TY - GEN A1 - Müller, K. A1 - Goryachko, Andriy A1 - Burkov, Yevgen A1 - Schwiertz, Carola A1 - Ratzke, Markus A1 - Köble, J. A1 - Reif, Jürgen A1 - Schmeißer, Dieter T1 - Scanning Kelvin probe and photoemission electron microscopy of organic source-drain structures T2 - Synthetic Metals Y1 - 2004 VL - 146 IS - 3 SP - 377 EP - 382 ER - TY - CHAP A1 - Israel, Johannes A1 - Rachow, Fabian A1 - Schwiertz, Carola A1 - Charlafti, Evgenia A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Direct CO2-Methanation of flue gas emitted by conventional power plants T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - The catalytic conversion of CO2 with H2 into CH4 is possible by the Sabatier reaction CO2+4H2→CH4+2H2O. Using excess energy from renewable electricity generation, this approach offers an opportunity for recycling of CO2 as synthetic natural gas. In a new concept, we investigate the performance of the Sabatier reaction as direct methanation of flue gas, emitted by conventional power plants. We investigate the Sabatier process in an upscaled system, with a maximum input flow rate of 45 Nm3/h Gas. The performance is investigated in a simulated composition of flue gas and under real conditions at a lignite power plant in Schwarze Pumpe, Brandenburg, Germany. We can achieve a CO2-conversion of up to 90%, with approx. 100% selectivity towards CH4. Under flue gas conditions and at a certain limit of gas flow the system is operated at an autothermal running modus, a steady state equilibrium of exothermic heat production and thermal flow that needs neither external annealing nor cooling. KW - CO2 KW - methanation KW - Sabatier reaction KW - power plant KW - Schwarze Pumpe KW - autothermal mode Y1 - 2017 UR - http://www.dpg-verhandlungen.de/year/2017/conference/muenster/part/ake/session/8/contribution/5 SP - S. 255 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - GEN A1 - Müller, Klaus A1 - Rachow, Fabian A1 - Israel, Johannes A1 - Charlafti, Evgenia A1 - Schwiertz, Carola A1 - Schmeißer, Dieter T1 - Direct Methanation of Flue Gas at a Lignite Power Plant T2 - International Journal of Environmental Science N2 - The combustion of fossil fuels results in CO2 emission, which is one of the primary causes of global warming. An important approach for solving this problem is the fixation, the chemical utilization and the recycling of CO2. Therefore, we investigate the catalytic conversion of CO2 with H2 into methane (CH4) with an upscaled test station at a brown coal power plant. In a completely new strategy, we realize the direct conversion of the CO2 content of the flue gas, without a cleaning process like amine scrubbing or optimized combustion like oxyfuel. Our experiments are performed in matters of catalytic performance, heat production and stability of the catalytic Sabatier process, as a function of the gas flow rate. The catalytic performance is investigated with a simulated composition of flue gas and under real conditions directly at the power plant. The CH4 production by the Sabatier process is realized with a maximum input flow rate of near 50Nm3/h, with 30Nm3/h flue gas and 20Nm3/h hydrogen. For these values, the necessary power scale for hydrogen generation by electrolysis is around 100kW. With synthetic and real flue gas, a conversion up to 99% (for hydrogen surplus) with 100% selectivity is stabilized. The reaction operates in thermal steady state equilibrium without any external energy supply. In consequence, the process of CO2 recycling could be integrated directly as a post combustion process of conventional power plants, without an expensive capturing step, for example. KW - CO2 recycling KW - Power to Gas (PtG) KW - Synthetic Natural Gas (SNG) KW - Sabatier-Reaction KW - Flue Gas Y1 - 2017 UR - http://www.iaras.org/iaras/home/caijes/direct-methanation-of-flue-gas-at-a-lignite-power-plant SN - 2367-8941 IS - 2 SP - 425 EP - 437 ER - TY - CHAP A1 - Israel, Johannes A1 - Rachow, Fabian A1 - Schwiertz, Carola A1 - Charlafti, Evgenia A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Self restriction oft the Sabatier reaction in large scale T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - A main goal for a sustainable energy supply is a long term energy storage system. One opportunity in this research field is the power to gas concept, where the produced gas can be fed in the existing network of natural gas. Here we show in a technical scale how the direct CO2 conversion to methane according the Sabatier reaction, CO2 + 4 H2 → CH4 + 2H2O , is self organized. At a certain limit of gas flow, a steady state equilibrium of exothermic heat production and thermal flow is reached and the reaction needs no further external annealing. We find for the maximum volume rate at the steady state equilibirum a shift of around 250 ∘C above the optimized temperature of the catalytic supported chemical equilibrium. It is shown that also with this setup the used catalyst works with a stable conversion higher than 80 % under the reached temperature and given pressure conditions. KW - methanation KW - Sabatier reaction Y1 - 2015 UR - http://www.dpg-verhandlungen.de/year/2015/conference/berlin/part/ake/session/9/contribution/4?lang=en PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Rachow, Fabian A1 - Israel, Johannes A1 - Schwiertz, Carola A1 - Charlafti, Evgenia A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - CO2 Methanation with different gas mixtures T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - A key issue in the Energiewende in Germany is the storage of excess energy, as it enables energy management systems to react to fluctuating sources and enhances the flexibility of an energy mix. Power to Gas may be the most reasonable approach to store the energy in the form of hydrogen or synthetic natural gas. We study the direct conversion of CO2 by the Sabatier reaction to gain a methane based mixture which can replace natural gas in CHP plants and gas motors and can help to partially reduce the CO2 emission. In laboratory scale we investigated the performance (with IR and QMS) of Ni-based catalyst for different sources of CO2 like clean CO2, CO2 emitted as flue gas from an Oxyfuel power plant or a synthetic mixture with O2, N2 and SO2 in concentration typical for conventional power plants. Measurements from an up-scaled system are also presented, showing data important for a technical application. Here, we are able to convert more than 200kg CO2/day with conversion rates up to 90%. KW - methanation KW - Sabatier reaction KW - contamination KW - catalyst Y1 - 2015 SN - 0420-0195 SP - S. 539 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - GEN A1 - Henkel, Karsten A1 - Torche, Mohamed A1 - Sohal, Rakesh A1 - Karavaev, Konstantin A1 - Burkov, Yevgen A1 - Schwiertz, Carola A1 - Schmeißer, Dieter T1 - Pr-O-Al-N dielectrics for metal insulator semiconductor stacks KW - semiconductor KW - dielectric Y1 - 2011 ER - TY - CHAP A1 - Schwiertz, Carola A1 - Henkel, Karsten A1 - Blei, S. A1 - Heidenreich, R. A1 - Schmeißer, Dieter T1 - Nachweis von Aerosolen (<1µm) mit Schwingquarzimpedanzspektroskopie KW - Schwingquarzimpedanzspektroskopie Y1 - 2009 ER - TY - GEN A1 - Henkel, Karsten A1 - Burkov, Yevgen A1 - Karavaev, Konstantin A1 - Torche, Mohamed A1 - Schwiertz, Carola A1 - Schmeißer, Dieter T1 - Optimization of the AION buffer layer for PrxOy/Si stacks KW - AION buffer Y1 - 2009 ER - TY - JOUR A1 - Henkel, Karsten A1 - Karavaev, Konstantin A1 - Torche, Mohamed A1 - Schwiertz, Carola A1 - Burkov, Yevgen A1 - Schmeißer, Dieter T1 - Al-Oxyxynitride interfacial layer investigations for PrXOY on SiC and Si Y1 - 2008 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 - JOUR A1 - Henkel, Karsten A1 - Sohal, Rakesh A1 - Schmeißer, Dieter A1 - Schwiertz, Carola A1 - Burkov, Yevgen A1 - Torche, Mohamed T1 - Al-oxynitride buffer layer facilities for PrOx/SiC interfaces Y1 - 2007 ER - TY - CHAP A1 - Henkel, Karsten A1 - Sohal, Rakesh A1 - Torche, Mohamed A1 - Schwiertz, Carola A1 - Burkov, Yevgen A1 - Schmeißer, Dieter T1 - PrOx/AlON stacks as a high-k candidate on SiC T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42 N2 - We study the chemical stability and electrical properties of Pr-oxides-SiC MIS stacks. In MISFET devices for high power applications the electric field scaling at the interface between semiconductor and insulator is determined by the ratio of their permittivity values. A high-k material can be used to optimize the performance of such devices. In previous studies we had to understand that the chemical reactivity of the PrOx/SiC interface causes a destructive interaction yielding silicate and graphite formation as well as poor electrical performance after direct deposition of PrOx onto SiC. Therefore we introduced an additional chemically inert layer and in this contribution we focus on PrOx/AlON as a suitable insulator stack. In our spectroscopic investigations we recognized a stable AlON/3C-SiC interface even for annealing steps up to 900∘C. First electrical characterizations are performed on Si substrates and we find a strong improvement in the leakage current by several orders of magnitude down to values of 10−7 A/cm2 at an EOT of 4nm and interface state densities of mean values of 5*1011/eVcm2. We also report on our ongoing electrical characterization of such stacks on SiC substrates. This work is supported by Deutsche Forschungsgemeinschaft within priority program 1157 (DSCH 745/9-2). Y1 - 2007 UR - http://www.dpg-verhandlungen.de/year/2007/conference/regensburg/part/df/session/10/contribution/8 SN - 0420-0195 SP - S. 215 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Henkel, Karsten A1 - Torche, Mohamed A1 - Sohal, Rakesh A1 - Schwiertz, Carola A1 - Hoffmann, Patrick A1 - Schmeißer, Dieter ED - Dudley, Michael T1 - Pr-O-N Dielectrics for MIS Stacks on Silicon and Silicon Carbide Surfaces T2 - Silicon carbide 2006 - materials, processing and devices, symposium held April 18 - 20, 2006, San Francisco, California, U.S.A. Y1 - 2006 SN - 978-1-55899-867-4 SP - 353 EP - 358 PB - Materials Research Society CY - Warrendale, Pa. 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 - 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 - GEN A1 - Müller, Klaus A1 - Goryachko, Andriy A1 - Burkov, Yevgen A1 - Schwiertz, Carola A1 - Ratzke, Markus A1 - Köble, J. A1 - Reif, Jürgen A1 - Schmeißer, Dieter T1 - Scanning Kelvin Probe Microscopy and Photoemission electron microscopy of organic source-drain structures T2 - Synthetic Metals N2 - n order to optimize organic field effect transistors (OFETs), the characterisation of active-layer surfaces in terms of their roughness, chemical composition and distribution of surface potentials is important. We report on high-resolution microscopic mapping of organic source-drain structures with P3HT as the semiconductor by scanning Kelvin probe microscopy (SKPM) and photoemission electron microscopy (PEEM). It was shown that PEEM is able to characterise the surface morphology (roughness), the chemical homogeneity and the composition of organic structures. The two-dimensional mapping of surface potentials by SKPM with applied source-drain voltages is shown to be an important ingredient of OFETs failure mode analysis. KW - Photoemission electron microscopy (PEEM) KW - Scanning Kelvin probe microscopy (SKPM) KW - OFET Y1 - 2004 SN - 0379-6779 VL - 146 IS - 3 SP - 377 EP - 382 ER - TY - CHAP A1 - Müller, Klaus A1 - Bär, Werner A1 - Henkel, Karsten A1 - Jahnke, Agnes A1 - Schwiertz, Carola A1 - Schmeißer, Dieter T1 - Organische Feldeffekttransistoren als Transducer in der Biosensorik Y1 - 2003 SN - 3-935712-92-8 SP - 119 EP - 223 PB - w.e.b.-Univ.-Verl. CY - Dresden ER - TY - CHAP A1 - Henkel, Karsten A1 - Schwiertz, Carola A1 - Wagner, S. A1 - Valdeig, A. A1 - List, M. A1 - Schmeißer, Dieter T1 - Partikel- und Tropfendetektion im Mikrometerbereich mittels Schwingquarzen Y1 - 2003 SN - 3-935712-92-8 SP - 291 EP - 294 PB - w.e.b.-Univ.-Verl. CY - Dresden ER - TY - GEN A1 - Müller, Klaus A1 - Bär, Werner A1 - Henkel, Karsten A1 - Jahnke, Agnes A1 - Schwiertz, Carola A1 - Schmeißer, Dieter T1 - Organische Feldeffekttransistoren als Transducer in der Biosensorik T1 - Organic Field Effect Transistors as Biosensors T2 - Technisches Messen N2 - In diesem Beitrag wird der Einsatz neuartiger Sensortypen für die medizinische Diagnostik beschrieben. Diese Sensoren sollen komplett organisch sein und auf dem Prinzip des Feldeffekttransistors basieren. Als Modellsystem für die Anwendung in der Biosensorik soll die Einsatzmöglichkeit dieser Sensoren in der nicht-invasiven Diagnostik der Helicobacter-pylori-Infektion überprüft werden. N2 - In this contribution we describe the investigation of new types of sensors in medical diagnosis. These sensors are completely organic and are based on the principle of organic field effect transistors. As model system for application in medical diagnosis we test the usability of this sensors for the diagnosis of helicobacter pylori. KW - Feldeffekttransistor KW - Biosensorik KW - Helicobacter pylori KW - Field effect transistors KW - biosensors KW - helicobacter pylori Y1 - 2003 U6 - https://doi.org/10.1524/teme.70.12.565.20261 SN - 0171-8096 VL - 70 IS - 12 SP - 565 EP - 568 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 -