Calculation of interface and space charge layer quantities of semiconductor electrodes

Abstract

Macroscopic charge balance expressions for chemisorption processes connected with partial charge transfer are applied to calculations of interfacial and space charge layer quantities of semiconductor electrodes. The following topics are discussed: (1) low-coverage adsorption isotherm in dependence of the Helmholtz potential drop π H and the spacecharge layer potential drop π sc; (2) dπ sc/dπ H, including a simple chemisorption process for the non-degenerate depletion and accumulation layer; (3) ratio of total π sc to π H at equilibrated chemisorption; (4) total semiconductor electrode capacity curves. Moreover, non-stationary entropy balance expressions for surface and space-charge layer processes of a semiconductor electrode are presented, and m coefficients for an electrochemical two-step reaction derived.