}ller, Paul and Schmeißer, Dieter}, title = {Electronic structure of thin spin-coated polyimide layers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 311}, abstract = {The conductivity of polyimide layers can be modified by several orders of magnitude by ion beam radiation. In order to understand the electronic structure of the pure polyimide before ion beam modification we focus in our preliminary experiments on spectroscopic investigations of thin as prepared polyimide films. The films were made by spin coating from a PMDA/ODA solution with subsequent vacuum annealing at 350°C. The layer thickness can be controlled by changing the concentration of PMDA/ODA in the solution realizing a thickness down to 3.5nm. For the characterization of the as prepared thin polyimide films the techniques NEXAFS, ResPES, XPS and CIS were applied at the U49/2-PGM2 beam line of Bessy II, Berlin. Our data including the valence band, core levels and absorption spectrum were compared with theoretical LCAO calculations. Based on these results we are able to attribute all spectral features to the specific atomic bonds in the molecule.}, language = {en} } @inproceedings{HoffmannbeckRichterStaedteretal., author = {Hoffmannbeck, David and Richter, Matthias and St{\"a}dter, Matthias and Paloumpa, Ioanna and Henkel, Karsten and Schmeißer, Dieter}, title = {Spectroscopic and microscopic characterization of potential catalysts for the hydrogenation of CO2}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 483}, abstract = {The reduction of CO2 emissions is a general demand of the society in order to avoid irreversible climate changes. We are investigating potential catalysts for the hydrogenation of CO2 in particular for its application in the so called oxyfuel combustion process. In order to understand the catalytic behavior of the investigated materials we use the techniques X-Ray Photoemission (XPS) and -absorption (XAS) Spectroscopy as well as X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The prospective of our work is to figure out the electronic and structural properties of the material and to optimize proper catalysts or design new ones for best catalytic activity. Beside the spectro-microscopic investigations the catalysts are tested under Sabatier reaction conditions in terms of activity, stability and sensitivity against poisoning. In our preliminary work we constructed a Sabatier reactor system with analytical parts based on infrared absorption and mass spectroscopy modules. First spectroscopic and catalytic results achieved on a commercially available Ru/Al2O3 catalyst will be presented.}, language = {en} } @inproceedings{KraatzZhangSchmeisseretal., author = {Kraatz, Matthias and Zhang, Lijuan and Schmeißer, Dieter and Zschech, Ehrenfried and Ho, Paul S.}, title = {Statistical Analysis of Computer-simulated On-Chip Interconnect Electromigration Lifetimes under the Influence of Microstructure and Strengthened Top Interface}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 292}, abstract = {We are investigating the statistics of computer-simulated interconnect electromigration (EM) lifetimes with regard to the effects of microstructure and a strengthened top interface. The degradation process of EM once threatened the entire existence of integrated circuit industry in the 1960s and has remained a major reliability concern. Ongoing miniaturization and the introduction of new materials further complicate the task of EM-resistant chip manufacturing. We have developed a simple two-dimensional finite difference simulation that models the mass transport by electromigration along the grain boundaries and the top interface of interconnect segments that allows us to do calculations of void nucleation and growth. A parallel computer simulates hundreds of interconnects simultaneously and statistical analysis becomes feasible. A Monte Carlo grain growth algorithm (a modified Potts version) is applied to model the grain structure of the interconnect segments. We will show that the simulation can be used to compare simulation and experiment qualitatively. Four cases have been studied: interconnect segments with small/large grains and weak/strong top interface.