Antisite defects in III-V semiconductors

A simple, semiempirical model, based upon chemical trends of experimentally determined ground-state energies of sp3-bonded impurities, is used to calculate energy levels of antisite defects in several III-V compounds. This model includes the effects of different charge states, and our calculations are performed for the neutral, singly ionized, and doubly ionized antisite defects on both anion and cation sites. Our results for AsGa and PGa show good agreement with recent measurements and calculations, and therefore support the experimental identification of these defects. In contradiction to almost all previous calculations, we predict deep (T2) levels for the cation antisite defects in GaP and GaAs within the main energy gap.