SEMICONDUCTOR ELECTRODES .17. ELECTROCHEMICAL BEHAVIOR OF N-TYPE AND P-TYPE INP ELECTRODES IN ACETONITRILE SOLUTIONS

The photoelectrochemical behavior of n- and p-InP single crystal semiconductors was investigated in acetonitrile (ACN) solutions which contained various electroactive compounds. The cyclic voltammograms of the semiconductors in the dark and illuminated with red light were compared to the Nernstian behavior at a Pt disk electrode. The extent of photodissolution of the semiconductors was decreased in ACN compared to aqueous solutions at similar potentials. Intermediate levels or surface states located between the conduction band and valence band which mediate electron transfer with solution redox couples are proposed. An underpotential was developed for the photo assisted oxidations and reductions with n- and p-InP, respectively, and the potential range for photoreductions on p-InP extended negative of the conduction bandedge. The electrochemical behavior and magnitude of the under-potentials is compared to results with InP in aqueous solutions and with other semiconductors in ACN. © 1979, The Electrochemical Society, Inc. All rights reserved.