The influence of photoexcitation level on the process of charge transfer in polycrystalline PbS films

Abstract

In this article we discuss the following peculiarities in the photoconductivity of polycrystalline PbS films: the existence of a maximum at certain T in the temperature dependence of photoconductivity; the fact that the lifetime of non-equilibrium carriers at high T depends on T according to the activation law, whereas at low T it does not depend on T; the decrease in lifetime with the growth of light intensity according to the law τ∝ I −1. The problems are discussed on the basis of the percolation theory of charge transfer in disordered materials.