TY - THES A1 - Calvet, Wolfram T1 - Präparation und in-situ Charakterisierung MBE-gewachsener Kupferindiumdisulfid-Schichten KW - Halbleitergrenzflächen KW - Photovoltaik KW - Dünne Schichten KW - Chalkopyrite KW - CuInS2 KW - MBE Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-000000242 UR - http://opus4.kobv.de/opus4-btu/frontdoor/index/index/docId/47 ER - TY - JOUR A1 - Hoffmann, Patrick A1 - Mikalo, Ricardo Pablo A1 - Schmeißer, Dieter T1 - Si(001) surface oxidation by N2O N2 - 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. KW - SI(100) KW - dielectric KW - Oxynitride KW - Interface KW - SI KW - NO Y1 - 2002 ER - TY - JOUR A1 - Mikalo, Ricardo Pablo A1 - Schmeißer, Dieter T1 - Electric contacts on conductive polymers: sodium on poly(3-hexylthiophene-2,5-diyl) N2 - 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. Y1 - 2002 ER - TY - JOUR A1 - Yfantis, Alexandros D. A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter A1 - Yfantis, Alexandros D. T1 - Novel corrosion-resistant films for Mg alloys N2 - 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. KW - polypyrrole KW - polyacrylic KW - coating KW - magnesium KW - corrosion inhibition Y1 - 2002 ER - TY - GEN A1 - Aggour, Mohammed A1 - Stoerkel, Ulrich A1 - Murrell, Chris A1 - Campbell, S. A. A1 - Jungblut, H. A1 - Hoffmann, Patrick A1 - Mikalo, Ricardo Pablo A1 - Schmeißer, Dieter A1 - Lewerenz, Hans-Joachim T1 - Electrochemical interface modification of CuInS2 thin films N2 - 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. KW - thin-film solar cells KW - copper indium disulfide KW - atomic force microscopy (AFM) KW - photoelectron spectroscopy KW - synchrotron radiation KW - Solar-Cell Y1 - 2002 ER - TY - JOUR A1 - Hoffmann, Patrick A1 - Mikalo, Ricardo Pablo A1 - Schmeißer, Dieter T1 - PEEM - a spectromicroscopic tool for mc-Si surface evaluation N2 - 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. KW - multicrystalline silicon KW - photoelectron spectroscopy KW - PEEM Y1 - 2002 ER - TY - GEN A1 - Müller, Klaus A1 - Henkel, Karsten A1 - Mikalo, Ricardo Pablo A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Elektronik mit organischen Materialien N2 - Plastikelektronik, flexible Solarzellen, intelligente Kleidung, neuartige und maßgeschneiderte Transducer für die Gas-, Flüssigkeits- und Biosensorik, all dies sind Anwendungen, die ohne halbleitende Polymere nicht denkbar wären und die Bereiche erschließen, in denen zur Zeit eine regelrechte Goldgräberstimmung herrscht. Mit wichtigen Beiträgen im Grundlagen- und Anwendungsbereich nimmt die BTU Cottbus an dieser Entwicklung teil, u. a. auch durch eine Kooperation mit dem Institut für Mikrobiologie des Carl-Thiem-Klinikums Cottbus.In diesem Artikel werden die Voraussetzungen für 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 Gassensitivität von Polypyrrolelektroden auf Quarz-Mikrowaagen und die Mikrorstukturierung organischer Elektroden werden beschrieben. Y1 - 2002 PB - BTU Cottbus, Eigenverlag ER - TY - CHAP A1 - Schwiertz, Carola A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Sensorsystem zur Unterscheidung von Geruchsmustern in Tierställen N2 - Es wurde ein kontinuierlich