Experimental evidence was presented for the electron-beam induced diffusion of O and H in unintentionally doped n-type material which had been grown on a sapphire substrate. Impurity diffusion was investigated by using cathodoluminescence techniques at 4 and 300K and by using wavelength-dispersive X-ray analysis. The results illustrated the significance of electron-beam induced electromigration in wide-bandgap semiconductors, confirmed the role played by ON• in bound excitons, donor-acceptor pairs and yellow emissions, and suggested the involvement of ON• and hydrogenated Ga vacancies in blue luminescence.

Direct Experimental Evidence for the Role of Oxygen in the Luminescent Properties of GaN. M.Toth, K.Fleischer, M.R.Phillips: Physical Review B, 1999, 59[3], 1575-8