Electron Transfer Involving Tunneling from Surface States at the Dark Anodic CdS/Indifferent Electrolyte Interface

Abstract

AbstractThe anodic dark current at the single crystal CdS/indifferent electrolyte interface was studied on different crystal faces of several samples as a function of applied voltage, of pretreatment of the crystal, of electrolyte composition and of temperature. The results indicate that electron tunneling from surface states located at about 0.12 eV below the conduction band edge into the crystal constitutes the rate‐determining step of the electrode reaction. The observed activation energy of 0.42 eV is interpreted on the basis of an equilibrium between the surface states and the solution. The influence of preliminary etching on the current is attributed to changes in the number of surface states.