The effect of ion-beam produced lattice defects, as well as implanted ions (H, B, C, N, O, Si), upon the luminescence of the wurtzite phase was studied by means of cathodoluminescence spectroscopy. The results indicated that intrinsic lattice defects, produced by ion bombardment, acted mainly as non-radiative recombination centers and did not give rise to yellow luminescence. Experimental data clearly showed that C was involved in the defect-impurity complex which was responsible for yellow luminescence. The C-related complexes also appeared to act as efficient non-radiative recombination centers. Implantation with H produced a broad luminescent peak which was slightly blue-shifted, with respect to the C-related yellow luminescence band, in the case of high excitation densities. The position of this H-related yellow luminescence peak exhibited a blue-shift with increasing excitation density.

Chemical Origin of the Yellow Luminescence in GaN. S.O.Kucheyev, M.Toth, M.R.Phillips, J.S.Williams, C.Jagadish, G.Li: Journal of Applied Physics, 2002, 91[9], 5867-74