}, language = {en} } @inproceedings{MbuaMuellerRichteretal., author = {Mbua, Roy and M{\"u}ller, Klaus and Richter, Matthias and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter and Kramm, Ulricke}, title = {Investigation of new Catalysts for PEM Fuel Cells}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 483}, abstract = {Increasing green house emissions amplify global warming concerns worldwide. Fuel cells, based on polymer electrolyte membranes (PEM) are part of the solution to this issue. We aim at developing and testing new catalysts for fuel cells. Platinum catalysts perform best in PEM fuel cells to date but they are very expensive. For fuel cells to be perfectly applicable and economically affordable, an alternative catalyst with similar or even greater efficiency should be developed. Metal phthalocyanines are known to be good oxygen reduction catalysts and are associated with high electron transfer properties. We investigated Cobalt Phthalocyanine in its pure state mixed with Carbon Black (CoPc:Carbon Black=1:9) untreated and also after a treatment in N2 at several temperatures, up to 1000°C for 30 minutes. Results of XPS and EDX analyses reveal that the treatment at higher temperatures causes a rearrangement in the chemical states of Co, N and C atoms. Furthermore, results of cycling voltammetry (CV) analysis reveal that CoPc treated in N2 at 800°C exhibited a higher current density, in conclusion, a higher catalytic activity than the untreated CoPc.}, language = {en} } @inproceedings{MichlingKolanekSchmeisseretal., author = {Michling, Marcel and Kolanek, Krzysztof and Schmeißer, Dieter and Tallarida, Massimo}, title = {A growth model for the HfO2 ALD process}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 294}, abstract = {In this contribution we report on our in-situ2 cycle-by-cycle (up to the 25 cycles) investigation of the HfO2 atomic layer deposition (ALD) process using the method of x-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS). We used Tetrakis-Dimethyl-Amino-Hafnium (TDMA-Hf) and H2O as precursors and p-type Si wafer with native oxide as a substrate. The XPS measurements were carried out at BESSY II in Berlin with primary energies of 150 eV and 640 eV and the EELS measurements were done with a primary energy of 50 eV. We measured the O1s, Si2p core level and the valence band including the Hf 4f core level. From the Hf4f to Si2p ratios taken at each energy we developed a growth model for the first monolayer and for the following layers too. From our data we conclude, that in the first monolayer up to the fourth ALD cycle an island growth occurs. The height of these islands is about 0,5nm. After the first monolayer is completed, a layer- by-layer growth can be expected. In order to proof this observation we have simulated the Hf/Si ratio for different excitation energies and found a very good agreement with our measurement data. The EELS data especially the evaluation of the loss function onset confirm our growth model.}, language = {en} } @inproceedings{PhilipMartinezMuelleretal., author = {Philip, Shine and Martinez, Elias and M{\"u}ller, Klaus and Kunst, Marinus and Schmeißer, Dieter}, title = {Time resolved microwave conductivity measurements of Bulk Heterojunction solar cells}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 301}, abstract = {The time resolved microwave conductivity (TRMC) method was used in order to study the generation and decay kinetics of charge carriers in the Bulk Heterojunction (BHJ) solar cells. The charge carriers were generated with 532nm laser pulses of 10ns FWHM (Full Width at Half Maximum) induced in the cells. The BHJ solar cells used for the measurements had a photoactive layer consisting of a mixture of Poly (3-Hexylthiophene) P3HT and Phenyl-C61-butyric acid methyl ester (PCBM) which was spin coated onto Indium tin oxide (ITO)/glass substrates. In the field of Organic photovoltaic blends, TRMC method is introduced as a new method of direct investigation of the charge carrier lifetime as well as the charge carrier mobility and we were successful in studying the charge carrier lifetime of the reference BHJ solar cells. We also studied the influence of aligned ferroelectric fields on the charge separation in BHJ solar cells. As ferroelectric material, we used the copolymer Poly (vinylidene fluoride - trifluoroethylene) P(VDF-TrFE).