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

摘要

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_2SO_4. The variation of saturated photocurrent of 1 to 3 cycles in H_2SO_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.