The effect of fields due to charge centers at random locations in a semiconductor crystal on the electronic structure of neutral acceptors and on the polarization of luminescence generated by 〈conduction band〉-acceptor transitions

Abstract

Random fields in semiconductor crystals created by charged impurities and other defects give rise to an additional splitting of acceptor levels, which by virtue of the random direction of these fields leads to a decrease in the degree of polarization of luminescence from the semiconductor when the latter is under uniaxial strain. In this paper, the usual description of depolarization of the luminescence based on the effective-temperature mechanism is generalized to include the influence of the Coulomb field of randomly located charge centers on the ground state of an acceptor in an external uniaxial strain field. It is possible to estimate the concentration of charge centers by comparing the polarization characteristics of luminescence calculated within this model from a semiconductor under pressure along the [100] axis with experimental data at low temperatures.