A comparative study of the photoluminescence properties of a-SiO :H film and silicon nanocrystallites

Photoluminescence (PL) properties in a-SiOx and silicon crystallites with nanometer dimensions were compared to investigate recombination processes and to reveal the effect of a-SiOx on silicon crystallites. The PL spectra and temperature dependence of PL intensity of a-SiOx (where x>1) and silicon crystallites surrounded by SiOx layer shared some similarities. These results indicate that the PL peak found near 1.6 eV has its origin in the SiOx layer at the surface of the silicon core. Recombination processes are discussed by temperature dependence and lifetime of PL spectra. The PL intensity of silicon crystallites at room temperature originates from reduction of the non-radiative recombination probability rather than increase in the radiative one.