The structure, reorientation and passivation of complexes that formed from a H atom and As-site or Ga-site acceptors (SiAs-H-Ga, ZnGa-H-As) were investigated by using first-principles local density functional methods. In both complexes, the stable configuration corresponded to the situation where the H atom was located at a bond-centered site. The H atom was bound to the Si acceptor in the SiAs-H-Ga complex, and to the As atom in the ZnGa-H-As complex. Similar vibrational properties and reorientation kinetics were found theoretically for both complexes, in spite of the differing H bonds. The present calculations reproduced well the experimental values of the vibrational frequencies and complex dissociation energies, as well as accounting for acceptor passivation. Good agreement was also found with the reorientation energy of the SiAs-H-Ga complex, whereas the unusually high relaxation rates of the ZnGa-H-As complex, as measured during anelastic relaxation investigations, remained unexplained.

A.A.Bonapasta, M.Capizzi, P.Giannozzi: Physical Review B, 1998, 57[20], 12923-31