Influence of Radiation on the Luminescence of Silicon Nanocrystals Embedded into SiO 2

Influence of γ-irradiation on light emission properties of silicon nanocrystals imbedded into SiO2 film is investigated. It was shown that small doses of γ-irradiation (103–105 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 (~107 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 (103–5 × 107 rad). Radiation defects resulting in partial quenching of photoluminescence are characterized with the distributed activation energy of annealing with the peak position at ~0.96 eV and the frequency factor 107 s−1. The nature of such defects and the mechanisms of their creation are discussed

СВОЙСТВА ПОРИСТЫХ ПЛЕНОЧНЫХ СТРУКТУР Si–КВАНТОВЫЕ ТОЧКИ/SiOx, ПОЛУЧЕННЫХ ПО ФТОРОВОДОРОДНОЙ ТЕХНОЛОГИИ

A detailed study of Si quantum dots/SiOx film structures synthesized using a new hydrofluoric technology of forming silicon nanoparticles in porous silicon oxide matrices has been performed. A physical mechanism of the effect of chemical treatment in HF vapors in air on the structural and luminescent properties of the film porous systems with nanosized silicon has been suggested. We show that the passivation of the broken bonds on the surface of Si nanoinclusions as a result of the treatment occurs with the participation of oxygen, fluorine and hydrogen atoms, and this effect depletes the nonradiative recombination channel by two orders of magnitude. We suggest a model explaining the blue shift of the photoluminescence spectra as a result of the treatment due to a decrease in the sizes of the Si−QD during the oxidation of their surface layers. Проведено детальное исследование пленочных структур Si−квантовые точки/SiOx, полученных по новой фтороводородной технологии формирования наночастиц кремния в пористой матрице оксида кремния. Предложен физический механизм влияния химической обработки в парах HF на воздухе на структурные и свето- излучающие свойства пленочных пористых систем с наноразмерным кремнием. Показано, что пассивация оборванных связей на поверхности Si−нановключений в результате обработки происходит при участии атомов кислорода, фтора и водорода, что на два порядка величины ослабляет безызлучательный канал рекомбинации. Предложена модель, объясняющая сдвиг спектра фотолюминесценции в область голубого свечения в результате обработки вследствие уменьшения размеров Si−квантовых точек при окислении их поверхностного слоя

Influence of Radiation on the Luminescence of Silicon Nanocrystals Embedded into SiO 2 Film

Influence of -irradiation on light emission properties of silicon nanocrystals imbedded into SiO 2 film is investigated. It was shown that small doses of -irradiation (10 3 -10 5 rad) lead to enhancement of photoluminescence intensity in the nc-Si/SiO 2 samples. This effect was explained by radiation induced passivation of recombination active centers on the nanocrystals surface. High doses of irradiation (∼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 × 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 ∼0.96 eV and the frequency factor 10 7 s −1 . The nature of such defects and the mechanisms of their creation are discussed