Department of Electrical and Electronics Engineering, Faculty of Engineering, Kobe University, Rokkodai, Nada, Kobe 657, Japan
Abstract:
Optical properties of Si-rich SiO2 films prepared by an RF cosputtering method are discussed. From the infrared and Raman spectroscopy together with the electron microscopy, it is shown that Si mesoscopic particles embedded in solid matrices with the sizes ranging from ˜ 10 nm (nanocrystals) to less than ˜1 nm (clusters) can be obtained by the cosputtering and post-annealing. The absorption and photoluminescence spectra are presented. For our samples, a red luminescence peak analogous to that of porous Si is observed for films containing Si clusters rather than nanocrystals. Raman spectra which evidence the success in the heavy doping of B atoms into Si nanocrystals are also discussed.