Degradation of S-treated surfaces at relatively low temperatures was investigated by means of X-ray photo-electron and photoluminescence spectroscopy. The results showed that the treated surfaces were oxidized to In2O3, InPO3, and InPO4 at 250C (10-3Torr, 0.33h). As the holding time under a vacuum of 10-3Torr was increased, the photoluminescence peak that was caused by the band edge transition decreased; without the formation of oxides. It was suggested that the decrease in the photoluminescence intensity of S-treated material was related only to the generation of P vacancies at the surface, and not to oxide formation.

I.K.Han, E.K.Kim, J.I.Lee, S.H.Kim K.N.Kang, Y.Kim, H.Lim, H.L.Park: Journal of Applied Physics, 1997, 81[10], 6986-91