}, language = {en} } @inproceedings{RichterSchmeisser, author = {Richter, Matthias and Schmeißer, Dieter}, title = {Electronic structure and optical properties of P3HT - Evidence of 2D-polarons in P3HT}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 311}, abstract = {In this contribution we report on investigations of the electronic structure and optical characteristics of poly(3-hexylthiophene) (P3HT) based films. Various techniques like NEXAFS, SRXPS, UPS, UV-VIS and FTIR were used. X-Ray based measurements were done at the U49/2-PGM2 beam line at BESSYII. The samples were produced by spin casting P3HT dissolved in chloroform and other suitable solvents on ITO (indium tin oxide) coated glass slides and silicon substrates. Regioregular-P3HT is known to form thin films with nanocrystalline lamellae. This 2D structure give rise to additional electronic excitations in photoinduced absorption measurements, which are attributed to 2D-polarons [1]. In the Total Electron Yield (surface sensitive) and Total Fluorescence Yield (bulk sensitive) NEXAFS spectra of regioregular-P3HT three additional features can be found prior to the first typical π* excitation. The nature of these features was further investigated by means of SRXPS and UPS measurements. Energy differences relative to π*-peak maximum (0.54eV, 0.87eV and 2.24eV) suggest that these features are due to 2D-polarons. This presence of polarons is further confirmed by our FTIR and UV-VIS results. [1] Osterbacka et al., Synth. Met. 116 (2001) 317}, language = {en} } @inproceedings{SchmidtSchmeisser, author = {Schmidt, Stefan and Schmeißer, Dieter}, title = {Localized gap states in cobalt/nickel mixed oxides}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 486}, abstract = {Replacing Co by large amounts of Ni is considered to reduce costs in Li-Ion-Batteries while maintaining their performance. We investigate the electronic structure of Co/Ni compounds because of their direct impact on battery operation. Thin Co/Ni oxide films on metal substrates were prepared by dropping/spin-coating from nitrate solutions followed by subsequent annealing in air and UHV. The following Co to Ni ratios have been investigated: 50/50, 40/60, 30/70, and 20/80. The results are compared with the pure Co-oxide and magnetron sputtered LiCoO2 reference samples. Spectroscopic measurements on these samples were carried out at the U49/2 beamline at BESSYII, Berlin. XPS of the transition metal (TM) 2p states reveals the existence of charge transfer ground states and different oxidation states. NEXAFS at the Co L3, Ni L3 and O K edges reflects the density of unoccupied states while resonant PES at these edges provides the related partial density of states (pDOS). Therefore, these techniques can be used in order to distinguish between the different contributions of TM3d and O2p states in the valence band region. We find sharp localized features at the valence band edge and at the O K and Co L3 absorption edges that are discussed to originate from the strong hybridization between metal and oxygen states in that region.}, language = {en} } @inproceedings{TallaridaDessmannStaedteretal., author = {Tallarida, Massimo and Deßmann, Nils and St{\"a}dter, Matthias and Friedrich, Daniel and Michling, Marcel and Schmeißer, Dieter}, title = {Atomic layer deposition of TiO}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {We present a study of the initial growth of TiO2 on Si(111) by atomic layer deposition (ALD). The Si substrate was etched with NH4F before ALD to remove the native oxide film and to produce a Si-H termination. In-situ experiments by means of photoemission and X-ray absorption spectroscopy were conducted with synchrotron radiation on Ti-oxide films produced using Ti-tetra-iso-propoxide (TTIP) and water as precursors. O1s, Ti2p, C1s, and Si2p core level, and O1s and Ti2p absorption edges show the transition of the Ti-oxide properties during the first layers. The growth starts with a very small growth rate (0.03nm/cycle) due to the growth inhibition of the Si-H termination and proceeds with higher growth rate (0.1nm/cycle) after 1.5nm Ti-oxide has been deposited.}, language = {en} } @inproceedings{DasStaedterTallaridaetal., author = {Das, Chittaranjan and St{\"a}dter, Matthias and Tallarida, Massimo and Schmeißer, Dieter}, title = {Investigation of Linear Dichroism in ALD layers of TiO2}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {Titanium dioxide is on the most studied material due to its wide range of applications in various fields such as self cleaning, photocatalysis, solar cell, water splitting, bio-implants, etc. In order to increase its efficiency in water splitting and solar cell, it is necessary to understand the crystal structure and electronic properties in thin films. In our approach we are investigating the X-ray linear dichroism (XLD) of thin layers of TiO2. XLD studies have been done in multiferroics, antiferromagnetic, and ferromagnetic materials, but a very less amount of work have been done in studying XLD effect of TiO2 thin films. These layers are grown by in-situ atomic layer deposition (ALD) system and are investigated with X-ray absorption spectroscopy (XAS) at BESSY II, Berlin. ALD is a promising technique to grow thin films on different substrates conveniently due to its uniform deposition property. XAS study will also help us to better understand the interfacial electronic properties of thin films of TiO2.