Hydrogen-related, deeply bound excitons in Mg-doped GaN films

Luminescence in the near band-edge spectral region of Mg-doped GaN films grown by metalorganic chemical vapor deposition has been studied at liquid-helium temperatures. Radiative transitions at 3.37 and 3.416 eV were observed to evolve in cathodoluminescence spectra during electron-beam irradiation at 5 kV. The intensity of the 3.37 eV peak correlates monotonically with the resistivity of the films. By annealing the films in N-2 and N-2/H-2 atmospheres, the 3.37 and 3.416 eV transitions are shown to be related to hydrogen. (C) 2013 AIP Publishing LLC.