Photoluminescence, photoluminescence excitation and Raman spectra of Si/SiOx layers were measured as a function of Si content. Samples were prepared by co-sputtering Si and SiO2, and post-annealing. The average size of Si nano-particles was estimated from Raman measurements. It was shown that, in general, the photoluminescence spectra consisted of 2 bands with maxima in the 'red' and 'green' spectral ranges. The 'red' photoluminescence band was complex and contains 2 (infra-red and red) components. The shift of the peak position of the infra-red component from 1.38 to 1.54eV correlated with a decrease in the Si nano-particle size, from 5 to 2.7nm. It was shown that this photoluminescence component could be attributed to carrier recombination in Si nano-particles. The R component of the 'red' band as well as the 'green' band exhibited similar dependences of the peak positions and intensities upon the Si content and could be attributed to defect-related luminescence. It was concluded that the light absorption in Si nanocrystallites plays the main role in the photoluminescence excitation process. Hot-carrier participation in the excitation of defect-related bands was deduced.

Defect-Related Luminescence of Si/SiO2 Layers. L.Khomenkova, N.Korsunska, T.Torchynska, V.Yukhimchuk, B.Jumayev, A.Many, Y.Goldstein, E.Savir, J.Jedrzejewski: Journal of Physics - Condensed Matter, 2002, 14[48], 13217-21