}, language = {en} } @inproceedings{MuellerHoffmannbeckKirneretal., author = {M{\"u}ller, Klaus and Hoffmannbeck, David and Kirner, Georg and St{\"a}dter, Matthias and Schmeißer, Dieter}, title = {CO2-Methanation by Catalytic Conversion}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {The utilization of CO2 as raw material is an important component of a program for CO2 reduction. A possibility is the production of methane. At a moderate temperature of around 350°C, hydrogenation of CO2 to methane is possible by the Sabatier reaction CO2 + 4H2 ->CH4 +2H2O. Prerequisite for an efficient kinetics of the Sabatier reaction is the application and optimization of catalysts. In this contribution, we present investigations of Ru and Ni catalysts on different substrates. For Ru/Al2O3 catalysts, we found stable operation without degradation within 500 hours with a conversion rate of 80\% at 350°C. For NiO/SiO2 catalysts, a conversion rate of 90\% was found for temperatures of 350-405°C. We also show the investigation of cross sensitivities against SOx and NOx, which are typical contaminations of CO2, generated by the industrial oxyfuel process. In our work the morphology (REM, AFM, specific surface), chemical composition (FTIR, XPS) and phase composition (XRD) of the catalysts are characterized. In addition, we report on thermodesorption (TDS) measurements at atmospheric pressure to determine the amount of adsorbed CO2 under real conditions. The project is funded by the German Ministry of Research and Education (BMBF-GeoEn).}, language = {en} } @inproceedings{PhilipMuellerRichteretal., author = {Philip, Shine and M{\"u}ller, Klaus and Richter, Matthias and Kunst, Marinus and Schmeißer, Dieter}, title = {Study of excited states and a model for exciton-polaron interaction in P3HT}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {Organic semiconductors efficiently harvest light in the region of the solar spectrum due to a high absorption/extinction coefficient.In our work we study the electronic structure and the charge carrier dynamics of polymeric organic semiconductor regioregular poly(3-hexylthiophen-2,5-diyl) (P3HT), an ideal p-type semiconductor and a widely used conjugated polymer, and blends with the fullerene derivative phenyl-C61-butyric acid methyl ester (PCBM), an electron acceptor material. The study was done with the help of time resolved microwave conductivity (TRMC) for contactless investigation of bulk carrier dynamics, optical spectroscopy, ultraviolet photoelectron spectroscopy(UPS) and high resolution X-ray absorption spectroscopy(XAS) which investigates excited states of rr-P3HT. From the data obtained we could infer the positions of the valence and conduction band, the existence of two excitons as well as the co-existence of one dimensional and two dimensional polarons. Based on our spectroscopic data we propose a model in which the scattering of virtual polarons and excitons are shown to create mobile polaronic charge carriers.}, language = {en} } @inproceedings{RichterFriedrichSchmeisser, author = {Richter, Matthias and Friedrich, Daniel and Schmeißer, Dieter}, title = {3h-Auger decay in the π-band of HOPG}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {In this contribution we report on the electronic structure of highly oriented pyrolitic graphite (HOPG). HOPG is a model system because of the clear separation between π- and σ-bands in the valence band regime. X-ray based measurements were done at the U49/2-PGM2 beam line at BESSYII in Berlin. The resonant photoemission spectra (resPES) at the carbon K-edge give a complete picture of the occupied and unoccupied states in these sp2 hybridized system. Above the K-edge the resPES data are dominated by the Auger process causing a C2p4 final state. The Auger lines appear at constant kinetic energy (spectator, 2h) or constant binding energy (participator, 1h). For the features right at the resonance we observe a different Auger decay mechanism. We attribute it to the decay out of an excitonic intermediate state with a long lifetime. It involves three valence hole states. The original primary core hole is filled by a normal KLL Auger decay. The excited electron rests in the excitonic intermediate state and decays later. We discuss the spectral features of such combined spectator-participator decays in detail which are found only close to resonance and only in the localized valence states of excitonic excitation i.e.C1s - 1π* transitions [1, 2, 3]. [1] Richter et al. (2011) BioNanoScience, submitted. [2] Michling et al. (2011) IOP C Ser Mater Sci Eng, submitted. [3] Schmidt et al. (2011) Solid State Ionics, submitted.}, language = {en} } @inproceedings{StaedterSchmeisser, author = {St{\"a}dter, Matthias and Schmeißer, Dieter}, title = {AP-TDS characterization of CO2 methanation catalysts}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {Development of new catalysts and their characterization by TDS (thermal desorption spectroscopy) is used in a wide field of applications. In our group we focus on catalysts usable to convert CO2 towards methane by the Sabatier reaction (CO2 + 4H2 → CH4 + 2H2O at 375∘C). For measuring large numbers of samples we designed an AP-TDS (ambient pressure TDS) chamber where various desorption experiments can be performed without bringing the catalyst into vacuum. The well-defined reaction chamber, in terms of temperature, pressure and gas composition (Ar atmosphere), is separated by a pin hole (∅ = 6 µ m) from an external UHV chamber. Evolving species and their composition are monitored by a mass spectrometer attached to the UHV chamber. Our first measurement results on commercially available NiO/SiO2 and Ru/Al2O3 based catalysts, with focus on the identification and enumeration of different adsorption sites for CO2, will be presented. CO2 saturated samples were heated from RT to 1100∘C (heating rate β = 0.3 K/s) while measuring the evolution of the CO2 content. Our measurements show large numbers of different adsorption sites for NiO (200-750∘C) whereas Ru shows only few different sites around 440∘C. For both catalysts, most of the formerly adsorbed CO2 remains at the surface (at 375∘C) available for methanation.}, language = {en} } @inproceedings{TallaridaMichlingDasetal., author = {Tallarida, Massimo and Michling, Marcel and Das, Chittaranjan and Friedrich, Daniel and St{\"a}dter, Matthias and Schmeißer, Dieter}, title = {Role of substrate chemistry in ALD revealed by in-situ techniques}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {We show recent results of our in-situ investigations where the role of substrate chemistry in ALD is outlined. While the usual strategy to develop new properties of ALD films is to find new precursors or new procedures, the influence of substrate chemistry on the growth properties of ALD films has been often underestimated. This has principally a technical reason, as the usual characterization methods (QMS, FTIR, ellipsometry) are only weakly sensitive to the substrate, and a characterization of substrates before ALD is often not possible. Thanks to the use of in-situ characterization methods, including photoemission and X-ray absorption spectroscopy with synchrotron radiation, we are able to determine chemical properties of substrates before ALD and after either half or complete ALD cycles. The substrate chemistry influences the standard Al2O3 ALD with TMA and water [1,2], as well as the TiO2 ALD with TTIP and either water, O2 or O2-plasma. [1] M. Tallarida, K. Kukli, M. Michling, M. Ritala, M. Leskel{\"a} and D. Schmeisser, Chem. Mater. 23, 3159 (2011); [2] M. Tallarida, C. Adelmann, A. Delabie, S. van Elshocht, M. Caymax, and D. Schmeisser, Appl. Phys. Lett. 92, 042906 (2011).}, language = {en} } @inproceedings{FischerRohrbeckWehneretal., author = {Fischer, Christian B. and Rohrbeck, Magdalena and Wehner, Stefan and Richter, Matthias and Schmeißer, Dieter}, title = {Diamond-Like Carbon Coatings on Selected Plastic Materials}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {The manufacturing of synthetic materials and their wide range of use for daily life is accompanied by essential requirements. Besides the basic performance of materials such as flexibility, elasticity, fracture strength and chemical resistance, further determinants are long term stability or biocompatibility. To overcome mismatches in surface characteristics of optimal parent material they can be customized for their intended use resulting in suitable coatings for profitable applications. The determining factor for such modifications is the preservation of basic material performance in addition to the benefit of further advantages like changed adhesive, improved repellent or antibacterial behavior. Protective coatings of selected plastic materials have been realized by depositing a few layers of diamond-like carbon (DLC). The assembly of soft plastic material and robust DLC coating is important for the resulting material characteristics. The detailed understanding of materials interphasing between these unequal materials and the conjunction of carbon centers in chemically different neighborhood is part of the presented work. Results will be transferable to other plastic materials with diverse needs, e.g. energy storage devices, water treatments and coatings for everyday commodities or industrial parts.