Photoanodic Dissolution Reaction of an n‐Type Gallium Phosphide Electrode and Its Effect on Energies of the Electronic Bands at the Surface

Abstract

Mott-Schottky plots obtained at dark and under weak illumination have shown that the energies of the electronic bands at the surface of an n-GaP electrode are sifted downward, toward more negative, by illumination under anodic polarization. The magnitude of the shift for the (lll)-face of the electrode was somewhat smaller than that for the (lll)-face. The results are explained by taking account of photoanodically formed surface intermediates, causing a change in the potential difference at the semiconductor-solution interface. These intermediates were found to decay in several minutes at dark under anodic polarization. It is suggested that these intermediates also act as effective surface recombination centers. 9 Electrochemical Society Active Member.