The effect of ultra-violet irradiation upon the annealing of as-grown Mg-doped films was studied by means of resistometric and Hall-effect measurements. It was found that the annealing temperature, at which a resistivity reduction due to the electrical activation of H-passivated Mg occurred, with an increase in the hole density and a decrease in hole mobility, was reduced from 550 to 450C by irradiation with ultra-violet light having a peak wavelength of around 350nm. It was suggested that electronic excitation reduced the thermal stability of Mg-H complexes.

Photo-Enhanced Activation of Hydrogen-Passivated Magnesium in p-Type GaN Films. Y.Kamiura, Y.Yamashita, S.Nakamura: Japanese Journal of Applied Physics - 2, 1998, 37[8B], L970-1