The anomalous photovoltaic effect in cadmium telluride

Abstract

The anomalous photovoltaic effect has been investigated in thin films of CdTe deposited by evaporation onto inclined insulating substrates. Electron-microscopic observations show that the films are composed of minute microcrystallites inclined towards the general vapour direction. The anomalous photovoltaic effect has been studied as a function of light intensity, wavelength and angle of incidence, as well as gaseous environment. The results obtained show that existing models are unable fully to explain the effect. Parallel measurements of the surface photovoltages associated with cleaved single-crystal CdTe lead to a new interpretation in terms of surface photovoltages in small inclined crystallites.