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 - 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 - Egbers, Christoph T1 - Observation of Nanoparticle Aggregation in a tube flow under microgravity conditions T2 - 34th COSPAR Scientific Assembly, The Second World Space Congress, held 10-19 October, 2002 in Houston, TX, USA., meeting abstract Y1 - 2002 UR - http://adsabs.harvard.edu/abs/2002cosp...34E3464E 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 - 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 - CHAP A1 - Futterer, Birgit T1 - 3D-FG-Widerstandsmodellierung: Analyse von Diskretisierungsfehlern bei gitterunabhängiger Elektrodenpositionierung T2 - 19. Kolloquium Elektromagnetische Tiefenforschung, Burg Ludwigstein, 1.10.-5.10.2001 Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b103-emtf197 SP - 111 EP - 119 PB - Dt. Geophysikalische Ges. CY - Potsdam 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 - 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 - 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 - CHAP A1 - Larcher, Thomas von A1 - Egbers, Christoph T1 - LDA-Messungen zur Untersuchung barokliner Instabilitäten, Lasermethoden in der Strömungsmesstechnik 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 - CHAP A1 - Egbers, Christoph T1 - Simulation of Geophysical Fluid Flows under Microgravity (GeoFlow): Flow diagnostics and experiment concept for Fluid Science experiments T2 - Proceedings of 11th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, 8-11th July 2002 Y1 - 2002 UR - http://in3.dem.ist.utl.pt/lxlaser2002/papers/paper_28_2.pdf ER - TY - CHAP A1 - Futterer, Birgit T1 - Minimierung von Diskretisierungsfehlern bei gitterunabhängiger Elektrodenpositionierung T2 - 62. Jahrestagung der Deutschen Geophysikalischen Gesellschaft im Jahr der Geowissenschaften Y1 - 2002 PB - Deutsche Geophysikalische Gesellschaft CY - Hannover ER - TY - CHAP A1 - Rolland, Wolfgang A1 - Arnold, Ingolf ED - Bayerl, Günter T1 - Anthropogene Veränderungen des Wasserhaushaltes der Spree vom 15. bis 19. Jahrhundert T2 - Die Niederlausitz vom 18. Jahrhundert bis heute: eine gestörte Kulturlandschaft? KW - Spree KW - Wasserhaushalt Y1 - 2002 SN - 3-8309-1197-1 SP - 199 EP - 235 PB - Waxmann CY - Münster [u.a.] ER - TY - JOUR A1 - Richter, Frank A1 - Wichter, Lutz T1 - Zur Bemessung von wasserdurchlässigen Pflaster- und Plattenbelägen Y1 - 2002 ER - TY - CHAP A1 - Wichter, Lutz A1 - Kügler, Marcus T1 - Fehlstellen in Düsenstrahlkörpern durch Inhomogenitäten im Baugrund T2 - Vorträge der Baugrundtagung 2002 in Mainz Y1 - 2002 SN - 3-7739-5968-0 SP - 99 EP - 105 PB - Glückauf-Verlag CY - Essen ER - TY - CHAP A1 - Grünewald, Uwe T1 - "Oderflut 1997" - "Weichselflut 2001" - "Elbeflut 2002" T2 - Die Gefahrentage des DKKV Leipzig 2001/Potsdam 2002 : Dokumentation von Vorträgen KW - Hochwasser KW - Elbe Y1 - 2002 SN - 3-933181-30-5 SP - 62 EP - 67 PB - DKKV CY - Bonn ER - TY - BOOK A1 - Achermann, Jo T1 - "Kunstweg, Alpanstad Alpnach Dorf" N2 - Anlässlich der 300-Jahr-Feier Kapelle St. Josef in Alpnachstad Y1 - 2002 SN - 3-908713-25-0 PB - Wallimann CY - Alpnach ER -