Influence of Radiation on the Luminescence of Silicon Nanocrystals Embedded into SiO2 Film

Influence of gamma-irradiation on light emission properties of silicon nanocrystals imbedded into SiO2 filmis investigated. It was shown that small doses of gamma-irradiation (10(3)-10(5) rad) lead to enhancement of photoluminescence intensity in the nc-Si/SiO2 samples. This effect was explained by radiation induced passivation of recombination active centers on the nanocrystals surface. High doses of irradiation (similar to 10(7) rad) lead to the photoluminescence intensity decrease up to 2 times. Radiation treatment of silicon oxide films with embedded amorphous silicon inclusions resulted only in the decrease of the photoluminescence intensity within the whole range of doses (10(3)-5 x 10(7) rad). Radiation defects resulting in partial quenching of photoluminescence are characterized with the distributed activation energy of annealing with the peak position at similar to 0.96eV and the frequency factor 10(7) s(-1). The nature of such defects and the mechanisms of their creation are discussed.