Vibrational properties of the H-N-H complex in dilute III-N-V alloys: Infrared spectroscopy and density functional theory

The nitrogen and hydrogen vibrational modes of hydrogenated GaAs1-yNy and GaP1-yNy have been studied by infrared absorption spectroscopy and density functional theory. Data for the stretching modes observed for samples containing both hydrogen and deuterium show that the dominant defect complex contains two weakly coupled N-H stretching modes. Theory predicts an H-N-H complex with C-1h symmetry whose vibrational properties are in excellent agreement with experiment. Additional results provide further support for the defect model that has been proposed. Uniaxial stress results confirm that the symmetry of the H-N-H complex must be lower than trigonal. The vibrational properties predicted by theory for the H-N-H complex also lead to an assignment of the wagging modes that are observed. Experimental and theoretical results for GaAs1-yNy and GaP1-yNy are remarkably similar, showing that the same H-N-H defect complex is responsible for the properties of H in these fascinating materials.