Various samples were exposed to electron and  radiation, at 300 and 77K respectively. The effect of exposure to high-energy radiation was investigated by using photoluminescence techniques. A large reduction in the photoluminescence signals was observed, due to the defects which were introduced. In the case of -irradiated samples, the photoluminescence characteristics recovered after room-temperature aging. In the case of electron-irradiated samples, heat treatment at 473 or 673K was required in order to anneal out the radiation-induced defects. The differing roles which were played by the amphoteric dopant, Sn, and the n-type dopant, S, in altering the photoluminescence near to band-edge spectra were considered.

P.L.Souza, P.R.Ribas, J.V.Bellini, W.M.Mendes: Journal of Applied Physics, 1996, 79[7], 3482-6