Surface Stabilities of n-type GaN Dependent on Electrolyte under Photoelectrochemical Reactions

Abstract

The n-type GaN has stability problem of the surface anodic corrosion during the photoelectrochemical reaction for H 2 generation. The photoelectrochemical surface stabilities of n-type GaN dependent on the electrolytes were investigated. The flatband potential in HCl obtained from Mott-Schottky plot shifted 0.1 V to positive direction compared with that in H 2 SO 4 . The variation of saturated photocurrent of 1 to 3 cycles in H 2 SO 4 was much larger than that of HCl, NaOH and KOH. The surface morphologies also changed by the electrolytes. These results show the absorbed materials on the GaN electrode surface during the photoelectrochemical reactions were changed by the electrolyte and affected the surface reactions.