TY - JOUR A1 - Wichter, Lutz A1 - Richter, F. T1 - Beständigkeit von Pflastersteinen aus haufwerksporigem Beton bei Beanspruchung durch Frost und Tausalz Y1 - 2001 ER - TY - GEN A1 - Rudolph, Matthias A1 - Achouche, M. A1 - Kraus, S. A1 - Spitzbart, Th. A1 - Kurpas, Paul A1 - Rentner, D. A1 - Brunner, F. A1 - Richter, E. A1 - Bergunde, T. A1 - Heymann, Peter A1 - Wolter, P. A1 - Wittrich, H. A1 - Weyers, M. A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - InGaP/GaAs Power HBTs for L-Band Applications Y1 - 1999 ER - TY - GEN A1 - Sonia, G. A1 - Richter, E. A1 - Brunner, F. A1 - Denker, A. A1 - Lossy, R. A1 - Mai, M. A1 - Lenk, Friedrich A1 - Bundesmann, J. A1 - Pensl, G. A1 - Schmidt, J. A1 - Zeimer, U. A1 - Wang, L. A1 - Baskar, K. A1 - Weyers, M. A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - 2 MeV ion irradiation effects on AlGaN/GaN HFET devices T2 - Solid-State Electronics N2 - AlGaN/GaN heterostructure field effect transistors (HFETs) were irradiated with 2 MeV protons, carbon, oxygen, iron and krypton ions with fluences ranging from 1 × 109 cm−2 to 1 × 1013 cm−2. DC, pulsed I–V characteristics, loadpull and S-parameters of the AlGaN HFET devices were measured before and after irradiation. In parallel, a thick GaN reference layer was also irradiated with the same ions and was characterized by X-ray diffraction, photoluminescence, Hall measurements before and after irradiation. Small changes in the device performance were observed after irradiation with carbon and oxygen at a fluence of 5 × 1010 cm−2. Remarkable changes in device characteristics were seen at a fluence of 1 × 1012 cm−2 for carbon, oxygen, iron and krypton irradiation. Similarly, remarkable changes were also observed in the GaN layer for irradiations with fluence of 1 × 1012 cm−2. The results found on devices and on the GaN layer were compared and correlated. Y1 - 2008 UR - http://www.sciencedirect.com/science/article/pii/S0038110108000671 SN - 0038-1101 VL - 52 IS - 7 SP - 1011 EP - 1017 ER - TY - GEN A1 - Gnanapragasam, S. A1 - Richter, E. A1 - Brunner, F. A1 - Denker, A. A1 - Lossy, R. A1 - Mai, M. A1 - Lenk, Friedrich A1 - Opitz-Coutureau, J. A1 - Pensl, G. A1 - Schmidt, J. A1 - Zeimer, U. A1 - Wang, L. A1 - Krishnan, B. A1 - Weyers, M. A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - Irradiation effects on AlGaN HFET devices and GaN layers T2 - Journal of Materials Science: Materials in Electronics N2 - AlGaN/GaN heterostructure field effect transistors (HFETs) were irradiated with protons as well as carbon, oxygen, iron and krypton ions of high (68 and 120 MeV) and low (2 MeV) energy with fluences in the range from 1x107 to 1x1013 cm-2. High energy irradiation with protons, carbon and oxygen produced no degradation in devices while krypton irradiation at the fluence of 1x1010 cm-2 resulted in a small reduction of 2% in the transconductance. Similarly, for GaN samples irradiated with protons, carbon and oxygen at high energy no changes were seen by XRD, PL and Hall effect, while changes in lattice constant and a reduction in PL intensity were observed after irradiation with high energy krypton. Low energy irradiation with carbon and oxygen at a fluence of 5x1010 cm-2 results in small change in the device performance while remarkable changes in device characteristics are seen at a fluence of 1x1012 cm-2 for carbon, oxygen, iron