Photoelectrochemical Properties of Single‐Crystalline n ‐ SiC in Aqueous Electrolytes

Abstract

The photoelectrochemical properties of n-SiC were studied in aqueous electrolytes. The onset potential of the anodic photocurrent in steady state was found to be about 1V more anodic than that of the photocurrent measured by the lock-in method (-2V vs. SCE). This discrepancy was ascribed to the presence of transient photocurrent observed in the potential range between-1.9 and +0.6V vs. SCE. Possible mechanisms of the transient photoresponse were examined. The flatband potential deduced from the Mott-Schottky plot of the C-V characteristics was found to shift into the cathodic direction of potential in the course of the photoelectrochemical measurements. The shift was explained by a hypothesis that thin oxide layer grows on the SiC surface during anodic polarization under strong illumination.