TY - GEN A1 - Schmeißer, Dieter A1 - Haeberle, Jörg A1 - Richter, Matthias A1 - Brazda, Petr T1 - Spin State and Satellite Structures of ε-Fe₂O₃ as determined by Resonant Photoelectron Spectroscopy T2 - Nuclear Instruments and Methods in Physics Research B N2 - We use resonant photoelectron spectroscopy at the Fe2p and the O1s absorption edges to report on spectroscopic investigation of Fe-oxides nanoparticles. We discuss the spectroscopic details like multiple Auger decays, satellite emission in the X-ray absorption process and the core level data. We explain these data by a novel mechanism in which the resonant excitation between Fe3d and Fe4s states are involved. This mechanism is observed when the photo-excited electron becomes polarized by the electron–hole pairs existing in the conduction and valence bands. KW - Resonant photoelectron spectroscopy KW - ε-Fe2O3nano particles KW - Satellite emission Y1 - 2015 U6 - https://doi.org/10.1016/j.nimb.2015.08.062 SN - 0168-583X VL - 2015 IS - 364 SP - 127 EP - 131 ER - TY - GEN A1 - Das, Chittaranjan A1 - Richter, Matthias A1 - Tallarida, Massimo A1 - Schmeißer, Dieter T1 - Electronic properties of atomic layer deposited films, anatase and rutile TiO2 studied by resonant photoemission spectroscopy T2 - Journal of Physics D: Applied Physics N2 - The TiO2 films are prepared by atomic layer deposition (ALD) method using titanium isopropoxide precursors at 250 °C and analyzed using resonant photoemission spectroscopy (resPES). We report on the Ti2p and O1s core levels, on the valence band (VB) spectra and x-ray absorption spectroscopy (XAS) data, and on the resonant photoelectron spectroscopy (resPES) profiles at the O1s and the Ti3p absorption edges. We determine the elemental abundance, the position of the VB maxima, the partial density of states (PDOS) in the VB and in the conduction band (CB) and collect these data in a band scheme. In addition, we analyze the band-gap states as well as the intrinsic states due to polarons and charge-transfer excitations. These states are found to cause multiple Auger decay processes upon resonant excitation. We identify several of these processes and determine their relative contribution to the Auger signal quantitatively. As our resPES data allow a quantitative analysis of these defect states, we determine the relative abundance of the PDOS in the VB and in CB and also the charge neutrality level. The anatase and rutile polymorphs of TiO2 are analyzed in the same way as the TiO2 ALD layer. The electronic properties of the TiO2ALD layer are compared with the anatase and rutile polymorphs of TiO2. In our comparative study, we find that ALD has its own characteristic electronic structure that is distinct from that of anatase and rutile. However, many details of the electronic structure are comparable and we benefit from our spectroscopic data and our careful analysis to find these differences. These can be attributed to a stronger hybridization of the O2p and Ti3d4s states for the ALD films when compared to the anatase and rutile polymorphs. KW - titanium dioxide (TiO2) KW - resonant photoemission spectroscopy (resPES) KW - defect states KW - partial density of states (pDOS) KW - charge neutrality level (CNL) Y1 - 2016 U6 - https://doi.org/10.1088/0022-3727/49/27/275304 SN - 0022-3727 SN - 1361-6463 VL - 49 IS - 27 SP - 275304-1 EP - 275304-17 ER - TY - CHAP A1 - Richter, Matthias A1 - Lichterman, Michael F. A1 - Hu, Shu A1 - Crumlin, Ethan J. A1 - Axnanda, Stephanus A1 - Favaro, Marco A1 - Drisdell, Walter S. A1 - Hussain, Zahid A1 - Brunschwig, Bruce S. A1 - Liu, Zhi A1 - Lewis, Nathan S. A1 - Lewerenz, Hans-Joachim T1 - Experimental Approach for Determining Semiconductor/liquid Junction Energetics by Operando Ambient Pressure X-ray Photoelectron Spectroscopy T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - The performance of a photoelectrochemical solar cell depends strongly on the electrochemical nature of the semiconductor/electrolyte junction [1]. Operando Ambient Pressure X-ray photoelectron spectroscopy investigation of semiconductor/liquid junctions provides quantitative understanding of the energy bands in these