Photoconductivity Speed of Response for High Intensity Excitation in Cadmium Sulfide and Selenide

Abstract

The rise and decay time of photoconductivity in single crystals, sintered layers, and evaporated layers of cadmium sulfide and cadmium selenide with a wide range of sensitivities, has been measured for excitation at room temperature by a 1900°K incandescent source giving 1740 ft‐c illumination on the sample. The data thus obtained are useful for determining the dependence of the speed of response on the sample's photosensitivity and for estimating a practical upper limit to the speed of response of these photoconductors. The minimum response times found for the samples tested were rise time of 250 μsec and decay time of 300 μsec for cadmium sulfide and rise time of 17 μsec and decay time of 8 μsec for cadmium selenide.