Oxygen Chemisorption Effects on Photoconductivity in Sintered Layers

Abstract

Processes involving the adsorption and desorption of oxygen are shown to be of basic importance for the photoconductivity properties of sintered layers of and . Annealing in the light in oxygen decreases photoconductivity and dark conductivity, whereas annealing in the dark in oxygen or in either light or dark in He increases both photoconductivity and dark conductivity. Chemisorbed oxygen decreases the dark conductivity by removing electrons from the conduction band, and decreases the photosensitivity by an effect on the free electron lifetime. The concentration of copper acceptor impurity incorporated in the layer determines the effectiveness of the adsorbed oxygen in establishing a depletion layer, particularly important in the sintered connections between individual particles.