photoelectrochemical solar cells [2, 3, 4]. We demonstrate how OAP-XPS may be used to determine these relationships for semiconductor/liquid systems. The data can be analyzed to determine the energy relationship between the electronic energy bands in the semiconductor electrode and the redox levels in the solution. The major conditions for semiconductor-electrolyte contacts including accumulation, depletion, and Fermi-level pinning are observed, and the so-called flat-band energy can be determined. [1] Science 344 (2014) 1005; [2] Sci Rep 5 (2015) 9788; [3] Ener Sci 8 (2015) 2409; [4] J Electrochem Soc 162 (2016) H1 KW - in operando KW - ambient pressure spectroscopy KW - water splitting Y1 - 2016 UR - http://www.dpg-verhandlungen.de/year/2016/conference/regensburg/part/o/session/72/contribution/10?lang=en SP - S. 409 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Lichterman, Michael F. A1 - Richter, Matthias A1 - Hu, Shu A1 - Crumlin, Ethan J. A1 - Axnanda, Stephanus A1 - Favaro, Marco A1 - Drisdell, Walter S. A1 - Hussain, Zahid A1 - Brunschwig, Bruce S. A1 - Liu, Zhi A1 - Lewis, Nathan S. A1 - Lewerenz, Hans-Joachim T1 - Probing the TiO2/Liquid Interface of a Photoelectrochemical Cell by X-Ray Photoelectron Spectroscopy T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - Amorphous TiO2 coatings can stabilize semiconductor photoanodes such as Si, GaAs, and GaP that are otherwise unstable in aqueous media [1]. Using tender X-rays with their substantially increased inelastic mean free scattering length of photoelectrons and using the classical three-electrode potentiostatic arrangement allows one to follow of the influence of the applied potentials on the semiconductor electrode energetics such as band bending and band edge shifts directly [2, 3]. The observed shifts in binding energy with respect to the applied potential have directly revealed rectifying junction behavior on semiconducting samples. Accumulation, depletion and Fermi level pinning were observed. Additionally, the non-linear response of the core level binding energies to changes in the applied electrode potential has revealed the influence of defect-derived electronic states on the Galvani potential across the complete cell. [1] Science 344 (2014) 1005; [2] Sci Rep 5 (2015) 9788; [3] Ener & Env Sci 8 (2015) 2409 KW - X-Ray photoelectron spectroscopy KW - phototanodes KW - TiO2 passivation KW - water splitting Y1 - 2016 UR - http://www.dpg-verhandlungen.de/year/2016/conference/regensburg/part/o/session/82/contribution/1?lang=en SP - S. 414 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Haeberle, Jörg A1 - Richter, Matthias A1 - Schmeißer, Dieter A1 - Galazka, Zbigniew A1 - Janowitz, Christoph T1 - Resonant Photoemission at the O1s threshold to characterize In2O3 single crystals T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - We report on spectroscopic investigations on In2O3 single crystals. We focus on the detailed analysis of the O1s resonance profile by resonant photoelectron spectroscopy (resPES). From these we analyze the electronic structure and assign the O2p- and In5sp state to build the valence band and the conduction band in different contributions, respectively. This is deduced from constant final state spectra on the O-KLL-Auger along the O K-edge and In M4,5-edge and a comparison to the corresponding X-ray absorption spectroscopy data. We also identify several types of defects. A broad band of oxygen derived defects is identified in the valence band and extends throughout the gap. Small polarons are attributed to cause an anti-resonance in the constant initial states around the O1s threshold. In addition, an Auger decay separated by the O-KLL is present at O-K resonance and indicates the existence of localized charge transfer states which involves In5sp states. Finally, we are able to distinguish two different oxygen species from the resPES data. One corresponds to theintrinsic In2O3 structure and the other is a non-corresponding species. KW - resonant photoelectron spectroscopy KW - In2O3 Y1 - 2013 UR - http://www.dpg-verhandlungen.de/year/2013/conference/regensburg/part/mm/session/15/contribution/57?lang=de PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Richter, Matthias A1 - Schmeißer, Dieter T1 - The Co2p spin and oxidation state in Co-PI catalysts T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - The electronic structure of cobalt based catalysts used for photocatalytic water splitting in solar cells is analyzed using synchrotron radiation photoelectron spectroscopy. The catalyst films are prepared by electrochemical deposition. We employ a X-ray photoelectron spectroscopy study to analyze the Co2p and O1s core levels, absorption edges and valence bands. We discuss our resonant data in terms of the partial density of states of the valence and conduction band. We find a difference in the Co oxidation state as a function of film thickness (deposited charge). From the relative amount of Co, O, K and P we favor the molecular cobaltate cluster-like structure as the structural motif of the Co-PI catalyst. Further, at resonant PES at the Co2p edge we find the Co2p partial DOS to exhibit no sharp features next to the VBM, instead there is a broad emission at around 6eV below EFerrmi. The former are found in LiCoO2 and other Co-oxide systems with a Co3+ ground state. We attribute such sharp features to the low spin (LS) configuration of Co3+ and deduce that in the Co catalysts there is no evidence for the corresponding LS contributions. Our data prove the Co2+ ground state and demonstrate that it is exclusively in the Co3d7 high spin state in the pristine catalyst films. KW - X-Ray photoelectron spectroscopy KW - resonant photoemission spectroscopy KW - cobalt based catalyst KW - water splitting Y1 - 2013 UR - http://www.dpg-verhandlungen.de/year/2013/conference/regensburg/part/ds/session/35/contribution/9?lang=de PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Richter, Matthias A1 - Lichterman, Michael F. A1 - Hu, Shu A1 - Crumlin, Ethan J. A1 - Axnanda, Stephanus A1 - Favaro, Marco A1 - Drisdell, Walter S. A1 - Hussain, Zahid A1 - Brunschwig, Bruce S. A1 - Liu, Zhi A1 - Lewis, Nathan S. A1 - Lewerenz, Hans-Joachim T1 - An Electrochemical, resonant Photoemission and Ambient Pressure-X-ray Photoelectron Spectroscopic Investigation of Si/TiO2/Ni/Electrolyte Interfaces T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft N2 - Photoelectrochemical cells based on semiconductor-liquid interfaces provide a method of converting solar energy to electricity or fuels. Recently, we have demonstrated operational systems that involved stabilized semiconductor-liquid junctions [1]. The electrical and spectroscopic properties of the TiO2/Ni protection layer system have been investigated in contact with electrolyte solutions [2, 3, 4]. From the response of the photoelectron binding energies to variations in applied potential the energetics of the solid/electrolyte interface are elucidated. The degree of conductivity depended on the chemical state of the Ni on the TiO2 surface. The combinations of these techniques provide a powerful tool for the investigation of hybrid electrode/solution contacts. [1] Science 344 (2014) 1005; [2] Sci Rep 5 (2015) 9788; [3] Ener & Env Sci 8 (2015) 2409; [4] J Electrochem Soc 162 (2016) H1 KW - resonant photoelectron spectroscopy KW - ambient pressure spectroscopy KW - water splitting Y1 - 2016 UR - http://www.dpg-verhandlungen.de/year/2016/conference/regensburg/part/o/session/82/contribution/2?lang=en SP - S. 414 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - CHAP A1 - Bilz, Ludwig A1 - Sudeck, Gorden A1 - Bucksch, Jens A1 - Klocke, Andreas A1 - Kolip, Petra A1 - Melzer, Wolfgang A1 - Ravens-Sieberer, Ulrike A1 - Richter, Matthias ED - Bilz, Ludwig ED - Sudeck, Gorden ED - Bucksch, Jens ED - Klocke, Andreas ED - Kolip, Petra ED - Melzer, Wolfgang ED - Ravens-Sieberer, Ulrike ED - Richter, Matthias T1 - Der vierte deutsche Jugendgesundheitssurvey „Health Behaviour in School-aged Children“ T2 - Schule und Gesundheit : Ergebnisse des WHO-Jugendgesundheitssurveys "Health behaviour in school-aged children" Y1 - 2016 SN - 978-3-7799-1991-9 SP - 7 EP - 15 PB - Beltz Juventa CY - Weinheim ER - TY - CHAP A1 - Bucksch, Jens A1 - Finne, Emily A1 - Gohres, Hannah A1 - Bilz, Ludwig A1 - Moor, Irene A1 - Richter, Matthias A1 - Kolip, Petra ED - Bilz, Ludwig ED - Sudeck, Gorden ED - Bucksch, Jens ED - Klocke, Andreas ED - Kolip, Petra ED - Melzer, Wolfgang ED - Ravens-Sieberer, Ulrike ED - Richter, Matthias T1 - Die Methodik des HBSC-Surveys 2013/14 T2 - Schule und Gesundheit : Ergebnisse des WHO-Jugendgesundheitssurveys "Health behaviour in school-aged children" Y1 - 2016 SN - 978-3-7799-1991-9 SP - 35 EP - 46 PB - Beltz Juventa CY - Weinheim ER - TY - GEN A1 - Moor, Irene A1 - Spallek, Jacob A1 - Richter, Matthias T1 - Explaining socioeconomic inequalities in self-rated health - A systematic review of the relative contribution of material, psychological and behavioural factors T2 - Journal of Epidemiology & Community Health Y1 - 2017 U6 - https://doi.org/10.1136/jech-2016-207589 SN - 1470-2738 VL - 71 IS - 6 ER - TY - GEN A1 - Moor, Irene A1 - Lampert, Thomas A1 - Rathmann, Katharina A1 - Kuntz, Benjamin A1 - Kolip, Petra A1 - Spallek, Jacob A1 - Richter, Matthias T1 - Explaining educational inequalities in adolescent life satisfaction: Do health behaviour and gender matter T2 - International Journal of Public Health Y1 - 2014 SN - 1661-8564 VL - 59 IS - 2 SP - 309 EP - 317 ER - TY - GEN A1 - Moor, Irene A1 - Rathmann, Katharina A1 - Stronks, Karien A1 - Levin, Kate A1 - Spallek, Jacob A1 - Richter, Matthias T1 - Psychosocial and behavioural factors in the explanation of socioeconomic inequalities in adolescent health. A multilevel analysis in 28 European and North American countries T2 - Journal of epidemiology and community health Y1 - 2014 U6 - https://doi.org/10.1136/jech-2014-203933 SN - 1470-2738 VL - 68 IS - 10 SP - 912 EP - 921 ER - TY - GEN A1 - Lampert, Thomas A1 - Richter, Matthias A1 - Schreiber, Sven A1 - Spallek, Jacob A1 - Dragano, Nico T1 - Soziale Ungleichheit und Gesundheit. Stand und Perspektiven der sozialepidemiologischen Forschung in Deutschland T2 - Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz Y1 - 2016 U6 - https://doi.org/10.1007/s00103-015-2275-6 SN - 1436-9990 SN - 1437-1588 VL - 59 IS - 2 SP - 153 EP - 165 ER - TY - CHAP A1 - Tschöpe, Constanze A1 - Duckhorn, Frank A1 - Blüthgen, Peter A1 - Richter, Christian A1 - Papsdorf, Gunther A1 - Wolff, Matthias T1 - Miniaturisiertes System zur intelligenten Signalverarbeitung T2 - DGZFP-Jahrestagung 2017, Zerstörungsfreie Materialprüfung, Koblenz, 22.-24.05.2017, Kurzfassungen der Vorträge und Posterbeiträge Y1 - 2017 UR - https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=0ahUKEwiOtpCM7-zUAhXBZ1AKHXMyBQYQFghDMAQ&url=https%3A%2F%2Fjahrestagung.dgzfp.de%2FPortals%2F151%2Fdownloads%2FKufa_alles_oP%2520-%2520GESAMT%2520-%2520ohne%2520Anzeigen.pdf%3Fver%3D2017-05-19-135955-633&usg=AFQjCNGFKZug7Xf1FFhVCqafxEFIyDEIeA&cad=rja SP - S. 192 PB - DGZIP CY - Berlin ER - TY - CHAP A1 - Henkel, Karsten A1 - Kot, Małgorzata A1 - Richter, Matthias A1 - Tallarida, Massimo A1 - Schmeißer, Dieter ED - Wandelt, Klaus T1 - An (In Situ)² Approach: ALD and resPES Applied to Al₂O₃, HfO₂, and TiO₂ Ultrathin Films T2 - Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry, Vol. 3.1 N2 - Oxide surface coatings are of importance in tailoring interface properties with respect to surface passivation, adjustment of surface potentials, or providing active centers for surface reactions. In this contribution, we report about surface coatings prepared by the atomic layer deposition (ALD) method. ALD is known for its conformal growth of ultrathin, dense films which exhibit a low concentration of pinholes. KW - Atomic layer deposition (ALD) KW - Resonant photoelectron spectroscopy (resPES) KW - Band scheme KW - Partial density of states (pDOS) KW - Intrinsic charges KW - Intrinsic defects KW - Aluminum oxide (Al₂O₃) KW - Hafnium oxide (HfO₂) KW - Titanium oxide(TiO₂) Y1 - 2018 SN - 978-0-12-809739-7 SN - 978-0-12-809894-3 U6 - https://doi.org/10.1016/B978-0-12-409547-2.13852-1 SP - 18 EP - 26 PB - Elsevier CY - Oxford ER - TY - GEN A1 - Brinkert, Katharina A1 - Richter, Matthias A1 - Akay, Ömer A1 - Liedtke, Janine A1 - Giersig, Michael A1 - Fountaine, Katherine T. A1 - Lewerenz, Hans-Joachim T1 - Efficient Solar Hydrogen Generation in Microgravity Environment T2 - Nature