arbeitendes, preiswertes Schwingquarz-Mess-System zur olfaktometrischen Überwachung von Tierställen aufgebaut, mit dessen Hilfe im Arbeitsbereich von 65%B0C spezifische Gerüche verschiedener Tierarten unterschieden werden können. Zur Geruchsmustererkennung wurde ein einfaches neuronales Netz verwendet. Olfaktometrische Verdünnungen auf 33% sowie Messwertschwankungen von 5-10% wurden simuliert, wobei die richtige Musterzuordnung durch das Netz nicht beeinflusst wurde. Y1 - 2002 ER - TY - CHAP A1 - Henkel, Karsten A1 - Hoffmann, Patrick A1 - Schmeißer, Dieter T1 - Backpropagation-Netzwerke für ein Zweisensorsystem zur Erfassung von Kohlendioxidkonzentrationen und relativer Luftfeuchte T2 - Sensoren im Fokus neuer Anwendungen : Verbraucherschutz und Lebensmittelkontrolle, Biosysteme und Nanobiotechnologie, Umweltmesstechnik, neue Sensormaterialien, Mess- und Eichwesen N2 - 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 Generalisierungsfähigkeit getestet und miteinander verglichen. Für ein einstufiges Netz konnten Ergebnisse mit Fehlern kleiner 12% für die CO2-Konzentration und kleiner 5% für die Luftfeuchte erzielt werden. Ein zweistufiges Netz erkannte Kategorien der Luftfeuchte 100%-ig, für die CO2-Konzentration wurden Fehler kleiner 9% erreicht, wobei eine deutlich bessere Generalisierungsfähigkeit dieses Netzes im Vergleich zum einstufigen Netz zu verzeichnen ist. Y1 - 2002 SN - 3-935712-71-5 SN - 978-3-935712-71-2 SP - 104 EP - 107 PB - w.e.b. Universitätsverlag CY - Dresden ER - TY - CHAP A1 - Müller, Klaus A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Low-cost-Plot-Technologie fur die Mikrostrukturierung von Gassensoren T2 - Sensoren im Fokus neuer Anwendungen, 5. Dresdner Sensor-Symposium, 10. - 12. Dezember 2001, Dresden N2 - Bei der Herstellung von Mikrosensoren ist die Strukturierung von Elektroden oder elektrischen Zu-leitungen mit einem hohen Miniaturisierungsgrad ein entscheidender Punkt. Dazu müs-sen häufig teure Verfahren (Lithographie, Maskentechniken) herangezogen werden.Dieser Beitrag beschreibt eine low-cost-Technologie zur Herstellung organischer Mikrostrukturen für 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 für die Detektion von Luftfeuchte ein-gesetzt. Die prinzipielle Ein-satzmöglichkeit 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 für das Tuschezeichnen, handelsüblichen Folien für wasserlösliche Tinten als Substrat und kolloidalen Graphit als leitendes Material konnten wir Auflösungen, das heißt insbesondere Kanalbreiten bzw. Elektrodenabstände im Bereich von 20+10%B5m (auf 2cm Länge) her-stellen. Y1 - 2002 SN - 3-935712-71-5 SP - 166 EP - 169 PB - w.e.b. Universitätsverlag CY - Dresden ER - TY - JOUR A1 - Müller, Klaus A1 - Hoffmann, Patrick A1 - Milko, S. A1 - Burkov, Yevgen A1 - Schmeißer, Dieter T1 - PEEM and µ-NEXAFS of Cu-In-S-Surfaces N2 - 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. Y1 - 2002 ER - TY - JOUR A1 - Batchelor, David R. A1 - Hoffmann, Patrick A1 - Schmeißer, Dieter T1 - Photoemission study of Aluminium Steel cold welded joints N2 - 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. Y1 - 2002 ER - TY - JOUR A1 - Jäckel, B. A1 - Thißen, A. A1 - Hunger, Ralf A1 - Klein, A. A1 - Jaegermann, Wolfram A1 - Hoffmann, Patrick A1 - Schmeißer, Dieter T1 - Focus IS-PEEM investigations at U49/II: experimental determination of a magnification function, the contrast mechanism and the spectral resolution Y1 - 2002 ER - TY - CHAP A1 - Schmeißer, Dieter A1 - Hoffmann, Patrick A1 - Müssig, Hans-Joachim T1 - The Pr2O3/Si(001) interface: a mixed Si-Proxide T2 - BESSY annual report 2001 Y1 - 2002 SP - 171 EP - 173 PB - Bessy CY - Berlin ER - TY - JOUR A1 - Schmeißer, Dieter A1 - Hoffmann, Patrick T1 - Characterisation of the PrOx/Si(001) Interface by Photoelectron Spectroscopy Y1 - 2002 ER - TY - JOUR A1 - Seyller, Th. A1 - Sieber, N. A1 - Graupner, R. A1 - James, D. A1 - Riley, J. A1 - Leckey, R. A1 - Polcik, M. A1 - Schmeißer, Dieter T1 - High Resolution Photoelectron Spectroscopy on SiC Surfaces Y1 - 2002 ER - TY - JOUR A1 - Pop, D. A1 - Winter, B. A1 - Batchelor, David R. A1 - Freyer, W. A1 - Weber, R. A1 - Bröcker, D. A1 - Hertel, I. V. A1 - Schmeißer, Dieter A1 - Widdra, Wolf T1 - Copper Satellite Structure in Porphyrazine Compounds Y1 - 2002 ER - TY - JOUR A1 - Gracia, F. A1 - Martin-Concepcion, A. I. A1 - Barranco, A. A1 - Holgado, J. P. A1 - Espinos, J. P. A1 - Yubero, F. A1 - Batchelor, David R. A1 - Schmeißer, Dieter A1 - Gonzalez-Elipe, A. R. T1 - XAS investigation of texture in TiO2 thin films prepared by IBICVD Y1 - 2002 ER - TY - GEN A1 - Lopez, Alberto A1 - Heller, Thomas A1 - Bitzer, Thomas A1 - Richardson, Neville V. T1 - A vibrational study of the adsorption of glycine on clean and Na modified Si (100)-2x1 surfaces T2 - Chemical physics N2 - 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. KW - Silicon KW - Glycine KW - Sodium KW - Ab initio KW - HREELS Y1 - 2002 SN - 0301-0104 VL - 277 IS - 1 SP - 1 EP - 8 ER - TY - GEN A1 - Beerbom, Martin A1 - Mayer, Thomas A1 - Jaegermann, Wolfram A1 - Batchelor, David R. A1 - Schmeißer, Dieter T1 - Synchrotron-induced photoemission of GaAs electrodes after electrochemical treatment in aqueous electrolytes N2 - 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. KW - GAAS(110) KW - GaAs KW - Electrochemistry KW - Aqueous electrolytes KW - Surface engineering Y1 - 2002 ER - TY - JOUR A1 - Sieber, N. A1 - Seyller, Th. A1 - Graupner, R. A1 - Ley, L. A1 - Mikalo, Ricardo Pablo A1 - Hoffmann, Patrick A1 - Batchelor, David R. A1 - Schmeißer, Dieter T1 - Wet-chemical preparation of silicate adlayer reconstructed SiC(0001) surfaces as studied by PIES and LEED N2 - 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. KW - Core level KW - Photoelectron spectroscopy KW - Synchrotron radiation KW - Wet-chemical preparation OXIDE Y1 - 2002 ER - TY - GEN A1 - Lewerenz, Hans-Joachim A1 - Aggour, Mohammed A1 - Murrell, Chris A1 - Kanis, M. A1 - Hoffmann, Patrick A1 - Jungblut, H. A1 - Schmeißer, Dieter T1 - Interface engineering of photoelectrochemically prepared Si surfaces N2 - 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. KW - Mean Free Paths KW - Silicon KW - Range Y1 - 2002 ER - TY - THES A1 - Goryachko, Andriy T1 - Investigations of perspective materials for aggressively scaled gate stacks and contact structures of MOS devices