It was recalled that, in n-type material, the diffusion of atoms which resided on the Ga sub-lattice occurred mainly via Ga vacancies. In order to elucidate the microscopic details and energetics of these processes, local density approximation estimates were made of the total energies, electronic structures, and relaxed positions of atoms in microscopic configurations which were relevant to the diffusion of Si donors. It was found that a DX-like mechanism facilitated the migration of lattice site atoms into the interstitial region. A bond-passing mechanism was also identified, in which a second-nearest neighbour vacancy assisted migration through the interstitial region. Due to these 2 mechanisms, vacancy-assisted Si diffusion in n-type material was characterized by an energy barrier of about 1.0eV.

J.Dabrowski, J.Northrup: Materials Science Forum, 1994, 143-147, 1263-8