Dresden 2020 – wissenschaftliches Programm
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CPP 52.2: Vortrag
Dienstag, 17. März 2020, 14:15–14:30, POT 151
InP(100) surfaces for efficient photoelectrochemical water splitting — •Olfa Dani1, Mario Kurniawan2, Agnieszka Paszuk1, Manali Nandy1, Andreas Bund2, and Thomas Hannappel1 — 1Institute of Physics, Technische Universitaet Ilmenau, Germany — 2Institute of Materials Science and Engineering, Technische Universitaet Ilmenau, Germany
To date, III-V semiconductor device structures enable the highest solar-to-hydrogen efficiencies. In this approach, a detailed understanding of the reactions at the semiconductor-electrolyte interface is essential to design the semiconductor surface for efficient charge transfer . In this work, we studied the atomic structure of InP(100)-based photocathode surfaces before and after exposure to an aqueous electrolyte. The preparation of P- or In-rich surfaces on p-type InP(100) wafers with metal organic vapor phase epitaxy (MOVPE) was monitored in situ with reflection anisotropy spectroscopy (RAS). After contamination-free transfer from an MOVPE reactor to ultra-high vacuum, the surface structures were characterized by photoelectron spectroscopy (PES) and low-energy electron diffraction (LEED). Subsequently, the samples were transferred under nitrogen gas to a sealed photoelectrochemical cell for photocurrent density-potential measurements. In order to resolve changes in the surface chemistry and structure after exposure to the electrolyte, the samples were analyzed again by RAS, PES and LEED. For comparison, the same measurements were performed on InP(100) wafers with a native oxide layer.  M. M. May et al., J. Phys. Chem. C 118 (2014) 19032.