Nitrogen–hydrogen complexes in GaAs and GaAs_1–xN_x alloys

Abstract

Abstract We investigate the atomic structure of various N–H complexes in GaAs and GaAs 1– x N x alloys through first‐principles pseudopotential calculations within the local‐density‐functional approximation. For GaAs with low H concentrations, we suggest that nitrogen forms a N–H(BC) complex, where H is positioned at a bond‐center site between a substitutional N and one of the neighboring Ga atoms. For very high H concentrations, an optically inactive N–H 2 * (BC‐AB N ) complex, which corresponds to a configuration of H 2 * in the vicinity of N, is suggested to be an energetically favorable structure. These atomic models explain many experimental features observed in GaAs and GaAs 1– x N x alloys, which contain both N and H.