KW - silicon KW - praseodymium oxide KW - tungsten nitride KW - tungsten silicide KW - cobalt silicide KW - scanning tunneling microscopy KW - Angerelection spectroscopy Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-000000342 UR - http://opus4.kobv.de/opus4-btu/frontdoor/index/index/docId/59 ER - TY - JOUR A1 - Batchelor, David R. A1 - Follath, Rolf A1 - Schmeißer, Dieter T1 - Commissioning Results of the BTUC-PGM beamline Y1 - 2001 ER - TY - GEN A1 - Böhme, O. A1 - Lloyd Spetz, Anita A1 - Lundström, Ingemar A1 - Schmeißer, Dieter T1 - Nanoparticles as the Active Element of High-Temperature Metal-Insulator-Silicon Carbide Gas Sensors T2 - Advanced Materials Y1 - 2001 SN - 1521-4095 SN - 0935-9648 VL - 13 IS - 8 SP - 597 EP - 601 ER - TY - GEN A1 - Gürek, A. G. A1 - Appel, Günter A1 - Mikalo, Ricardo Pablo A1 - Schmeißer, Dieter T1 - Synthesis of dihydroxy silicon phthalocyanine tetrasulfonic acid and poly-µ-oxo silicon phthalocyanine tetrasulfonic acid T2 - Journal of Porphyrins and Phthalocyanines Y1 - 2001 SN - 1099-1409 SN - 1088-4246 VL - 5 IS - 10 SP - 751 EP - 757 ER - TY - GEN A1 - Henkel, Karsten A1 - Oprea, A. A1 - Paloumpa, Ioanna A1 - Appel, Günter A1 - Schmeißer, Dieter A1 - Kamieth, P. T1 - Selective polypyrrole electrodes for quartz microbalances : NO2 and gas flux sensitivities T2 - Sensors and Actuators : B, Chemical 76(2001)1-3 Y1 - 2001 SN - 0925-4005 VL - 76 IS - 1-3 SP - 124 EP - 129 ER - TY - GEN A1 - Hoffmann, Patrick A1 - Mikalo, Ricardo Pablo A1 - Yfantis, Alexandros D. A1 - Batchelor, David R. A1 - Appel, Günter A1 - Schmeißer, Dieter T1 - A Spectro-Microscopic Approach for Thin Film Analysis Grain Boundaries in mc-Si and Sn/SnO2 Nano Particles T2 - Microchimica Acta Y1 - 2001 SN - 1436-5073 SN - 0026-3672 VL - 136 IS - 3-4 SP - 109 EP - 113 ER - TY - JOUR A1 - Lopez, A. A1 - Bitzer, Thomas A1 - Heller, Thomas A1 - Richardson, Neville V. T1 - Adsorption of water on alkoxy modified Si(1 0 0), Si(1 1 3) and Si(1 1 5) surfaces Y1 - 2001 ER - TY - JOUR A1 - Lopez, A. A1 - Bitzer, Thomas A1 - Heller, Thomas A1 - Richardson, Neville V. T1 - Adsorption of maleic anhydride on Si(1 0 0)-2 x 1 JF - Surface Science Y1 - 2001 SN - 0039-6028 VL - 477 SP - 219 EP - 226 ER - TY - JOUR A1 - Mikalo, Ricardo Pablo A1 - Appel, Günter A1 - Hoffmann, Patrick A1 - Schmeißer, Dieter T1 - Band Bending in Doped Conducting Polypyrrole Interaction with Silver Y1 - 2001 ER - TY - JOUR A1 - Mikalo, Ricardo Pablo A1 - Appel, Günter A1 - Schmeißer, Dieter T1 - Conductivity of Silver exposed Polypyrrole Films Y1 - 2001 ER - TY - JOUR A1 - Mikalo, Ricardo Pablo A1 - Hoffmann, Patrick A1 - Batchelor, David R. A1 - Schmeißer, Dieter A1 - Lloyd Spetz, Anita A1 - Lundström, Ingemar T1 - Comparison of HF and ozone treated SiC surfaces Y1 - 2001 ER - TY - JOUR A1 - Schmeißer, Dieter A1 - Mikalo, Ricardo Pablo A1 - Hoffmann, Patrick A1 - Seyller, Th. A1 - Ley, L. A1 - Lloyd Spetz, Anita T1 - Oxide growth on SiC (0001) surfaces Y1 - 2001 ER - TY - JOUR A1 - Sieber, N. A1 - Mantel, B. F. A1 - Seyller, Th. A1 - Ristein, J. A1 - Ley, L. A1 - Heller, Thomas A1 - Batchelor, David R. A1 - Schmeißer, Dieter T1 - Electronic and chemical passivation