TY - GEN A1 - Koval, Yuri A1 - Lazareva, I. A1 - Müller, P. A1 - Müller, Klaus A1 - Henkel, Karsten A1 - Friedrich, Daniel T1 - Field effect transistors on graphitized polymer surfaces KW - transistors KW - polymer Y1 - 2011 ER - TY - GEN A1 - Decker, Daniel A1 - Kusterle, O. A1 - Bauer, Monika A1 - Gwiazda, Maciej A1 - Müller, R. T1 - New Organic-Inorganic Hybrid Resins for RTM Y1 - 2009 ER - TY - CHAP A1 - Bauer, Monika A1 - Gwiazda, Maciej A1 - Müller, Ralf A1 - Decker, Daniel T1 - RTM-Materials Based on Silazane-Resin-Systems T2 - Proceedings, 7th International Conference on High Temperature Ceramic Matrix Composites (HT-CMC 7), September 20 - 22, 2010 in Bayreuth KW - new generation of RTM-resins KW - RTM KW - hybrid resins Y1 - 2010 PB - AVISO Verl.-Ges. CY - Berlin ER - TY - GEN A1 - Zellmann, Ingolf A1 - Schimmelpfeng, Katja A1 - Krüger, Ute A1 - Müller, Mario A1 - Sievers, Daniel A1 - Hackstein, Achim T1 - Die Leitstelle: Der Notrufdialog ist der Kernprozess Y1 - 2011 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 - 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 - Michling, Marcel A1 - Friedrich, Daniel A1 - Schmeißer, Dieter A1 - Koval, Yuri A1 - Müller, Paul T1 - Study of polyimide after graphitization with low-energy Ar+ Ion irradiation by NEXAFS T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44 N2 - In this contribution we report on investigations of the electronic structure of Ar+ irradiated polyimide samples by using NEXAFS. The NEXAFS measurements were done at the U49/2-PGM2 beam line of BESSY II, Berlin using TEY and TFY detection. Polyimide samples are prepared using low Ar+ dose while the temperature of the samples is varied between 300K and 700K. In the NEXAFS data at the Carbon K-edge we see substantial changes between different samples. The differences appear in particular in the more surface sensitive TEY-Signal. The NEXFS data are consistent with the graphitization of the surface upon Ar+ bombardment as we identify the characteristic absorption bands of graphitic carbon. Its relative content increases with increasing sample temperature. In contrast, in the more bulk sensitive TFY data, the emission characteristic of polyimide is maintained. The possibility to cover insulating polymers with a conducting layer is a great demand for many applications. Because of the relative low price of the basic materials, the irradiation with low-energy Ions will play an important roll in the microelectronic of the future. Y1 - 2009 UR - http://www.dpg-verhandlungen.de/year/2009/conference/dresden/part/df/session/15/contribution/5 SN - 0420-0195 SP - S. 147 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Friedrich, Daniel A1 - Michling, Marcel A1 - Schmeißer, Dieter A1 - Koval, Yuri A1 - Müller, Paul T1 - Characterization of ion beam modified polyimide layers T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45 N2 - Ion beam modified polyimide show high conductivity. In our investigation we focus on the electronic structure and the element composition, in order to understand the mechanism of conductivity. In our experiments we use the methods NEXAFS and PES. The measurements were done at the U49/2-PGM2 beam line of BESSY II, Berlin. We find an increase of the sp2 hybridized graphite contribution, after low Ar+ ion doses bombardment while the temperature of the samples is varied from 300 K to 650 K. In addition we follow the He+ bombardment induced changes by in-situ monitoring of the O1s, N1s content in the polyimide films. Y1 - 2010 UR - http://www.dpg-verhandlungen.de/year/2010/conference/regensburg/part/ds/session/38/contribution/10 SN - 0420-0195 SP - S. 247 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Friedrich, Daniel A1 - Koval, Yuri A1 - Müller, Paul A1 - Schmeißer, Dieter T1 - Electronic structure of thin spin-coated polyimide layers T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46 N2 - The conductivity of polyimide layers can be modified by several orders of magnitude by ion beam radiation. In order to understand the electronic structure of the pure polyimide before ion beam modification we focus in our preliminary experiments on spectroscopic investigations of thin as