Both luminescence properties and dissociation kinetics of Mg–H complex for as-grown Mg-doped GaN were simultaneously investigated by means of low-energy electron-excited nanoluminescence spectroscopy. Ultraviolet luminescence at 3.2 to 3.3eV and blue luminescence at 2.8 to 2.9eV were observed as predominant low-energy electron-excited nanoluminescence emissions. In-depth profiles of low-energy electron-excited nanoluminescence emission showed that the blue luminescence was the predominant emission for highly Mg-doped GaN. Electron-beam exposures of less than 50mC/cm2 produced an increase in the ultra-violet luminescence intensity and reduced the blue luminescence intensity. These characteristics suggested that the blue luminescence was due to a transition from H-related deep donor to Mg acceptor and that the ultra-violet luminescence was due to transitions from conduction band and/or shallow H donor to Mg acceptor. A kinetic model was proposed for dissociation reactions of Mg–H complex during electron exposure, and the reaction rate was deduced to be 3.5 x 10–3/s for electron beams with 3.1 x 10–5A/cm2 at 5.0keV.

Simultaneous Observation of Luminescence and Dissociation Processes of Mg–H Complex for Mg-Doped GaN. Y.Koide, D.E.Walker, B.D.White, L.J.Brillson, M.Murakami, S.Kamiyama, H.Amano, I.Akasaki: Journal of Applied Physics, 2002, 92[7], 3657-61