}, language = {en} } @inproceedings{RohrbeckFischerWehneretal., author = {Rohrbeck, Magdalena and Fischer, Christian B. and Wehner, Stefan and Richter, Matthias and Schmeißer, Dieter}, title = {Diamond-Like Carbon Coatings on Industrial Polyethylene Surfaces}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {Synthetic materials are used in a wide variety of fields. Depending on the intended application the plastic material must meet specific requirements. Since the material always interacts with its environment, particular attention is required regarding the surface. Possible damage of the plastic material and further risks could be caused by the adhesion of bacteria, biofilm formation and encrustations. Therefore, bacteria-repellent coatings and surface-modified materials that allow for an effective removal of adhered bacteria are of extremely high interest for many applications. In this study Polyethylene (PE) is chosen as simplest model for relevant plastic materials. Surface modification of PE samples is accomplished by plasma-deposited diamond-like carbon (DLC) coatings to achieve increased abrasion strength and bacterial resistance. Two types of nanometer-scaled DLC films with different layer thicknesses are compared by multiscale microscopic analysis. Further spectroscopic measurements with synchrotron radiation are performed. These results will provide an enhanced understanding of layer formation at the interface between the basic plastic material and the DLC coating and will possibly lead to optimal parameters for the surface coating to achieve improved product characteristics.}, language = {en} } @misc{DasTallaridaSchmeisser, author = {Das, Chittaranjan and Tallarida, Massimo and Schmeißer, Dieter}, title = {Si microstructures laminated with a nanolayer of TiO2 as long-term stable and effective photocathodes in PEC devices}, series = {Nanoscale}, journal = {Nanoscale}, number = {7}, issn = {2040-3364}, doi = {10.1039/C5NR00764J}, pages = {7726 -- 7733}, abstract = {Photoelectrochemical (PEC) water splitting is one of the most emerging fields for green energy generation and storage. Here we show a study of microstructured Si covered by a TiO2 nano-layer. The microstructures are prepared by galvanostatic selective etching of Si. The TiO2 nano-layer was deposited by atomic layer deposition (ALD) to protect the microstructured photocathode against corrosion. The obtained microstructured photocathode showed a shift in the onset potential of 400 mV towards the anodic direction compared to bare Si. The Si microstructures laminated with a nano-layer of TiO2 show stability over 60 hours of measurement.}, language = {en} } @inproceedings{HenkelDasSowinskaetal., author = {Henkel, Karsten and Das, Chittaranjan and Sowinska, Małgorzata and Tallarida, Massimo and Schmeißer, Dieter and Gargouri, Hassan and K{\"a}rkk{\"a}nen, Irina and Schneidewind, Jessica and Gruska, Bernd and Arens, Michael}, title = {Charakterisierung von TiO2-ALD-Schichten und deren Nutzung f{\"u}r die Passivierung von Si-Photokathoden}, series = {Tagungsband Photovoltaik-Meeting: Anwendungen-Qualit{\"a}t-Perspektiven, Senftenberg, 15.04.2015}, booktitle = {Tagungsband Photovoltaik-Meeting: Anwendungen-Qualit{\"a}t-Perspektiven, Senftenberg, 15.04.2015}, editor = {Gl{\"u}ck, B. K. and Schmidt, S. and Stein, E. and Raschke, J{\"o}rg-Uwe and Richter, H.}, publisher = {BTU Cottbus-Senftenberg}, address = {Senftenberg}, pages = {3 -- 8}, abstract = {Wir berichten zun{\"a}chst {\"u}ber den Einfluss der Methode der Atomlagenabscheidung auf die TiO2-Schichteigenschaften. Insbesondere wird der Zusammenhang zwischen Ti3+- sowie Interbandzust{\"a}nden mit elektrischen Kennlinien und deren Einfluss auf funktionale Schichteigenschaften diskutiert. Anschließend werden Mikrostrukturierung, Grenzfl{\"a}chen-Engineering und konforme Abscheidung einer TiO2-ALD-Schutzschicht effektiv zur Performance-Steigerung von p-Si-Photokathoden angewendet.