1. First-principles studies of water splitting at semiconductor and oxide surfaces Poul Georg Moses and Chris G. Van de Walle , Materials Department, University of California, Santa Barbara
Electrostatic potential as a function
of distance perpendicular to the surface.
Plus signs mark atomic planes.
A photoelectrochemical cell consists of a semiconductor photoelectrode which absorbs light in the solar spectrum with a valence-band maximum (VBM) and conduction-band minimum (CBM) that straddle the redox potential of water and hydrogen. We have investigated InGaN alloys using first-principles electronic-structure calculations and have determined the band gap and band positions as a function of In content. We find that up to 50% indium content the VBM and CBM indeed straddle the redox potential of water and hydrogen.
Band positions as a function of In content