Photoconductivity of Lead Sulfide Films

Abstract

Extensive experimental data have been taken on thin photoconducting films of lead sulfide of the chemically-oxidized type. Conductivity of the films in the temperature range 77°-300°K depends greatly on the amount of oxidation received by the films. Activation energy approaches a maximum value of 0.35 electron volt, but may have any value down to zero depending on the temperature range, amount of oxidation, and the illumination. Time constants as well as conductivity have been measured at different temperatures and illuminations, and in general tend toward a reciprocal relationship though the detailed behavior is more complicated than a simple reciprocity. Other important properties measured include spectral response and transient response to large changes in illumination.