AsGaantisite defect in GaAs

Abstract

Calculations of the electronic states associated with the ${\mathrm{As}}_{\mathrm{Ga}}$ antisite defect in GaAs are carried out with the use of the self-consistent Green's-function technique. The defect is found to produce two deep donor levels separated by a $U\approx 0.27$ eV. The absolute positions of the levels are somewhat uncertain (∼0.2 eV) since they are affected by corrections necessary to improve on the GaAs gap values calculated by the local-density-functional method. The overall picture, however, supports a recent experimental assignment of the ${\mathrm{As}}_{\mathrm{Ga}}$ defect by Weber et al.