Infrared quenching of photocapacitance in evaporated ZnS : Ag thin films

Abstract

The deep centers in evaporated ZnS : Ag thin films have been characterized by observation of the infrared quenching of photocapacitance using Schottky barriers. The photoionization energy of holes for transitions from Ag centers to the valence band edge is determined to be 0.56 eV at 300 K. The spectral distribution of the photoionization cross section of holes is obtained theoretically. It has been found that the magnitude of the photocapacitance quenching depends linearly on the intensity of the infrared illumination in the low-intensity range. The concentration profile of Ag impurities has been measured and is almost uniform throughout the depletion layer in the films.

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