On Anomalously High Photosensitivity of CdS1 –xSex Granular Films

Abstract

An anomalously high photosensitivity of \({\text{Cd}}{{{\text{S}}}_{{{\text{1--}}x}}}{\text{S}}{{{\text{e}}}_{x}}\) granular films observed in the experiment is explained. It is assumed that the charge transfer mechanism based on surface states existing at the granule boundaries can be responsible for an anomalously high photocurrent-to-dark current ratio recently found in the study of the photoconductivity of \({\text{Cd}}{{{\text{S}}}_{{{\text{1--}}x}}}{\text{S}}{{{\text{e}}}_{x}}\) granular films. It has been shown that the current of charge carriers in surface states flowing through the gaps between the granules at a certain film topology can exceed by many orders of magnitude the current associated with tunneling of charge carriers between the granules.