of hexagonal 6H-SiC surfaces by hydrogen termination Y1 - 2001 ER - TY - CHAP A1 - Batchelor, David R. A1 - Berg, A. A1 - Simon, Sylvio A1 - Wagner, Lothar A1 - Viehweger, Bernd A1 - Schmeißer, Dieter T1 - Development of Joining Techniques through Pressforming of Steel and Aluminium Y1 - 2001 UR - http://www.materialsweek.org/proceedings/index.htm ER - TY - CHAP A1 - Henkel, Karsten A1 - Elling, B. A1 - Danz, R. A1 - Büchtemann, A. A1 - Straube, Oliver A1 - Paloumpa, Ioanna A1 - Yfantis, Alexandros D. A1 - Schmeißer, Dieter T1 - Piezoelectric polymer sensor for high pressures in forming machines Y1 - 2001 UR - http://www.materialsweek.org/proceedings/index.htm ER - TY - CHAP A1 - Hulea, Iulian A1 - Hoffmann, Patrick A1 - Brinza, Monica A1 - Batchelor, David R. A1 - Schmeißer, Dieter T1 - The interface of friction-welded Al-Fe joints. ATB Metallurgy Y1 - 2001 ER - TY - CHAP A1 - Jaegermann, Wolfram A1 - Schmeißer, Dieter T1 - Elementary Processes at Solid/Electrolyte Interfaces Y1 - 2001 ER - TY - CHAP A1 - Yfantis, Alexandros D. A1 - Tsiniarakis, G. A1 - Labrakopoulos, S. A1 - Yfantis, Alexandros D. A1 - Schmeißer, Dieter T1 - Conductive polymers of pyrrole as pigments in organic anticorrosive coatings-application for aluminium alloys Y1 - 2001 ER - TY - THES A1 - Schweizer, Stefan T1 - Dynamisches Verhalten von Silizium-Elektroden in Fluor-haltigen Elektrolyten KW - Silizium KW - Oxidation KW - Voltammogramme KW - Injektion KW - AFM Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-000000526 UR - http://opus4.kobv.de/opus4-btu/frontdoor/index/index/docId/80 PB - Brandenburgische Techn. Univ. CY - Cottbus ER - TY - GEN A1 - Lewerenz, Hans-Joachim A1 - Aggour, Mohammed A1 - Murrell, Chris A1 - Kanis, M. A1 - Jungblut, H. A1 - Jakubowicz, J. A1 - Cox, P. A. A1 - Campbell, S. A. A1 - Hoffmann, Patrick A1 - Schmeißer, Dieter T1 - Initial stages of structure formation on silicon electrodes investigated by photoelectron spectroscopy using synchrotron radiation and in-situ atomic force microscopy T2 - Journal of the Electrochemical Society N2 - 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. Y1 - 2003 SN - 1945-7111 VL - 150 IS - 3 SP - E185 EP - E189 ER - TY - GEN A1 - Hoffmann, Patrick A1 - Schmeißer, Dieter A1 - Roters, G. A1 - Nenyei, Z. T1 - Non-destructive probing of interfacial oxidation and nitridation states at RTA Si-oxides T2 - Thin Solid Films N2 - 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%. KW - Silicon KW - Oxynitride KW - N20 KW - NH3 KW - Photoelectron spectroscopy KW - Ultrathin oxide Y1 - 2003 SN - 0040-6090 VL - 428 IS - 1-2 SP - 216 EP - 222 ER - TY - JOUR A1 - Schmeißer, Dieter A1 - Paloumpa, Ioanna A1 - Hoffmann, Patrick A1 - Burkov, Yevgen A1 - Yfantis, Alexandros D. A1 - Yfantis, Alexandros D. T1 - Preventing Corrosion of Aluminium Alloys by Polymeric Coatings N2 - 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. Y1 - 2003 ER - TY - JOUR A1 - Müller, Klaus A1 - Milko, S. A1 - Schmeißer, Dieter T1 - Preparation of stoichiometric CuInS2-surfaces - an XPS, UPS-study JF - Thin Solid Films N2 - 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. KW - Stoichiometric CuInS2-films KW - Annealing