Nature of visible luminescence of co-sputtered Si-SiOx systems

Photoluminescence (PL) spectra and Raman scattering spectra of Si-SiOx systems, prepared by radio frequency magnetron sputtering method and thermal annealed at 1150 deg. C for creation of Si nano-crystallites, were investigated as a function of Si content and Si nano-crystallite sizes. It was shown that the PL spectrum of such systems consists of several bands with peak positions at 1.32-1.34, 1.42-1.58, 1.77, 2.05 and 2.30 eV. The dependencies of these PL band parameters on concentration and size of Si nano-crystallites in the Si-SiOx system have been investigated and analyzed. The nature of radiative optical transitions for all PL bands is discussed