}, language = {de} } @misc{NourbakhshAdelmannSongetal., author = {Nourbakhsh, Amirhasan and Adelmann, Christoph and Song, Yi and Lee, Chang Seung and Asselberghs, Inge and Huyghebaert, Cedric and Brizzi, Simone and Tallarida, Massimo and Schmeißer, Dieter and Elshocht, Sven van and Heyns, Marc and Kong, Jing and Palacios, Tom{\´a}s and De Gendt, Stefan}, title = {Graphene oxide monolayers as atomically thin seeding layers for atomic layer deposition of metal oxides}, series = {Nanoscale}, volume = {2015}, journal = {Nanoscale}, number = {7}, issn = {2040-3364}, doi = {10.1039/C5NR01128K}, pages = {10781 -- 10789}, abstract = {Graphene oxide (GO) was explored as an atomically-thin transferable seed layer for the atomic layer deposition (ALD) of dielectric materials on any substrate of choice. This approach does not require specific chemical groups on the target surface to initiate ALD. This establishes GO as a unique interface which enables the growth of dielectric materials on a wide range of substrate materials and opens up numerous prospects for applications. In this work, a mild oxygen plasma treatment was used to oxidize graphene monolayers with well-controlled and tunable density of epoxide functional groups. This was confirmed by synchrotron-radiation photoelectron spectroscopy. In addition, density functional theory calculations were carried out on representative epoxidized graphene monolayer models to correlate the capacitive properties of GO with its electronic structure. Capacitance-voltage measurements showed that the capacitive behavior of Al2O3/GO depends on the oxidation level of GO. Finally, GO was successfully used as an ALD seed layer for the deposition of Al2O3 on chemically inert single layer graphene, resulting in high performance top-gated field-effect transistors.}, language = {en} } @misc{TamangGhoshGarainetal., author = {Tamang, Abiral and Ghosh, Sujoy Kumar and Garain, Samiran and Alam, Md. Mehebub and Haeberle, J{\"o}rg and Henkel, Karsten and Schmeißer, Dieter and Mandal, Dipankar}, title = {DNA-Assisted β‑phase Nucleation and Alignment of Molecular Dipoles in PVDF Film: A Realization of Self-Poled Bioinspired Flexible Polymer Nanogenerator for Portable Electronic Devices}, series = {ACS Applied Materials \& Interfaces}, journal = {ACS Applied Materials \& Interfaces}, number = {7}, issn = {1944-8244}, doi = {10.1021/acsami.5b04161}, pages = {16143 -- 16147}, abstract = {A flexible nanogenerator (NG) is fabricated with a poly(vinylidene fluoride) (PVDF)film, where deoxyribonu-cleic acid (DNA) is the agent for the electroactive β-phase nucleation. Denatured DNA is co-operating to align the molecular-CH2/-CF2 dipoles of PVDF causing piezo- electricity without electrical poling. The NG is capable of harvesting energy from a variety of easily accessible mechanical stress such as human touch, machine vibration, football juggling, and walking. The NG exhibits high piezoelectric energy conversion efficiency facilitating the instant turn-on of several green or blue light-emitting diodes. The generated energy can be used to charge capacitors providing a wide scope for the design of self-powered portable devices.}, language = {en} } @misc{SchmeisserHaeberleRichteretal., author = {Schmeißer, Dieter and Haeberle, J{\"o}rg and Richter, Matthias and Brazda, Petr}, title = {Spin State and Satellite Structures of ε-Fe₂O₃ as determined by Resonant Photoelectron Spectroscopy}, series = {Nuclear Instruments and Methods in Physics Research B}, volume = {2015}, journal = {Nuclear Instruments and Methods in Physics Research B}, number = {364}, issn = {0168-583X}, doi = {10.1016/j.nimb.2015.08.062}, pages = {127 -- 131}, abstract = {We use resonant photoelectron spectroscopy at the Fe2p and the O1s absorption edges to report on spectroscopic investigation of Fe-oxides nanoparticles. We discuss the spectroscopic details like multiple Auger decays, satellite emission in the X-ray absorption process and the core level data. We explain these data by a novel mechanism in which the resonant excitation between Fe3d and Fe4s states are involved. This mechanism is observed when the photo-excited electron becomes polarized by the electron-hole pairs existing in the conduction and valence bands.}, language = {en} } @misc{AlbertonCorreaBrizziSchmeisser, author = {Alberton Corr{\^e}a, Silma and Brizzi, Simone and Schmeißer, Dieter}, title = {Spectroscopic investigation of the electronic structure of thin atomic layer deposition HfO2 films}, series = {Journal of Vacuum Science \& Technology A}, volume = {34}, journal = {Journal of Vacuum Science \& Technology A}, number = {1}, issn = {0734-2101}, doi = {10.1116/1.4935338}, pages = {01A117-1 -- 01A117-8}, abstract = {The electronic structure of HfO2 thin films is investigated employing resonant photoelectron spectroscopy (resPES). The detailed analysis of the O1s resonance profile enables the determination of the partial density of states for the valence and the conduction bands as well as the electronic band gap to be 6.2 eV. The position of the charge neutrality level is evaluated. Thereby, it is demonstrated that the resPES data are able to combine information both for the valence as well as for the conduction band states. In addition, evidences for intrinsic in-gap states attributed to polaronic and charge transfer states are given. Electronic charges within the atomic layer deposition-HfO2films are identified, pointing out that the amount of charges is essential to determine the accurate position of the surface potentials.