prepared polyimide films. The films were made by spin coating from a PMDA/ODA solution with subsequent vacuum annealing at 350°C. The layer thickness can be controlled by changing the concentration of PMDA/ODA in the solution realizing a thickness down to 3.5nm. For the characterization of the as prepared thin polyimide films the techniques NEXAFS, ResPES, XPS and CIS were applied at the U49/2-PGM2 beam line of Bessy II, Berlin. Our data including the valence band, core levels and absorption spectrum were compared with theoretical LCAO calculations. Based on these results we are able to attribute all spectral features to the specific atomic bonds in the molecule. Y1 - 2011 UR - http://www.dpg-verhandlungen.de/year/2011/conference/dresden/part/ds/session/63/contribution/3 SN - 0420-0195 SP - S. 311 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - GEN A1 - Cuypers, Daniel A1 - Fleischmann, Claudia A1 - Dorp, Dennis H. von A1 - Brizzi, Simone A1 - Tallarida, Massimo A1 - Müller, Matthias A1 - Hönicke, Philipp A1 - Billen, Arne A1 - Chintala, Ravi A1 - Conard, Thierry A1 - Schmeißer, Dieter A1 - Vandervorst, Wilfried A1 - Elshocht, Sven van A1 - Armini, Silvia A1 - De Gendt, Stefan A1 - Adelmann, Christoph T1 - Sacrificial Self-Assembled Monolayers for the Passivation of GaAs(100) Surfaces and Interfaces T2 - Chemistry of Materials N2 - The use of sacrificial self-assembled monolayers (SAMs) to prepare clean n-type GaAs (100) surfaces without band bending in vacuo is demonstrated. GaAs surface passivation using octadecanethiol SAMs after HCl cleaning is shown to lead to an enhancement of the room-temperature photoluminescence intensity. Synchrotron-radiation photoelectron spectroscopy (SRPES) finds that the interfacial oxide between GaAs and the SAM remains below the detection limit. Evidence for both Ga–S and As–S bonds at the GaAs–thiolate interface is found. The limited thermal stability of the SAM allows the desorption of the alkyl chains by in situ thermal annealing at temperatures above 180 °C, leaving S bonded to Ga behind. The resulting surface contains only a very small amount of O (0.05 ML coverage) and C (about 3% of the SAM remaining) and shows no band bending with the surface Fermi level close to the conduction band. Atomic layer deposition of Al₂O₃ on this surface occurs via the formation of Al–S bonds without introducing any additional band bending. This indicates that the surface preparation of n-type GaAs (100) using sacrificial octadecanethiol SAMs followed by in situ thermal removal provides a route toward GaAs/oxide interfaces without interfacial oxides and without band bending. KW - GaAs KW - passivation KW - Al₂O₃ KW - atomic layer deposition (ALD) KW - Synchrotron-radiation photoelectron spectroscopy (SRPES) KW - self assembled monolayers (SAM) KW - interface engineering Y1 - 2016 U6 - https://doi.org/10.1021/acs.chemmater.6b01732 SN - 0897-4756 SN - 1520-5002 VL - 28 IS - 16 SP - 5689 EP - 5701 ER - TY - GEN A1 - Boch, Steffen A1 - Allan, Eric A1 - Birkhofer, Klaus A1 - Bossdorf, Oliver A1 - Blüthgen, Nico A1 - Christ-Breulmann, Sabina A1 - Diekötter, Tim A1 - Dormann, Carsten F. A1 - Gossner, Martin M. A1 - Hallmann, Christine A1 - Hemp, Andreas A1 - Hölzel, Norbert A1 - Jung, Kirsten A1 - Klaus, Valentin H. A1 - Klein, Alexandra M. A1 - Kleinebecker, Till A1 - Lange, Markus A1 - Müller, Jörg A1 - Nacke, Heiko A1 - Prati, Daniel A1 - Renner, Swen C. A1 - Rothenwöhrer, Christoph A1 - Schall, Peter A1 - Schulze, Ernst-Detlef A1 - Socher, Stephanie A. A1 - Tscharntke, Teja A1 - Türke, Manfred A1 - Weiner, Christiane N. A1 - Weisser, Wolfgang W. A1 - Westphal, Catrin A1 - Wolters, Volkmar A1 - Wubet, Tesfaye A1 - Fischer, Markus T1 - Extensive und jährlich wechselnde Nutzungsintensität fördert den Artenreichtum im Grünland T2 - ANLIEGEN NATUR Y1 - 2016 UR - https://www.biom.uni-freiburg.de/mitarbeiter/dormann/boch2016anliegennatur.pdf SN - 1864-0729 VL - 38 IS - 1 SP - 86 EP - 95 ER - TY - GEN A1 - Dorp, Dennis H. von A1 - Nyns, Laura A1 - Cuypers, Daniel A1 - Ivanov, Tsvetan A1 - Brizzi, Simone A1 - Tallarida, Massimo A1 - Fleischmann, Claudia A1 - Hönicke, Philipp A1 - Müller, Matthias A1 - Richard, Olivier A1 - Schmeißer, Dieter A1 - De Gendt, Stefan A1 - Lin, Dennis H. C. A1 - Adelmann, Christoph T1 - Amorphous Gadolinium Aluminate as a Dielectric and Sulfur for Indium Phosphide Passivation T2 - ACS Applied Electronic Materials N2 - The passivation of n-type InP (100) using sulfur in combination with a gadolinium aluminate (GAO) dielectric layer has been studied. Photoluminescence, minority-carrier lifetime, and capacitance−voltage measurements indicate that a (NH4)2S vapor passivation step prior to atomic layer deposition of the oxide effectively lowers the interface state density. Surface and interface chemistry were studied by synchrotron radiation photoemission spectroscopy (SRPES). The effect of ex situ surface passivation after native oxide removal in HCl solution was examined. It was observed that surface reoxidation occurred during (NH4)2S vapor exposure, leading to the formation of Inx(HPO4)y. S was present on the surface as a sulfide in both surface and subsurface sites. After atomic layer deposition of GAO, sulfates were detected in addition to Inx(HPO4)y, which was confirmed by near-edge X-ray absorptionfine structure analysis. The S in the stack was quantified using reference-free grazing incidence X-rayfluorescence analysis. X-ray absorption spectroscopy showed that Gd was oxidized and present in the 3+ oxidation state, most likely as a phosphate close to the InP interface and possibly mixed with sulfates. Energy-dependent SRPES measurements of Al 2p and Gd 4d core levels, complemented by transmission electron microscopy, further suggest that the dielectric layer was segregated. Valence band measurements confirm the effective passivation of InP, indicating unpinning of the surface Fermi level. KW - III−V KW - InP KW - sulfur passivation KW - atomic layer deposition KW - gadolinium aluminate KW - rare earth oxide KW - dielectric Y1 - 2019 U6 - https://doi.org/10.1021/acsaelm.9b00388 SN - 2637-6113 VL - 1 IS - 11 SP - 2190 EP - 2201 ER - TY - GEN A1 - Caviedes-Voullième, Daniel A1 - Gerhard, Nils A1 - Sikstel, Aleksey A1 - Müller, Siegfried T1 - Multiwavelet-based mesh adaptivity with Discontinuous Galerkin schemes: Exploring 2D shallow water problems T2 - Advances in Water Resources N2 - In Gerhard et al. (2015a) a new class of adaptive Discontinuous Galerkin schemes has been introduced for shallow water equations, including the particular necessary properties, such as well-balancing and wetting-drying treatments. The adaptivity strategy is based on multiresolution analysis using multiwavelets in order to encode information across different mesh resolution levels. In this work, we follow-up on the previous proof-of-concept to thoroughly explore the performance, capabilities and weaknesses of the adaptive numerical scheme in the two-dimensional shallow water setting, under complex and realistic problems. To do so, we simulate three well-known and frequently used experimental benchmark tests in the context of flood modelling, ranging from laboratory to field scale. The real and complex topographies result in complex flow fields which pose a greater challenge to the adaptive numerical scheme and are computationally more ambitious, thus requiring a parallelised version of the aforementioned scheme. The benchmark tests allow to examine in depth the resulting adaptive meshes and the hydrodynamic performance of the scheme. We show that the scheme presented by Gerhard et al. (2015a) is accurate, i.e., allows to capture simultaneously large and very small flow structures, is robust, i.e., local grid refinement is controlled by just one parmeter that is auotmatically chosen and is more efficient in terms of the adaptive meshes than other shallow-water adaptive schemes achieving higher resolution with less cells. KW - Dynamic adaptive meshing KW - Multiresolution analysis KW - High-order schemes KW - Shallow water equation KW - Discontinuous Galerkin KW - Multiwavelets Y1 - 2020 UR - http://www.sciencedirect.com/science/article/pii/S0309170819309121 U6 - https://doi.org/10.1016/j.advwatres.2020.103559 SN - 0309-1708 VL - 138 ER - TY - GEN A1 - Caviedes-Voullième, Daniel A1 - Gerhard, Nils A1 - Sikstel, Aleksey A1 - Müller, Siegfried T1 - Adaptive 2D shallow water simulation based on a MultiWavelet Discontinous Galerkin approach T2 - EGU General Assembly 2020, Online, 4–8 May 2020 Y1 - 2020 U6 - https://doi.org/10.5194/egusphere-egu2020-14464 ER - TY - RPRT A1 - Thonicke, Kirsten A1 - Rahner, Eva A1 - Arneth, Almut A1 - Bartkowski, Bartosz A1 - Bonn, Aletta A1 - Döhler, Christian A1 - Finger, Robert A1 - Freitag, Jens A1 - Grosch, Rita A1 - Grossart, Hans-Peter A1 - Grützmacher, Kim A1 - Hartman Scholz, Amber A1 - Häuser, Christoph A1 - Hickler, Thomas A1 - Hölker, Franz A1 - Jähnig, Sonja C. A1 - Jeschke, Jonathan A1 - Kassen, Rees A1 - Kastner, Thomas A1 - Kramer-Schadt, Stephanie A1 - Krug, Cornelia A1 - Lakner, Sebastian A1 - Loft, Lasse A1 - Matzdorf, Bettina A1 - Meakins, Felicity A1 - De Meester, Luc A1 - Monaghan, Michael T. A1 - Müller, Daniel A1 - Overmann, Jörg A1 - Quaas, Martin A1 - Radchuk, Viktoriia A1 - Reyer, Christopher A1 - Roos, Christian A1 - Scholz, Imme A1 - Schroer, Sibylle A1 - Sioen, Giles Bruno A1 - Sommer, Simone A1 - Sommerwerk, Nike A1 - Tockner, Klement A1 - Turk, Zachary A1 - Warner, Barbara A1 - Wätzold, Frank A1 - Wende, Wolfgang A1 - Veenstra, Tonjes A1 - Voort, Hein van de T1 - 10 Must-Knows aus der Biodiversitätsforschung Y1 - 2022 U6 - https://doi.org/10.5281/zenodo.6257476 PB - Potsdam-Institut für Klimafolgenforschung e.V. (PIK) CY - Potsdam ER - TY - GEN A1 - Eisenhauer, Nico A1 - Frank, Karin A1 - Weigelt, Alexandra A1 - Bartkowski, Bartosz A1 - Beugnon, Rémy A1 - Liebal, Katja A1 - Mahecha, Miguel A1 - Quaas, Martin A1 - Al‐Halbouni, Djamil A1 - Bastos, Ana A1 - Bohn, Friedrich J. A1 - Brito, Mariana Madruga de A1 - Denzler, Joachim A1 - Feilhauer, Hannes A1 - Fischer, Rico A1 - Fritsche, Immo A1 - Guimaraes‐Steinicke, Claudia A1 - Hänsel, Martin A1 - Haun, Daniel B. M. A1 - Herrmann, Hartmut A1 - Huth, Andreas A1 - Kalesse‐Los, Heike A1 - Koetter, Michael A1 - Kolleck, Nina A1 - Krause, Melanie A1 - Kretschmer, Marlene A1 - Leitão, Pedro J. A1 - Masson, Torsten A1 - Mora, Karin A1 - Müller, Birgit A1 - Peng, Jian A1 - Pöhlker, Mira L. A1 - Ratzke, Leonie A1 - Reichstein, Markus A1 - Richter, Solveig A1 - Rüger, Nadja A1 - Sánchez‐Parra, Beatriz A1 - Shadaydeh, Maha A1 - Sippel, Sebastian A1 - Tegen, Ina A1 - Thrän, Daniela A1 - Umlauft, Josefine A1 - Wendisch, Manfred A1 - Wolf, Kevin A1 - Wirth, Christian A1 - Zacher, Hannes A1 - Zaehle, Sönke A1 - Quaas, Johannes T1 - A belowground perspective on the nexus between biodiversity change, climate change, and human well‐being T2 - Journal of Sustainable Agriculture and Environment N2 - Soil is central to the complex interplay among biodiversity, climate, and society. This paper examines the interconnectedness of soil biodiversity, climate change, and societal impacts, emphasizing the urgent need for integrated solutions. Human‐induced biodiversity loss and climate change intensify environmental degradation, threatening human well‐being. Soils, rich in biodiversity and vital for ecosystem function regulation, are highly vulnerable to these pressures, affecting nutrient cycling, soil fertility, and resilience. Soil also crucially regulates climate, influencing energy, water cycles, and carbon storage. Yet, climate change poses significant challenges to soil health and carbon dynamics, amplifying global warming. Integrated approaches are essential, including sustainable land management, policy interventions, technological innovations, and societal engagement. Practices like agroforestry and organic farming improve soil health and mitigate climate impacts. Effective policies and governance are crucial for promoting sustainable practices and soil conservation. Recent technologies aid in monitoring soil biodiversity and implementing sustainable land management. Societal engagement, through education and collective action, is vital for environmental stewardship. By prioritizing interdisciplinary research and addressing key frontiers, scientists can advance understanding of the soil biodiversity–climate change–society nexus, informing strategies for environmental sustainability and social equity. Y1 - 2024 U6 - https://doi.org/10.1002/sae2.12108 SN - 2767-035X VL - 3 IS - 2 PB - Wiley ER -