Voitovych М. Radiation-induced effects in silicon oxide films with silicon nanoinclusions

Influence of radiation and radiation-thermal treatments on structural and light-emitting properties of silicon oxide films with embedded silicon nanoinclusions. It was shown firstly that small doses (1000-100000 rad) of gamma-irradiation lead to enhancement of photo-luminescence intensity in nc-Si/SiO2 samples. This effect was explained by radiation-induced passivation of recombination centers on the nanocrystalls surface. It was shown that after high doses (~10000000 rad) of irradiation photo-luminescence intensity decreased up to 2 times. Radiation treatment of silicon oxide films with embedded amorphous silicon inclusions resulted in photo-luminescence intensity decrease within the whole (1000-10000000 rad) range of doses. Radiation defects which bring to partial quenching of photo-luminescence are characterized with distributed activation energy of annealing with peak position at 0,96 eV and frequency factor of 10000000 1/s. Nature of such defects and mechanisms of their creation are discussed. The effect of significant (up to 25 times) photoluminescence enhancement was detected on the nc-Si/SiО2 samples which were irradiated with doses of 10000000 rad and additionally treated by isochronal annealing (200 - 500 С) in the inert atmosphere or were annealed at the temperature of 450 С in the hydrogen ambient. The mechanism of radiation-thermal photoluminescence intensity increase was suggested.