Local-environment effects on localised states in III-V alloys

Abstract

A theoretical approach is developed for the local-environment effects on the electronic spectra of an impurity in weakly disordered alloys (WDA). It is obtained from an embedded-cluster technique using suitable approximations for the WDA. This approach is illustrated using a simple density of states shape for the host alloy and a description of the impurity centre using one state per atom. The simplicity of the formalism involved in this approach makes it a good candidate for applications to real alloys, as shown by the application to the determination of nitrogen-bound electron levels in Ga_1-xIn_xP:N.