Hot carrier injection of photogenerated electrons at indium phosphide–electrolyte interfaces

Hot electron reduction of p-nitrobenzonitrile at (111) p-InP in acetonitrile electrolyte was observed as a supraband-edge redox reaction. The band-edge positions of the p-InP electrode were unequivocally established from Mott–Schottky data obtained as a function of light intensity and frequency. Special conditions of low light intensity and electrode potential were found wherein the semiconductor band edges were either fixed or had moved only very slightly with respect to redox potentials in the electrolyte, such that the respective supraband-edge redox reactions were definitely outside the band gap of InP.