@misc{KovalLazarevaMuelleretal., author = {Koval, Yuri and Lazareva, I. and M{\"u}ller, P. and M{\"u}ller, Klaus and Henkel, Karsten and Friedrich, Daniel}, title = {Field effect transistors on graphitized polymer surfaces}, language = {en} } @inproceedings{BauerGwiazdaMuelleretal., author = {Bauer, Monika and Gwiazda, Maciej and M{\"u}ller, Ralf and Decker, Daniel}, title = {RTM-Materials Based on Silazane-Resin-Systems}, series = {Proceedings, 7th International Conference on High Temperature Ceramic Matrix Composites (HT-CMC 7), September 20 - 22, 2010 in Bayreuth}, booktitle = {Proceedings, 7th International Conference on High Temperature Ceramic Matrix Composites (HT-CMC 7), September 20 - 22, 2010 in Bayreuth}, publisher = {AVISO Verl.-Ges.}, address = {Berlin}, language = {en} } @misc{ZellmannSchimmelpfengKruegeretal., author = {Zellmann, Ingolf and Schimmelpfeng, Katja and Kr{\"u}ger, Ute and M{\"u}ller, Mario and Sievers, Daniel and Hackstein, Achim}, title = {Die Leitstelle: Der Notrufdialog ist der Kernprozess}, language = {de} } @inproceedings{RichterFriedrichPhilipetal., author = {Richter, Matthias and Friedrich, Daniel and Philip, Shine and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Study of P3HT/PCBM based films by NEXAFS}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 194}, abstract = {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.}, language = {en} } @techreport{ThonickeRahnerArnethetal., author = {Thonicke, Kirsten and Rahner, Eva and Arneth, Almut and Bartkowski, Bartosz and Bonn, Aletta and D{\"o}hler, Christian and Finger, Robert and Freitag, Jens and Grosch, Rita and Grossart, Hans-Peter and Gr{\"u}tzmacher, Kim and Hartman Scholz, Amber and H{\"a}user, Christoph and Hickler, Thomas and H{\"o}lker, Franz and J{\"a}hnig, Sonja C. and Jeschke, Jonathan and Kassen, Rees and Kastner, Thomas and Kramer-Schadt, Stephanie and Krug, Cornelia and Lakner, Sebastian and Loft, Lasse and Matzdorf, Bettina and Meakins, Felicity and De Meester, Luc and Monaghan, Michael T. and M{\"u}ller, Daniel and Overmann, J{\"o}rg and Quaas, Martin and Radchuk, Viktoriia and Reyer, Christopher and Roos, Christian and Scholz, Imme and Schroer, Sibylle and Sioen, Giles Bruno and Sommer, Simone and Sommerwerk, Nike and Tockner, Klement and Turk, Zachary and Warner, Barbara and W{\"a}tzold, Frank and Wende, Wolfgang and Veenstra, Tonjes and Voort, Hein van de}, title = {10 Must-Knows aus der Biodiversit{\"a}tsforschung}, publisher = {Potsdam-Institut f{\"u}r Klimafolgenforschung e.V. (PIK)}, address = {Potsdam}, doi = {10.5281/zenodo.6257476}, pages = {58}, language = {de} } @misc{DorpNynsCuypersetal., author = {Dorp, Dennis H. von and Nyns, Laura and Cuypers, Daniel and Ivanov, Tsvetan and Brizzi, Simone and Tallarida, Massimo and Fleischmann, Claudia and H{\"o}nicke, Philipp and M{\"u}ller, Matthias and Richard, Olivier and Schmeißer, Dieter and De Gendt, Stefan and Lin, Dennis H. C. and Adelmann, Christoph}, title = {Amorphous Gadolinium Aluminate as a Dielectric and Sulfur for Indium Phosphide Passivation}, series = {ACS Applied Electronic Materials}, volume = {1}, journal = {ACS Applied Electronic Materials}, number = {11}, issn = {2637-6113}, doi = {10.1021/acsaelm.9b00388}, pages = {2190 -- 2201}, abstract = {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.}, language = {en} } @misc{CuypersFleischmannDorpetal., author = {Cuypers, Daniel and Fleischmann, Claudia and Dorp, Dennis H. von and Brizzi, Simone and Tallarida, Massimo and M{\"u}ller, Matthias and H{\"o}nicke, Philipp and Billen, Arne and Chintala, Ravi and Conard, Thierry and Schmeißer, Dieter and Vandervorst, Wilfried and Elshocht, Sven van and Armini, Silvia and De Gendt, Stefan and Adelmann, Christoph}, title = {Sacrificial Self-Assembled Monolayers for the Passivation of GaAs(100) Surfaces and Interfaces}, series = {Chemistry of Materials}, volume = {28}, journal = {Chemistry of Materials}, number = {16}, issn = {0897-4756}, doi = {10.1021/acs.chemmater.6b01732}, pages = {5689 -- 5701}, abstract = {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.