A Model for DX Centers: Bond Reconstruction due to Local Random Donor-Host Atom Configurations in Mixed Semiconductor Alloys

Abstract

A bond reconstruction model for DX centers is proposed. The model assumes the inherent instability in the sp 3 covalent bonding between donor and host atoms in the indirect gap regime. This instability is due to the localization of donor bound electrons. The instability results in bond reconstruction which is governed by local host atom configurations around the donor atoms. The DX centers are resultant self-generated donor vacancy pairs.