Films of Si-rich oxide, with a thickness of about 1.2μ, were deposited onto p-type Si substrates by means of radio-frequency magnetron sputtering. After annealing at various temperatures in a N2 atmosphere, the photoluminescence spectra of all of the samples exhibited 2 main peaks; at about 710 and 800nm. After γ-irradiation, these 2 photoluminescence peaks increased in intensity by 3 to 5 times. A strong new 580nm peak also appeared. The positions of all 3 photoluminescence peaks underwent no evident shift when the measurement temperature was increased from 10 to 300K. The results were explained in terms of a model which assumed that photo-emission occurred due to luminescence centers, rather than nm-sized Si particles, in the Si-rich oxide films.

S.Y.Ma, B.R.Zhang, G.G.Qin, Z.C.Ma, W.H.Zong, X.T.Meng: Materials Research Bulletin, 1997, 32[10], 1427-33