Photodecomposition of semiconductors thermodynamics, kinetics and application to solar cells

Abstract

Photodecomposition of semiconductors is caused by reactions of electrons of holes at the surface. Thermodynamic criteria for such processes are derived. The thermodynamics and kinetics depend on the energy position of the band edges and the concentration of electrons and holes at the surface which can both vary under illumination. The role of competing redox reactions and the influence of surface states on the decomposition reactions are discussed. Consequences for photoelectrochemical solar cells are outlined.