THE EFFECTS OF SURFACE ENERGETICS ON THE CYCLIC VOLTAMMETRY OF METALLOCENES AT NONILLUMINATED N-INP ELECTRODES

Electron transfer processes at n-type InP electrodes of moderate to low doping density were investigated by monitoring the cyclic voltammetric dark currents of a series of metallocenes in acetonitrile solutions. The formal reduction potentials of the metallocenes span the bandgap of InP, allowing a comparison of the cyclic voltammetric response as a function of the formal reduction potential and the energetic condition of the electrode surface. The energetic condition of the electrode surface during the cyclic voltammetry experiments was monitored by measurements of the capacitance of the space charge region. A simple chemical etching and electrochemical cycling procedure yielded reproducible surface energetics. The n-InP/acetonitrile interface in the depletion condition responded ideally to changes in electrode potential, as evidenced by linear Mott-Schottky plots, over a range of about 0. 9V.