}, language = {en} } @misc{SowińskaHenkelSchmeisseretal., author = {Sowińska, Małgorzata and Henkel, Karsten and Schmeißer, Dieter and K{\"a}rkk{\"a}nen, Irina and Schneidewind, Jessica and Naumann, Franziska and Gruska, Bernd and Gargouri, Hassan}, title = {Plasma-enhanced atomic layer deposition of titanium oxynitrides films: A comparative spectroscopic and electrical study}, series = {Journal of Vacuum Science and Technology A}, journal = {Journal of Vacuum Science and Technology A}, number = {34}, issn = {0734-2101}, doi = {10.1116/1.4936227}, pages = {01A127-1 -- 01A127-9}, abstract = {The process parameters' impact of the plasma-enhanced atomic layer deposition (PE-ALD) method on the oxygen to nitrogen (O/N) ratio in titanium oxynitride (TiOxNy) films was studied. Titanium(IV)isopropoxide in combination with NH3 plasma and tetrakis(dimethylamino) titanium by applying N2 plasma processes were investigated. Samples were characterized by the in situ spectroscopic ellipsometry, x-ray photoelectron spectroscopy, and electrical characterization (current-voltage: I-V and capacitance-voltage: C-V) methods. The O/N ratio in the TiOxNy films is found to be very sensitive for their electric properties such as conductivity, dielectric breakdown, and permittivity. Our results indicate that these PE-ALD film properties can be tuned, via the O/N ratio, by the selection of the process parameters and precursor/coreactant combination.}, language = {en} } @misc{PitthandosReisAlbertonCorreaetal., author = {Pitthan, E. and dos Reis, R. and Alberton Corr{\^e}a, Silma and Schmeißer, Dieter and Boudinov, H. I. and Stedile, F. C.}, title = {Influence of CO annealing in metal-oxide-semiconductor capacitors with SiO2 films thermally grown on Si and on SiC}, series = {Journal of Applied Physics}, journal = {Journal of Applied Physics}, number = {119}, issn = {0021-8979}, doi = {10.1063/1.4939836}, pages = {025307-1 -- 025307-6}, abstract = {Understanding the influence of SiC reaction with CO, a by-product of SiC thermal oxidation, is a key point to elucidate the origin of electrical defects in SiC metal-oxide-semiconductor (MOS) devices. In this work, the effects on electrical, structural, and chemical properties of SiO2/Si and SiO2/SiC structures submitted to CO annealing were investigated. It was observed that long annealing times resulted in the incorporation of carbon from CO in the Si substrate, followed by deterioration of the SiO2/Si interface, and its crystallization as SiC. Besides, this incorporated carbon remained in the Si surface (previous SiO2/Si region) after removal of the silicon dioxide film by HF etching. In the SiC case, an even more defective surface region was observed due to the CO interaction. All MOS capacitors formed using both semiconductor materials presented higher leakage current and generation of positive effective charge after CO annealings. Such results suggest that the negative fixed charge, typically observed in SiO2/SiC structures, is not originated from the interaction of the CO by-product, formed during SiC oxidation, with the SiO2/SiC interfacial region.}, language = {en} } @misc{SchmeisserHaeberle, author = {Schmeißer, Dieter and Haeberle, J{\"o}rg}, title = {Intrinsic localized gap states in IGZO and its parent single crystalline TCOs}, series = {Thin Solid Films}, journal = {Thin Solid Films}, number = {603}, issn = {0040-6090}, doi = {10.1016/j.tsf.2016.02.010}, pages = {206 -- 211}, abstract = {We report on the X-ray absorption data for Indium-Gallium-Zink-Oxide thin films, amorphous ZnO films, amorphous SnOx films, and single crystalline In2O3, Ga2O3, ZnO, and SnO2 data. These absorption data probe the empty conduction band states explicitly. Also they allow for an elemental assignment using resonant excitation to derive the contributions of each metal ion. We find that the lowest states appear right at the Fermi energy and result from configuration interaction induced charge transfer states which we consider as intrinsic gap states.}, language = {en} }