Communications N2 - Long-term space missions require extra-terrestrial production of storable, renewable energy. Hydrogen is ascribed a crucial role for transportation, electrical power and oxygen generation. We demonstrate in a series of drop tower experiments that efficient direct hydrogen production can be realized photoelectrochemically in microgravity environment, providing an alternative route to existing life support technologies for space travel. The photoelectrochemical cell consists of an integrated catalyst-functionalized semiconductor system that generates hydrogen with current densities >15 mA/cm2 in the absence of buoyancy. Conditions are described adverting the resulting formation of ion transport blocking froth layers on the photoelectrodes. The current limiting factors were overcome by controlling the micro- and nanotopography of the Rh electrocatalyst using shadow nanosphere lithography. The behaviour of the applied system in terrestrial and microgravity environment is simulated using a kinetic transport model. Differences observed for varied catalyst topography are elucidated, enabling future photoelectrode designs for use in reduced gravity environments. Y1 - 2018 U6 - https://doi.org/10.1038/s41467-018-04844-y SN - 2041-1723 IS - 9 ER - TY - GEN A1 - Rathmann, Katharina A1 - Bilz, Ludwig A1 - Hurrelmann, Klaus A1 - Kiess, Wieland A1 - Richter, Matthias T1 - Is being a “small fish in a big pond” bad for students´ psychosomatic health? A multilevel study on the role of class-level school performance T2 - BMC Public Health N2 - Background. Features of schools and classes are closely related to students´ health and wellbeing. However, class composition (e.g. in terms of school performance) has rarely been examined in relation to students´ health and wellbeing. This study focuses on the so called Big-Fish-Little-Pond-Effect (BFLPE), by investigating whether the level of high-performing students in classroom is negatively associated with psychosomatic complaints of students who perceive themselves as poor performers. Methods. Data were derived from the German sample of the WHO-Collaborative “Health Behaviour in School-aged Children (HBSC)” study 2013/2014. The sample included 5226 11-, 13- and 15-year-old students. Individual perceived school performance (PSP) was included (very good/good vs. average/below average PSP) at the individual student-level. At the class-level, school performance in class was generated by aggregating the share (in percentage) of students who report a very good/good PSP to the class-level, indicating the percentage of students with good/very good PSP in classroom. Using multilevel regression models, the association between class-level school performance (in percentage of students with very good/good PSP) and individual psychosomatic complaints were analyzed, stratified by students´ individual PSP. Results. Students who report average/below average PSP showed higher likelihoods of psychosomatic complaints (Odds Ratio: 1.75; 95% Confidence Interval: 1.52–2.03) compared to counterparts with very good/good PSP. The aggregated class-level PSP was not significantly associated with psychosomatic complaints. However, in line with the BFLPE, results further revealed that students with average/below average PSP, who attend classes with a higher percentage of students who report very good/good PSP, had higher likelihoods of psychosomatic complaints (Odds Ratio: 1.91; 95% Confidence Interval: 1.01–4.01) compared to classmates with very good/good PSP. Conclusions. This study revealed that class composition in terms of PSP was differentially associated with students´ psychosomatic complaints, depending on their individual PSP. Findings highlight the vulnerability of students with poor PSP placed in classes with a higher percentage of students with good PSP. Results of this study therefore indicate a need for initiatives for low performing students from teachers and school staff in class. KW - School performance KW - Reference group effects KW - Health complaints KW - BFLPE KW - Multilevel analysis KW - HBSC Y1 - 2018 U6 - https://doi.org/10.1186/s12889-018-5977-5 SN - 1471-2458 VL - 18 ER -