Optical Transmission and Photoconductive and Photovoltaic Effects in Activated and Unactivated Single Crystals of ZnS

Abstract

Certain physical properties of single crystals of ZnS and of ZnS activated with Mn, Cu, and Al have been determined. The optical studies involve transmission spectra. Photovoltages much larger than the energy gap have been measured. Reversals in the sign of the voltage have been measured as a function of the wavelength of incident light. The photovoltages and photocurrents have been determined as functions of wavelength and of intensity of incident light. A description is presented in which the characteristics of the crystals are treated as simple circuit elements.