Native defects were studied by performing first-principles total energy calculations. The structures and formation energies of the stable defects were reported, and the defect concentrations under various growth conditions were estimated. The most important native defect was the GaSb antisite, which acted as an acceptor. The other important defects were the acceptor-type Ga vacancy and the donor-type Ga interstitial. The Sb vacancies and interstitials were found to have much higher formation energies. A metastable state was observed for the SbGa antisite. The significantly larger concentrations of Ga vacancies and interstitials, as compared with the corresponding Sb defects, was in accord with its asymmetrical self-diffusion behavior in GaSb. The data supported the next-nearest neighbor model for self-diffusion; in which migration occurred independently in the various sub-lattices. Self-diffusion was dominated by moving Ga atoms.

Native Defects and Self-Diffusion in GaSb. M.Hakala, M.J.Puska, R.M.Nieminen: Journal of Applied Physics, 2002, 91[8], 4988-94