KW - XPS KW - UPS Y1 - 2003 SN - 0040-6090 VL - 431-432 SP - 312 EP - 316 ER - TY - GEN A1 - Müller, Klaus A1 - Burkov, Yevgen A1 - Schmeißer, Dieter T1 - PEEM and my-NEXAFS of Cu-In-S2-surfaces T2 - Thin Solid Films N2 - 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. KW - CuInS2 films KW - Annealing-process KW - PEEM KW - small mu KW - NEXAFS Y1 - 2003 SN - 0040-6090 VL - 431-432 SP - 307 EP - 311 ER - TY - GEN A1 - Schmeißer, Dieter T1 - Valence states of poly(3-hexyl-thiophene) as probed by photoelectron spectra at resonant excitation T2 - Synthetic Metals N2 - 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. KW - Resonant photoelectron spectroscopy KW - Semi-conducting polymers KW - Organic field effect Y1 - 2003 SN - 0379-6779 VL - 138 IS - 1-2 SP - 135 EP - 140 ER - TY - GEN A1 - Müller, Klaus A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Carbon-plot-microstructuring for all-polymer-transistors T2 - Synthetic Metals N2 - 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. KW - Ten micrometer carbon-plot KW - Organic field-effect-transistors KW - Low-cost-technique Y1 - 2003 SN - 0379-6779 VL - 138 IS - 1-2 SP - 271 EP - 273 ER - TY - JOUR A1 - Bär, Werner T1 - Schnelle Biosensorik für die medizinische Diagnostik N2 - 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, können leichter chemisch durch Funktionalisierung modifiziert werden und können sogar in-vitro eingesetzt werden. Anderseits bietet das Prinzip des Feldeffekttransistors neben einer ca. 1000-fachen Verstärkung der Messsignale die Möglichkeit, simultan verschiedene physikalisch-chemische Wechselwirkungsprozesse des Analytenmit dem Polymer auszuwerten (siehe Forum, Heft 13).Als Modellsystem für die Anwendung in der Biosensorik soll die Einsatzmöglichkeit dieser Sensoren in der Nicht-invasiven Diagnostik der Helicobacter pylori- Infektion überprüft werden. Zum Einen existieren hier andere Nachweisverfahren, die als Validierung dienen können, aber den Nachteil haben, das sie relativ teuer und langwierig sind. Zum anderen hätte die Sensorik mit einem Transistor, dem Grundbaustein mikroelektronischer Schaltungen, den Vorteil, daß die Messung direkt, also online erfolgen könnte. Y1 - 2003 ER - TY - GEN A1 - Riess, W. A1 - Schmeißer, Dieter T1 - Organic Materials for Device Applications - Preface T2 - Synthetic Metals Y1 - 2003 SN - 0379-6779 VL - 138 IS - 1–2 ER - TY - GEN A1 - Schmeißer, Dieter A1 - Pressel, Klaus A1 - Yamamoto, Yuji A1 - Tillack, Bernd A1 - Krüger, D. T1 - Ge instabilities near interfaces in Si-SiGe-Si heterostructures T2 - Materials Science & Engineering B N2 - 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. KW - SiGe KW - Depth profiling KW - Interfaces KW - XPS Y1 - 2003 SN - 0921-5107 SN - 1873-4944 VL - 101 IS - 1-3 SP - 208 EP - 211 ER - TY - GEN A1 - Schmeißer, Dieter A1 - Müssig, Hans-Joachim T1 - The Pr2O3 / Si (001) interface studied by synchrotron radiation photo-electron spectroscopy T2 - Solid State Electronics N2 - 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. KW - High-k dielectric material KW - Pr2O3 KW - Interface KW - Silicate Y1 - 2003 SN - 0038-1101 VL - 47 IS - 10 SP - 1607 EP - 1611 ER -