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 - 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 - 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 - 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 - 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 - 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 - 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 - Paloumpa, Ioanna A1 - Yfantis, Alexandros D. A1 - Hoffmann, Patrick A1 - Burkov, Yevgen A1 - Yfantis, Alexandros D. A1 - Schmeißer, Dieter T1 - Mechanisms to inhibit corrosion of Al alloys by polymeric conversion coatings N2 - 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. KW - Polypyrrole KW - Fluorozirconates KW - Fluorotitanates KW - Aluminium KW - Corrosion Y1 - 2004 ER - TY - GEN A1 - Yfantis, Alexandros D. A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter ED - Kainer, Karl Ulrich T1 - Corrosion Protection by Conductive Polymers for Magnesium Alloys T2 - Magnesium, proceedings of the 6th International Conference on Magnesium Alloys and their Applications, November 2003 in Wolfsburg N2 - 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. KW - corrosion protection KW - conductive polymers for magnesium alloys KW - polypyrrole Y1 - 2004 SN - 3-527-30975-6 SP - 605 EP - 610 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Goryachko, Andriy A1 - Paloumpa, Ioanna A1 - Beuckert, Guido A1 - Burkov, Yevgen A1 - Schmeißer, Dieter T1 - The Interaction of Pr2O3 with 4H-SiC(0001)surface JF - Physica status solidi / C N2 - 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. Y1 - 2004 SN - 1610-1634 VL - 1 IS - 2 SP - 265 EP - 268 ER - TY - GEN A1 - Müller, Klaus A1 - Paloumpa, Ioanna A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - A polymer high-k dielectric insulator for organic field effect Transistors T2 - Journal of Applied Physics Y1 - 2005 SN - 0021-8979 VL - 98 IS - 5 SP - S. 056104 ER - TY - GEN A1 - Henkel, Karsten A1 - Sohal, Rakesh A1 - Torche, Mohamed A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Hoffmann, Patrick A1 - Schmeißer, Dieter T1 - Grenzflächenoptimierung für funktionale Dünnschichtsysteme: Oxide und Polymere T2 - Forum der Forschung Y1 - 2005 SN - 0947-6989 VL - 9 IS - 18 SP - 49 EP - 56 ER - TY - JOUR A1 - Müller, Klaus A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter A1 - Henkel, Karsten T1 - Organic thin film transistors with polymer high-k dielectric insulator KW - high-k Y1 - 2006 ER - TY - JOUR A1 - Schmeißer, Dieter A1 - Burkov, Yevgen A1 - Paloumpa, Ioanna A1 - Mandal, Dipankar A1 - Henkel, Karsten T1 - Microscopic and Spectroscopic Characterization of Interfaces and Dielectric Layers for OFET Devices Y1 - 2008 ER - TY - GEN A1 - Müller, Klaus A1 - Henkel, Karsten A1 - Mandal, Dipankar A1 - Seime, Bernd A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Spin coated organic ferroelectric films for non volatile memories KW - organic KW - ferroelectric Y1 - 2011 ER - TY - GEN A1 - Henkel, Karsten A1 - Seime, Bernd A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Buffer layer incestigaions on MFIS capacitors consisting of ferroelectric poly[vinylidene fluoride trifluoroethylene] T2 - IOP conference series : Materials Science and Engineering KW - MFIS capacitors KW - ferroelectric Y1 - 2010 SN - 1757-899X VL - 8 IS - 1 SP - 012036 ER - TY - CHAP A1 - Müller, Klaus A1 - Burkov, Yevgen A1 - Mandal, Dipankar A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Goryachko, Andriy A1 - Schmeißer, Dieter ED - Wöll, Christof T1 - Microscopic and spectroscopic characterization of interfaces and dielectric layers for OFET devices T2 - Organic Electronics : structural and Electronic Properties of OFETs KW - microscopic KW - spectrocsopic KW - dielectric Y1 - 2009 SN - 978-3-527-40810-8 SP - 445 EP - 468 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Henkel, Karsten A1 - Lazareva, I. A1 - Mandal, Dipankar A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Koval, Yuri A1 - Müller, P. A1 - Schmeißer, Dieter T1 - Electrical investigations on metal/ferroelectric/insulator/semiconductor structures using Poly[vinylidene fluoride trifluoroethylene] as ferroelectric layer for organic nonvolatile memory applications KW - metal KW - frerroelectric KW - insulator KW - semiconductor Y1 - 2009 ER - TY - JOUR A1 - Müller, Klaus A1 - Mandal, Dipankar A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Ferroelectric properties of spin-coated ultrathin (down to 10nm) copolymer films KW - ferroelectric KW - spin-coated KW - copolymer Y1 - 2008 ER - TY - CHAP A1 - Henkel, Karsten A1 - Mandal, Dipankar A1 - Seime, Bernd A1 - Paloumpa, Ioanna A1 - Lazareva, I. A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Electrical investigations on MFIS structures consisting P[VDF/TrFE] as ferro-electric layer for non-volatile memory applications T2 - Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin) KW - MFIS, P[VDF/TrFE] KW - ferroelectric KW - non-volatile Y1 - 2008 SP - 159 EP - 160 ER - TY - GEN A1 - Henkel, Karsten A1 - Seime, Bernd A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Optimization of MFIS structures containing poly(vinylidene-fluoride trifluoroethylene) for non-volatile memory applications Y1 - 2010 ER - TY - GEN A1 - Henkel, Karsten A1 - Seime, Bernd A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Buffer layer investigations on MFIS capacitors consisting of ferroelectric poly[vinylidene fluoride trifluoroethylene] Y1 - 2010 ER - TY - CHAP A1 - Müller, Klaus A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Carbon-Plot-Micostructuring for All-Polymer-Transistors Y1 - 2001 ER - TY - CHAP A1 - Yfantis, Alexandros D. A1 - Bourdas, N. A1 - Lambrakopoulos, S. A1 - Yfantis, N. A1 - Paloumpa, Ioanna A1 - Yfantis, Alexandros D. T1 - Conductive polymers precoats-application on metallisation of ABS Y1 - 2003 ER - TY - CHAP A1 - Yfantis, Alexandros D. A1 - Bourdas, N. A1 - Lambrakopoulos, S. A1 - Yfantis, N. A1 - Paloumpa, Ioanna A1 - Yfantis, Alexandros D. T1 - Primers of conductive polymers-application in powder coatings technology Y1 - 2003 ER - TY - CHAP A1 - Yfantis, Alexandros D. A1 - Bourdas, N. A1 - Yfantis, N. A1 - Yfantis, Alexandros D. A1 - Lambrakopoulos, S. A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - A study of anticorrosive conversion coatings based on conductive polymers of pyrrole Y1 - 2002 ER - TY - RPRT A1 - Schwiertz, Carola A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter A1 - Kamieth, P. A1 - Schnegber, P. T1 - Aufbau eines Sensorarrays zur Detektion von umwelt- und tierphysiologisch relevanten Komponenten Y1 - 2001 ER - TY - RPRT A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schwiertz, D. A1 - Schmeißer, Dieter A1 - Kamieth, P. A1 - Schengber, P. T1 - Gezielte Entwicklung von Sensormaterialien und Sensoren zur spezifischen Detektion von schwefel- und stickstoffhaltigen Stoffgruppen Y1 - 2001 ER - TY - JOUR A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schwiertz, B. A1 - Elling, B. A1 - Danz, R. A1 - Büchtemann, A. A1 - Straube, Oliver A1 - Schmeißer, Dieter T1 - Kraftsensoren aus Polymerfolien-Piezoelektrische Polymersensoren für Hochdruckanwendungen Y1 - 2001 ER - TY - RPRT A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Oprea, A. A1 - Appel, Günter A1 - Schmeißer, Dieter A1 - Frandsen, W. A1 - Schölzel, Mario T1 - Entwicklung von Sensoren mit Elektroden aus leitfähigen Polymeren Y1 - 2000 N1 - Teilbericht 16SV335/7 im Gemeinsamen Abschlussbericht zum Verbundprojekt "Sensoren mit mikrostrukturierten Elektroden aus leitfähigen Polymeren", März 2000, Kurzfassung ER - TY - JOUR A1 - Appel, Günter A1 - Mikalo, Ricardo Pablo A1 - Henkel, Karsten A1 - Oprea, A. A1 - Yfantis, Alexandros D. A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Polymeric Electrodes Y1 - 2000 ER - TY - GEN A1 - Müller, Klaus A1 - Richter, Matthias A1 - Friedrich, Daniel A1 - Paloumpa, Ioanna A1 - Kramm, Ulrike Ingrid A1 - Schmeißer, Dieter T1 - Spectroscopic characterization of Cobalt–Phthalocyanine electrocatalysts for fuel cell applications T2 - Solid State Ionics N2 - 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. KW - Co-phthalocyanine KW - Catalysis KW - Oxygen reduction reaction (ORR) KW - XPS KW - NEXAFS Y1 - 2012 U6 - https://doi.org/10.1016/j.ssi.2011.12.013 SN - 1872-7689 IS - 216 SP - 78 EP - 82 ER - TY - GEN A1 - Richter, Matthias A1 - Paloumpa, Ioanna A1 - Friedrich, Daniel A1 - Schmeißer, Dieter T1 - Multiple Auger Decay At Resonant Photo-Excitation In Carbon Thin Films T2 - ECS Transactions N2 - 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. KW - resonant photoelectron spectroscopy KW - graphene KW - HOPG KW - X-ray absorption spectroscopy (XAS) KW - X-ray photoelectron spectroscopy (XPS) Y1 - 2013 U6 - https://doi.org/10.1149/05020.0009ecst VL - 50 IS - 20 SP - 9 EP - 21 ER - TY - CHAP A1 - Seime, Bernd A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Buffer layer investigation of MFIS stacks with an organic ferroelectric layer T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42 N2 - 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). Y1 - 2007 UR - http://www.dpg-verhandlungen.de/year/2007/conference/regensburg/part/df/session/11/contribution/1 SN - 0420-0195 SP - S. 216 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Kachel, Krzysztof A1 - Richter, Matthias A1 - Philip, Shine A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Performance of organic solar cells with a ferroelectric component T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45 N2 - 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. Y1 - 2010 UR - http://www.dpg-verhandlungen.de/year/2010/conference/regensburg/part/cpp/session/27/contribution/6 SN - 0420-0195 SP - S. 153 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Philip, Shine A1 - Richter, Matthias A1 - Friedrich, Daniel A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Spectroscopic investigations of P3HT/PCBM films for organic BHJ solar cells T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45 N2 - 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. Y1 - 2010 SN - 0420-0195 SP - S. 153 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Richter, Matthias A1 - Friedrich, Daniel A1 - Philip, Shine A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Study of P3HT/PCBM based films by NEXAFS T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45 N2 - 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. Y1 - 2010 UR - http://www.dpg-verhandlungen.de/year/2010/conference/regensburg/part/df/session/7/contribution/4 SN - 0420-0195 SP - S. 194 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Henkel, Karsten A1 - Seime, Bernd A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - C(V) and C(t) measurements on MFIS structures consisting P[VDF/TrFE] as ferroelectric layer T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43 N2 - 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). Y1 - 2008 UR - http://www.dpg-verhandlungen.de/year/2008/conference/berlin/part/sysa/session/4/contribution/7 SN - 0420-0195 SP - S. 828 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Müller, Klaus A1 - Mandal, Dipankar A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Interface reactions of ferroelectric copolymer layers with different electrode materials T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 43 N2 - 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. Y1 - 2008 UR - http://www.dpg-verhandlungen.de/year/2008/conference/berlin/part/sysa/session/5/contribution/16 SN - 0420-0195 SP - S. 830 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Lazareva, I. A1 - Koval, Yuri A1 - Müller, P. A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Field effect transistor of graphitized polyimide with P(VDF-TrFE) as gate insulator T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43 N2 - 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. Strömsdörfer, P. Müller, Appl. Phys. Lett. 90, 262108 (2007) Y1 - 2008 UR - http://www.dpg-verhandlungen.de/year/2008/conference/berlin/part/df/session/11/contribution/6 SN - 0420-0195 SP - S. 195 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Henkel, Karsten A1 - Torche, Mohamed A1 - Schwiertz, Carola A1 - Paloumpa, Ioanna A1 - Sohal, Rakesh A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Inorganic and organic layers for high-k and organic memory applications T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41 N2 - 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. Y1 - 2006 UR - http://www.dpg-verhandlungen.de/year/2006/conference/dresden/part/df/session/1/contribution/4 SN - 0420-0195 SP - S. 127 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Müller, Klaus A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - P(VDF/TrFE) as ferroelectric insulation layer for organic field effect transistors T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 41 N2 - 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. Y1 - 2006 UR - http://www.dpg-verhandlungen.de/year/2006/conference/dresden/part/cpp/session/23/contribution/28 SN - 0420-0195 SP - S. 101 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Richter, Matthias A1 - Müller, Klaus A1 - Philip, Shine A1 - Paloumpa, Ioanna A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - Temperature dependence of organic solar cell parameters T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 44 N2 - 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. Y1 - 2009 UR - http://www.dpg-verhandlungen.de/year/2009/conference/dresden/part/syop/session/4/contribution/2 SN - 0420-0195 SP - S. 671 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Hoffmannbeck, David A1 - Richter, Matthias A1 - Städter, Matthias A1 - Paloumpa, Ioanna A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - Spectroscopic and microscopic characterization of potential catalysts for the hydrogenation of CO2 T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46 N2 - 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. Y1 - 2011 UR - http://www.dpg-verhandlungen.de/year/2011/conference/dresden/part/o/session/60/contribution/123 SN - 0420-0195 SP - S. 483 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Mbua, Roy A1 - Müller, Klaus A1 - Richter, Matthias A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter A1 - Kramm, Ulricke T1 - Investigation of new Catalysts for PEM Fuel Cells T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46 N2 - 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. Y1 - 2011 UR - http://www.dpg-verhandlungen.de/year/2011/conference/dresden/part/o/session/60/contribution/119 SN - 0420-0195 SP - S. 483 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Richter, Matthias A1 - Städter, Matthias A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Multiple Auger Decay at resonant photo-excitation in carbon thin films T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - 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. Defects (pits, holes, steps and kinks) can act as localized excitonic states. We use those effects to identify the existence and the quantity of such defect states within the pi*-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. The defect-excitonic states can be either localized in the band-gap at the M-point or in case of surface defects like steps, kinks or pits even at the K-point by losing the pure sp2 character of the 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. KW - resonant photoelectron spectroscopy KW - Auger decay KW - multiple decay KW - carbon thin films Y1 - 2013 UR - http://www.dpg-verhandlungen.de/year/2013/conference/regensburg/part/hl/session/52/contribution/6?lang=de PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Goriachko, Andrii A1 - Müller, Klaus A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Scanning Kelvin Probe Microscopy Investigations of Au-P3HT-Au structures for Organic Field Effect Transistors T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - We report on the scanning Kelvin probe microscopy (SKPM) investigation of the source-channel-drain structures of organic field effect transistor (OFET). A poly-3-hexyl-thiophen (P3HT) organic semiconductor film, spin-coated on a glass-substrate and 65 nm thick, is used as a 2 mkm channel between Au source (drain) electrodes. Depending on the preparation conditions, the P3HT film consists of either amorphous nm-seized molecular clsuters or mkm-long chains. The SKPM allows mapping of electric potential along with the surface topography on the DC-biased structures (8V applied between source and drain). It reveals a linear potential fall in the channel region as well as the abscence of potential jumps (contact resistance) in the electrode/channel regions. This is a direct indication of the top-gate OFET type advantage, which the given structure is suited for. Due to the high spatial resolution of the UHV-based SKPM, doping inhomogenities of the p-type P3HT semiconductor as well as the space charge region on the electron injecting electrode are observed. In addition we present SKPM investigations of the structure with source and drain electrodes but without a semiconductor, showing electric field configuration for the given electrodes geometry. KW - scanning Kelvin probe microscopy (SKPM) KW - organic field effect transistor (OFET) Y1 - 2005 UR - http://www.dpg-verhandlungen.de/year/2005/conference/berlin/part/syoo/session/6/contribution/24?lan=en PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Müller, Klaus A1 - Paloumpa, Ioanna A1 - Schwiertz, Carola A1 - Jahnke, Agnes A1 - Schmeißer, Dieter T1 - All Polymer Field-Effect-Transistors based on Low-Cost-Microstructuring T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - Thin film transistors with P3HT as active layer have been prepared by spin coating. The electrodes for source and drain have been prepared by a low cost plotting method with colloidal graphite or carbon black as the conducting material. PEDOT or carbon black was used as gate electrode. The devices, prepared by different methods and materials have been characterized by electrical measurements, for example, their transfer and output characteristics. Furthermore, the influence of different materials on effects like hysteresis or reproducibility will be compared. In addition, we describe a project investigating new types of biosensors with functionalized gate electrodes. Exchanges of dipole moments or charges by immobilisation of biomolecules will change the electrical characteristic of the transistor, which leads to a sensing signal proportional to their amount. KW - organic field effect transistor KW - low cost printing KW - microstructuring Y1 - 2004 UR - http://www.dpg-verhandlungen.de/year/2004/conference/regensburg/part/syoh/session/5/contribution/75?lang=de PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Styervoyedov, Andriy A1 - Paloumpa, Ioanna A1 - Schmeißer, Dieter T1 - Composition and thermal stability of thin functional oxidic (Pr, La, Y) and metallic (Ru, Ti) layers on Si and SiC substrates T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - Thin Pr-, La- and Y- based oxide layers for applications as gate dielectric in metal-oxide-semiconductor (MOS) structures are investigated with x-ray photoelectron spectroscopy. The films with a thickness of around 2nm have been prepared on Si and SiC wafers by various chemical deposition methods based on nitrate solutions. In addition, we report on Ti- and Ru- based metal contacts prepared in the same way. The film composition is analysed and annealing steps in vacuum up to 900∘C have been applied to test their thermal stability. The interface characteristics, surface composition and thermal stability of MOS functional multilayers have been studied and will be presented. KW - Pr-, La- and Y- based oxides KW - MOS transistor KW - high-k KW - X-Ray photoelectron spectroscopy Y1 - 2005 UR - http://www.dpg-verhandlungen.de/year/2005/conference/berlin/part/ds/session/24/contribution/17?lan=en PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Henkel, Karsten A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - P(VDF/TrFE) as a ferroelectric dielectric for Organic Field effect Transistors in MFIS structure T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - MFIS structures consisting of metal, ferroelectric poly[vinylidene fluoride trifluoroethylene](P[VDF/TrFE]), insulator, semiconductor (Si) are fabricated and the influence of the polarization of the P(VDF/TrFE) on the CV characteristics of these structures is investigated. We find a characteristic ferroelectric hysteresis in the CV curves upon increasing the voltage scan window (e.g.-U...U,U=6...30V, |UP(VDF/TrFE)|≤15V, dP(VDF/TrFE)=300 nm). A writing process with adequate electric fields causes large shifts in the flatband voltage ( Δ UFB>4V for the quoted example before) which are stable over days. We report on our investigations which focus on the switching behavior by varying the parameters like polymer thickness, writing field strength and time, long time stability, reversing voltage and insulating material (SiO2, PMMA (Polymethylmetacrylate)). This material combination is favorable for transfer into our full organic concept of field effect transistors for application as a nondestructive readout memory (NDRO) cell. KW - P(VDF/TrFE) KW - Organic ferroelectric field effect transistor KW - capacitance voltage measurements Y1 - 2005 UR - http://www.dpg-verhandlungen.de/year/2005/conference/berlin/part/syoo/session/6/contribution/39?lan=en PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER -