@incollection{SchwiertzHenkelPaloumpaetal., author = {Schwiertz, Carola and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter}, title = {Sensorsystem zur Unterscheidung von Geruchsmustern in Tierst{\"a}llen}, abstract = {Es wurde ein kontinuierlich arbeitendes, preiswertes Schwingquarz-Mess-System zur olfaktometrischen {\"U}berwachung von Tierst{\"a}llen aufgebaut, mit dessen Hilfe im Arbeitsbereich von 65\%B0C spezifische Ger{\"u}che verschiedener Tierarten unterschieden werden k{\"o}nnen. Zur Geruchsmustererkennung wurde ein einfaches neuronales Netz verwendet. Olfaktometrische Verd{\"u}nnungen auf 33\% sowie Messwertschwankungen von 5-10\% wurden simuliert, wobei die richtige Musterzuordnung durch das Netz nicht beeinflusst wurde.}, language = {de} } @incollection{MuellerBaerHenkeletal., author = {M{\"u}ller, Klaus and B{\"a}r, Werner and Henkel, Karsten and Jahnke, Agnes and Schwiertz, Carola and Schmeißer, Dieter}, title = {Organische Feldeffekttransistoren als Transducer in der Biosensorik}, publisher = {w.e.b.-Univ.-Verl.}, address = {Dresden}, isbn = {3-935712-92-8}, pages = {119 -- 223}, language = {de} } @misc{MuellerGoryachkoBurkovetal., author = {M{\"u}ller, Klaus and Goryachko, Andriy and Burkov, Yevgen and Schwiertz, Carola and Ratzke, Markus and K{\"o}ble, J. and Reif, J{\"u}rgen and Schmeißer, Dieter}, title = {Scanning Kelvin Probe Microscopy and Photoemission electron microscopy of organic source-drain structures}, series = {Synthetic Metals}, volume = {146}, journal = {Synthetic Metals}, number = {3}, issn = {0379-6779}, pages = {377 -- 382}, abstract = {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.}, language = {en} } @incollection{HenkelSchwiertzWagneretal., author = {Henkel, Karsten and Schwiertz, Carola and Wagner, S. and Valdeig, A. and List, M. and Schmeißer, Dieter}, title = {Partikel- und Tropfendetektion im Mikrometerbereich mittels Schwingquarzen}, publisher = {w.e.b.-Univ.-Verl.}, address = {Dresden}, isbn = {3-935712-92-8}, pages = {291 -- 294}, language = {de} } @article{HenkelSohalSchmeisseretal., author = {Henkel, Karsten and Sohal, Rakesh and Schmeißer, Dieter and Schwiertz, Carola and Burkov, Yevgen and Torche, Mohamed}, title = {Al-oxynitride buffer layer facilities for PrOx/SiC interfaces}, language = {en} } @misc{HenkelTorcheSohaletal., author = {Henkel, Karsten and Torche, Mohamed and Sohal, Rakesh and Karavaev, Konstantin and Burkov, Yevgen and Schwiertz, Carola and Schmeißer, Dieter}, title = {Pr-O-Al-N dielectrics for metal insulator semiconductor stacks}, language = {en} } @incollection{SchwiertzHenkelBleietal., author = {Schwiertz, Carola and Henkel, Karsten and Blei, S. and Heidenreich, R. and Schmeißer, Dieter}, title = {Nachweis von Aerosolen (<1µm) mit Schwingquarzimpedanzspektroskopie}, language = {de} } @misc{HenkelBurkovKaravaevetal., author = {Henkel, Karsten and Burkov, Yevgen and Karavaev, Konstantin and Torche, Mohamed and Schwiertz, Carola and Schmeißer, Dieter}, title = {Optimization of the AION buffer layer for PrxOy/Si stacks}, language = {de} } @article{HenkelKaravaevTorcheetal., author = {Henkel, Karsten and Karavaev, Konstantin and Torche, Mohamed and Schwiertz, Carola and Burkov, Yevgen and Schmeißer, Dieter}, title = {Al-Oxyxynitride interfacial layer investigations for PrXOY on SiC and Si}, language = {en} } @inproceedings{HenkelTorcheSohaletal., author = {Henkel, Karsten and Torche, Mohamed and Sohal, Rakesh and Schwiertz, Carola and Hoffmann, Patrick and Schmeißer, Dieter}, title = {Pr-O-N Dielectrics for MIS Stacks on Silicon and Silicon Carbide Surfaces}, series = {Silicon carbide 2006 - materials, processing and devices, symposium held April 18 - 20, 2006, San Francisco, California, U.S.A.}, booktitle = {Silicon carbide 2006 - materials, processing and devices, symposium held April 18 - 20, 2006, San Francisco, California, U.S.A.}, editor = {Dudley, Michael}, publisher = {Materials Research Society}, address = {Warrendale, Pa.}, isbn = {978-1-55899-867-4}, pages = {353 -- 358}, language = {en} } @techreport{SchwiertzHenkelPaloumpaetal., author = {Schwiertz, Carola and Henkel, Karsten and Paloumpa, Ioanna and Schmeißer, Dieter and Kamieth, P. and Schnegber, P.