}, language = {en} } @misc{MuellerRichterFriedrichetal., author = {M{\"u}ller, Klaus and Richter, Matthias and Friedrich, Daniel and Paloumpa, Ioanna and Kramm, Ulrike Ingrid and Schmeißer, Dieter}, title = {Spectroscopic characterization of Cobalt-Phthalocyanine electrocatalysts for fuel cell applications}, series = {Solid State Ionics}, journal = {Solid State Ionics}, number = {216}, issn = {1872-7689}, doi = {10.1016/j.ssi.2011.12.013}, pages = {78 -- 82}, abstract = {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.}, language = {en} } @inproceedings{FriedrichKovalMuelleretal., author = {Friedrich, Daniel and Koval, Yuri and M{\"u}ller, Paul and Schmeißer, Dieter}, title = {Electronic structure of thin spin-coated polyimide layers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 46}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 311}, abstract = {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.}, language = {en} } @inproceedings{PhilipRichterFriedrichetal., author = {Philip, Shine and Richter, Matthias and Friedrich, Daniel and Paloumpa, Ioanna and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Spectroscopic investigations of P3HT/PCBM films for organic BHJ solar cells}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 153}, abstract = {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.}, language = {en} } @inproceedings{FriedrichMichlingSchmeisseretal., author = {Friedrich, Daniel and Michling, Marcel and Schmeißer, Dieter and Koval, Yuri and M{\"u}ller, Paul}, title = {Characterization of ion beam modified polyimide layers}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 247}, abstract = {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.}, language = {en} } @inproceedings{MichlingFriedrichSchmeisseretal., author = {Michling, Marcel and Friedrich, Daniel and Schmeißer, Dieter and Koval, Yuri and M{\"u}ller, Paul}, title = {Study of polyimide after graphitization with low-energy Ar+ Ion irradiation by NEXAFS}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 147}, abstract = {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.}, language = {en} } @misc{CaviedesVoulliemeGerhardSiksteletal., author = {Caviedes-Voulli{\`e}me, Daniel and Gerhard, Nils and Sikstel, Aleksey and M{\"u}ller, Siegfried}, title = {Adaptive 2D shallow water simulation based on a MultiWavelet Discontinous Galerkin approach}, series = {EGU General Assembly 2020, Online, 4-8 May 2020}, journal = {EGU General Assembly 2020, Online, 4-8 May 2020}, doi = {10.5194/egusphere-egu2020-14464}, language = {en} } @misc{CaviedesVoulliemeGerhardSiksteletal., author = {Caviedes-Voulli{\`e}me, Daniel and Gerhard, Nils and Sikstel, Aleksey and M{\"u}ller, Siegfried}, title = {Multiwavelet-based mesh adaptivity with Discontinuous Galerkin schemes: Exploring 2D shallow water problems}, series = {Advances in Water Resources}, volume = {138}, journal = {Advances in Water Resources}, issn = {0309-1708}, doi = {10.1016/j.advwatres.2020.103559}, pages = {29}, abstract = {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.}, language = {en} } @misc{DeckerKusterleBaueretal., author = {Decker, Daniel and Kusterle, O. and Bauer, Monika and Gwiazda, Maciej and M{\"u}ller, R.}, title = {New Organic-Inorganic Hybrid Resins for RTM}, language = {en} } @misc{BochAllanBirkhoferetal., author = {Boch, Steffen and Allan, Eric and Birkhofer, Klaus and Bossdorf, Oliver and Bl{\"u}thgen, Nico and Christ-Breulmann, Sabina and Diek{\"o}tter, Tim and Dormann, Carsten F. and Gossner, Martin M. and Hallmann, Christine and Hemp, Andreas and H{\"o}lzel, Norbert and Jung, Kirsten and Klaus, Valentin H. and Klein, Alexandra M. and Kleinebecker, Till and Lange, Markus and M{\"u}ller, J{\"o}rg and Nacke, Heiko and Prati, Daniel and Renner, Swen C. and Rothenw{\"o}hrer, Christoph and Schall, Peter and Schulze, Ernst-Detlef and Socher, Stephanie A. and Tscharntke, Teja and T{\"u}rke, Manfred and Weiner, Christiane N. and Weisser, Wolfgang W. and Westphal, Catrin and Wolters, Volkmar and Wubet, Tesfaye and Fischer, Markus}, title = {Extensive und j{\"a}hrlich wechselnde Nutzungsintensit{\"a}t f{\"o}rdert den Artenreichtum im Gr{\"u}nland}, series = {ANLIEGEN NATUR}, volume = {38}, journal = {ANLIEGEN NATUR}, number = {1}, issn = {1864-0729}, pages = {86 -- 95}, language = {de} }