The complexes which were formed by atomic H and Ga vacancies, which were thought to account for donor-acceptor bands in the photoluminescence spectra of hydrogenated samples, were considered. New configurations for these complexes were investigated here, together with the kinetic properties of the H donors that critically affected complex-stability. In addition to the H donor, a peculiar VGa-H complex was shown to act as a donor. Electronic levels in the energy gap, and several H vibrational modes, were studied for new and old configurations of the VGa-H complexes; as well as for the new donor. The new complexes were more stable than those previously studied and could account well for the photoluminescence results. The values of the H vibrational frequencies were quite different for the various types of complex, and this was expected to permit the determination of the microstructure of the VGa-H complexes by means of infra-red spectroscopy.

Structure, Kinetics, and Vibrational Properties of Complexes Formed by Hydrogen and Gallium Vacancies in GaAs - a Theoretical Study A.Amore Bonapasta, M.Capizzi: Physical Review B, 2000, 61[12], 8180-6