@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} }