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 - GEN A1 - Richter, Matthias R. A1 - Cheng, Wen-Hui A1 - Crumlin, Ethan J. A1 - Drisdell, Walter S. A1 - Atwater, Harry A. A1 - Schmeißer, Dieter A1 - Lewis, Nathan S. A1 - Brunschwig, Bruce S. T1 - X‑ray Photoelectron Spectroscopy and Resonant X‑ray Spectroscopy Investigations of Interactions between Thin Metal Catalyst Films and Amorphous Titanium Dioxide Photoelectrode Protection Layers T2 - Chemistry of Materials N2 - The use of electrochemistry, X-ray photoelectron spectroscopy, and resonant X-ray spectroscopy has unlocked the paradox of interfacial hole conduction through amorphous TiO2 (a-TiO2) to deposited Ni, Ir, and Au metal catalysts. Although electrocatalysts for the oxygen-evolution reaction derived from metallic Ir and Ni have mutually similar overpotentials in alkaline media, Si/a-TiO2/Ir interfaces exhibit higher overpotentials than Si/a-TiO2/Ni interfaces. The data allow formulation of full band energy diagrams for n-Si/a-TiO2/metal interfaces for M = Ni, Ir, or Au. Although both Ni and Ir produce band bending in a-TiO2 favoring hole conduction, only Ni creates multiple states within the a-TiO2 band gap at the a-TiO2/Ni interface, which produces a quasi-metallic interface at the a-TiO2/Ni junction. Au, however, produces a flat-band interface that limits hole conduction without any new band gap states. KW - X‑ray Photoelectron Spectroscopy KW - Resonant X‑ray Spectroscopy KW - titanium oxide KW - oxygen-evolution reaction KW - protection layer KW - interface interaction Y1 - 2021 U6 - https://doi.org/10.1021/acs.chemmater.0c04043 SN - 0897-4756 SN - 1520-5002 VL - 33 IS - 4 SP - 1265 EP - 1275 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 - JOUR A1 - Schmeißer, Dieter A1 - Richter, H. A1 - Pfitzner, L. A1 - Prasad, S. T1 - E-MRS 1999 Spring Meeting, Strasbourg, June1-4,1999-Preface Y1 - 2000 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 - CHAP A1 - Peplowsky, Stefan A1 - Richter, Christian A1 - Jacobitz, S. A1 - Woll, Ralf ED - Dahlgaard-Park, Su Mi ED - Dahlgaard, Jens Jörn T1 - Individuality - A challenge for production and quality T2 - Proceedings, 19th QMOD-ICQSS Conference International Conference on Quality and Service Sciences, Rom (Italy) Y1 - 2016 SN - 978-91-7623-086-2 SP - 1538 EP - 1546 PB - Lund CY - Lund University Library Press ER - TY - GEN A1 - Spitzer, Stefan G. A1 - Richter, P. A1 - Knaut, M. A1 - Schüler, S. T1 - Treatment of Atrial Fibrillation in Open Heart Surgery. The Potential Role of Microwave Energy T2 - The Thoracic and Cardiovascular Surgeon Y1 - 1999 SN - 0946-4778 VL - 47 IS - Supplement 3 SP - 374 EP - 378 ER - TY - GEN A1 - Knaut, M. A1 - Spitzer, Stefan G. A1 - Karolyi, L. A1 - Ebert, H.-H. A1 - Richter, P. A1 - Tugtekin, Sems M. A1 - Schuler, S. T1 - Intraoperative Microwave Ablation for Curative Treatment of Atrial Fibrillation in Open Heart Surgery - The MICRO-STAF and MICRO-PASS Pilot Trial T2 - The thoracic and cardiovascular surgeon N2 - Concomitant microwave ablation for curative treatment of atrial fibrillation (AF) was performed in 18 patients with history of chronic atrial fibrillation and indication for open heart surgery, 11 patients with mitral valve replacement and 7 patients with coronary artery bypass grafting. There were no perioperative complications. During the postoperative period most of the patients had intermittent AF, they received low dose Sotalol therapy and electric cardio-versions. Up to now seven patients have reached follow-up day 90. One patient has persistent AF. Two patients had typical atrial flutter that was electrically converted to sinus rhythm (SR), isthmus ablation is planned. The other four patients have SR, one patient without cardioversions. These four patients show recovered atrial function with observed A-wave for transmitral flow. Under visual guidance the continuous atrial lesion lines could be induced effectively and safely by the intraoperative device Lynx. KW - Atrial fibrillation KW - Intraoperative microwave ablation Y1 - 1999 UR - https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-2007-1013205 U6 - https://doi.org/10.1055/s-2007-1013205 SN - 1439-1902 SN - 0171-6425 VL - 47 IS - Suppl. 3 SP - 379 EP - 384 ER - TY - GEN A1 - Piriz, S. A. A1 - Piriz, Antonio R. A1 - Tahir, Naeem A. A1 - Richter, Sebastian A1 - Bestehorn, Michael T1 - Rayleigh-Taylor instability in elastic-plastic solid slabs bounded by a rigid wall T2 - Physical Review E N2 - The linear evolution of the incompressible Rayleigh-Taylor instability for the interface between an elastic-plastic slab medium and a lighter semi-infinite ideal fluid beneath the slab is developed for the case in which slab is attached to a rigid wall at the top surface. The theory yields the maps for the stability in the space determined by the initial perturbation amplitude and wavelength, as well as for the transition boundary from the elastic to the plastic regimes for arbitrary thicknesses of the slab and density contrasts between the media. In particular, an approximate but very accurate scaling law is found for the minimum initial perturbation amplitude required for instability and for the corresponding perturbation wavelength at which it occurs. These results allows for an interpretation of the recent experiments by Maimouni et al. [Phys. Rev. Lett. 116, 154502 (2016)]. KW - Rayleigh-Taylor instability KW - Research Areas Flow instability KW - Research Areas Nonlinear phenomena in plasmas KW - Plasma instabilities Plasma macroinstabilities Y1 - 2021 UR - https://journals.aps.org/pre/abstract/10.1103/PhysRevE.103.023105 U6 - https://doi.org/10.1103/PhysRevE.103.023105 SN - 2470-0045 VL - 103 IS - 2 SP - 023105-1 EP - 023105-12 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 -