Derivation of charge transfer parameters at semiconductor-liquid interfaces

Abstract

The excess-carrier charge transfer velocity, υ_cp, is an important parameter describing the efficiency of charge transfer across a solid-liquid interface. By using recent theory to analyze current-voltage curves of photoelectrochemical cells, we have been able to derive values of υ_cp for CdSe films in aqueous polysulfide electrolytes and measure the effects of varying the sulfur concentration. The parameter, υ_cp, is found to vary at short circuit conditions, from 1.2 × 10⁶ to 1.36 × 10⁶ cm s⁻¹ on increasing the sulfur concentration from 0 to 3.0M. In addition it has been found that υ_vp has only a weak voltage dependence described by an equation linear in voltage.