and krypton irradiation. Similarly changes are also observed by XRD, PL and Hall effect for the thick GaN layer irradiated at the fluence of 1x1012 cm-2. The device results and GaN layer properties are strongly correlated. Y1 - 2008 U6 - https://doi.org/10.1007/s10854-008-9589-1 SN - 1573-482X VL - 19 IS - 1 SP - 64 EP - 67 ER - TY - GEN A1 - Sonia, G. A1 - Richter, E. A1 - Brunner, F. A1 - Denker, A. A1 - Lossy, R. A1 - Lenk, Friedrich A1 - Opitz-Coutureau, J. A1 - Mai, M. A1 - Schmidt, J. A1 - Zeimer, U. A1 - Wang, L. A1 - Baskar, K. A1 - Weyers, M. A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - High energy irradiation effects on AlGaN/GaN HFET devices T2 - Semiconductor Science and Technology N2 - The effect of proton, carbon, oxygen and krypton irradiation on AlGaN HFET devices has been studied. Irradiation was performed at 68 and 120 MeV with fluences in the range from 1 × 10^7 to 1 × 10^13 cm2 . Before and after irradiation, dc and pulsed I – V characteristics, loadpull and S -parameters of the AlGaN HFET devices were measured. A thick GaN reference layer was characterized by x-ray diffraction, photoluminescence and Hall measurements before and after irradiation. Proton, carbon and oxygen irradiation show no degradation in devices while krypton irradiation shows a small change at a fluence of 1 × 10 10 cm2 in the device characteristics. The device results are correlated with the thick GaN results. Y1 - 2007 U6 - https://doi.org/10.1088/0268-1242/22/11/007 SN - 0268-1242 VL - 22 IS - 11 SP - 1220 EP - 1224 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 - 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 - RPRT A1 - Müller, Jörg A1 - Dieter, M. A1 - Bauhus, J. A1 - Spellmann, H. A1 - Möhring, B. A1 - Wagner, S. A1 - Wolf, Heino A1 - Niekisch, M. A1 - Weiger, H. A1 - Feindt, Peter H. A1 - Hamm, Ulrich A1 - Wätzold, Frank A1 - Wolters, Volkmar A1 - Engels, Eve-Marie A1 - Schraml, U. A1 - Lang, F. A1 - Pröbstl-Haider, U. A1 - Richter, K. T1 - Wege zu einem effizienten Waldnaturschutz in Deutschland. Stellungnahme Y1 - 2020 UR - http://www.fnr.de/fileadmin/allgemein/pdf/Effizienter_Waldnaturschutz_in_Deutschland.pdf PB - Wissenschaftlicher Beirat Waldpolitik und Wissenschaftlicher Beirat Biodiversität und Genetische Ressourcen beim BMEL ER - TY - GEN A1 - Harlander, U. A1 - Schön, F.-T. A1 - Borcia, I. D. A1 - Richter, S. A1 - Borcia, R. A1 - Bestehorn, M. T1 - Resonant water-waves in ducts with different geometries: forced KdV solutions T2 - European Journal of Mechanics - B/Fluids Y1 - 2024 U6 - https://doi.org/10.1016/j.euromechflu.2024.03.008 SN - 0997-7546 VL - 106 IS - July–August 2024 SP - 107 EP - 115 ER - TY - GEN A1 - Borcia, I. D. A1 - Bestehorn, M. A1 - Borcia, R. A1 - Schön, F.-T. A1 - Harlander, U. A1 - Richter, S. T1 - Mean flow generated by asymmetric periodic excitation in an annular channel T2 - The European Physical Journal Special Topics Y1 - 2024 U6 - https://doi.org/10.1140/epjs/s11734-024-01181-8 VL - 233 (2024) SP - 1665 EP - 1672 PB - Springer ER - TY - GEN A1 - Schön, F.-T. A1 - Borcia, I. D. A1 - Harlander, U. A1 - Borcia, R. A1 - Richter, S. A1 - Bestehorn, M. T1 - Resonant surface waves in an oscillating periodic tank with a submerged hill T2 - Journal of Fluid Mechanics Y1 - 2024 U6 - https://doi.org/10.1017/jfm.2024.885 VL - 999 (2024) SP - 1 EP - 18 ER -