Comment on "Energetics of DX-center formation in GaAs and AlxGa1-xAs alloys"

Abstract

The prediction of Chadi and Chang [Phys. Rev. B 39, 10 063 (1989)] that the DX center in GaAs is a negatively charged defect is investigated. It is found from ab initio self-consistent pseudopotential calculations that the proposed negatively charged center is a metastable state and not a ground state at hydrostatic pressures up to 60 kbar.