Substrate temperature dependence of the photoluminescence efficiency of co-sputtered Si/SiO2 layers

Si particles embedded in an SiO2 matrix were obtained by co-sputtering of S i and SiO2 at various deposition temperatures T-d (200-700 degrees C) and a nnealing at different temperatures T-a (900-1100 degrees C). The systems we re characterized by X-ray photoelectron, Raman scattering, infrared absorpt ion and photoluminescence spectroscopy techniques. The results show that th e photoluminescence efficiency is strongly dependent on the degree of phase separation between the Si nanocrystals and the SiO2 matrix. This is likely connected with the Si/SiO2 interface characteristics, together with the fe atures indicating the involvement of quantum confinement. (C) 1999 Elsevier Science B.V. All rights reserved.