}, title = {Aufbau eines Sensorarrays zur Detektion von umwelt- und tierphysiologisch relevanten Komponenten}, language = {de} } @inproceedings{HenkelSohalTorcheetal., author = {Henkel, Karsten and Sohal, Rakesh and Torche, Mohamed and Schwiertz, Carola and Burkov, Yevgen and Schmeißer, Dieter}, title = {PrOx/AlON stacks as a high-k candidate on SiC}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Bd. 42}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 215}, abstract = {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).}, language = {en} } @inproceedings{HenkelTorcheSchwiertzetal., author = {Henkel, Karsten and Torche, Mohamed and Schwiertz, Carola and Paloumpa, Ioanna and Sohal, Rakesh and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Inorganic and organic layers for high-k and organic memory applications}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 41}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 127}, abstract = {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.}, language = {en} } @inproceedings{IsraelRachowSchwiertzetal., author = {Israel, Johannes and Rachow, Fabian and Schwiertz, Carola and Charlafti, Evgenia and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Self restriction oft the Sabatier reaction in large scale}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {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.}, language = {en} } @inproceedings{RachowIsraelSchwiertzetal., author = {Rachow, Fabian and Israel, Johannes and Schwiertz, Carola and Charlafti, Evgenia and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {CO2 Methanation with different gas mixtures}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 539}, abstract = {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\%.}, language = {en} } @misc{MuellerGoryachkoBurkovetal., author = {M{\"u}ller, K. and Goryachko, Andriy and Burkov, Yevgen and Schwiertz, Carola and Ratzke, Markus and K{\"o}ble, J. and Reif, J{\"u}rgen and Schmeißer, Dieter}, title = {Scanning Kelvin probe and photoemission electron microscopy of organic source-drain structures}, series = {Synthetic Metals}, volume = {146}, journal = {Synthetic Metals}, number = {3}, pages = {377 -- 382}, language = {en} } @inproceedings{MuellerPaloumpaSchwiertzetal., author = {M{\"u}ller, Klaus and Paloumpa, Ioanna and Schwiertz, Carola and Jahnke, Agnes and Schmeißer, Dieter}, title = {All Polymer Field-Effect-Transistors based on Low-Cost-Microstructuring}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {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.}, language = {en} } @inproceedings{IsraelRachowSchwiertzetal., author = {Israel, Johannes and Rachow, Fabian and Schwiertz, Carola and Charlafti, Evgenia and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Direct CO2-Methanation of flue gas emitted by conventional power plants}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, pages = {S. 255}, abstract = {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.}, language = {en} } @misc{MuellerBaerHenkeletal., author = {M{\"u}ller, Klaus and B{\"a}r, Werner and Henkel, Karsten and Jahnke, Agnes and Schwiertz, Carola and Schmeißer, Dieter}, title = {Organische Feldeffekttransistoren als Transducer in der Biosensorik}, series = {Technisches Messen}, volume = {70}, journal = {Technisches Messen}, number = {12}, issn = {0171-8096}, doi = {10.1524/teme.70.12.565.20261}, pages = {565 -- 568}, abstract = {In diesem Beitrag wird der Einsatz neuartiger Sensortypen f{\"u}r die medizinische Diagnostik beschrieben. Diese Sensoren sollen komplett organisch sein und auf dem Prinzip des Feldeffekttransistors basieren. Als Modellsystem f{\"u}r die Anwendung in der Biosensorik soll die Einsatzm{\"o}glichkeit dieser Sensoren in der nicht-invasiven Diagnostik der Helicobacter-pylori-Infektion {\"u}berpr{\"u}ft werden.}, language = {de} } @misc{MuellerRachowIsraeletal., author = {M{\"u}ller, Klaus and Rachow, Fabian and Israel, Johannes and Charlafti, Evgenia and Schwiertz, Carola and Schmeißer, Dieter}, title = {Direct Methanation of Flue Gas at a Lignite Power Plant}, series = {International Journal of Environmental Science}, journal = {International Journal of Environmental Science}, number = {2}, issn = {2367-8941}, pages = {425 -- 437}, abstract = {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.}, language = {en} }