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O: Fachverband Oberflächenphysik
O 46: Poster Session IV: Semiconductor substrates II
O 46.3: Poster
Tuesday, March 2, 2021, 13:30–15:30, P
GaInP(100) and InP(100) with different surface reconstructions for photoelectrochemical water splitting — •Olfa Dani1, David Ostheimer1, Mario Kurniawan2, Agnieszka Paszuk1, 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, exceeding 19%. 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 present work, we study photoelectrochemical (PEC) performance of atomically well-ordered surfaces of GaInP(100)and InP(100) grown by MOVPE. p-type InP have been grown homoepitaxially on InP(100) substrates. GaInP buffer layers were grown lattice matched, on either GaAs or Ge (100) substrates. In order to avoid anti-phase boundaries in the III-V epilayers, the Ge(100) surface was prepared with double-atomic steps prior to growth. The surfaces involved were prepared with either P-rich (2x1) or III-rich (2x4) surface reconstructions via specific preparation routes controlled by optical in situ spectroscopy and identified in UHV by LEED. Selected samples were in system transferred in an inert nitrogen ambiance to a PEC cell, where they were exposed to an aqueous electrolyte. For comparison, the same measurements were performed on samples with a native oxide layer. We show that a precise surface preparation is crucial for efficient PEC processes.