Quantitative Analysis of Semiconductor Electrode Voltammetry: A Theoretical and Operational Framework for Semiconductor Ultramicroelectrodes

Abstract

A thorough framework for how to interpret and predict the steady-state voltammetric responses of semiconductor ultramicroelectrodes (SUMEs) has been compiled. Through consideration of the Marcus–Gerischer treatment for heterogeneous charge transfer and the interplay between the fractions of the applied potential that drop across the space-charge region, the solution, and their interface in depletion and accumulation conditions, the complex potential dependences of the majority carrier densities, ns, and the rate constant for electron transfer from the conduction band edge, ket, are identified. Incorporation of these terms in the conventional fitting procedures of steady-state voltammetry at inlaid disk electrodes affords determination of the full J–E responses of n-type SUMEs in a variety of experimental permutations. Working curves are presented to illustrate how the specific values of the conduction band edge potential, the reorganization energy for charge transfer, the standard potential of the redox s...