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A comprehensive comparative study of SiO 2 and Al 2 O 3 oxide layers with Si nanocrystals formed by Si + ion implantation and high temperature annealing has been performed. Information on morphology, phase composition, structure, and luminescent properties of ensembles of ion synthesized silicon nanocrys tals has been obtained using confocal Raman microscopy, X ray diffraction, Fourier transform infrared spec troscopy, electron paramagnetic resonance, and photoluminescence. It has been found that the peculiarities of the formation of nanocrystals, the distribution of nanocrystals over the depth of the implanted layer, the structure, and the character of chemical bonds are similar for both types of oxide matrices; however, the pho toluminescence in the wavelength range 600-1000 nm, which is caused by the nanocrystals in the Al 2 O 3 matrix, has been observed only in the case of the formation of SiO 2 shells around the Si nanocrystals. The surface oxidation of the Si nanocrystals, which is necessary for the formation of SiO 2 shells, is possible due to the presence of excess oxygen in the Al 2 O 3 matrix (the case of Si implantation into the deposited Al 2 O 3 film), as well as due to the inflow of oxygen from the annealing atmosphere (the case of Si implantation into sap phire). In order to verify the quantum confinement mechanism of luminescence, available data on the tem perature dependence of the photoluminescence intensity have been analyzed. An analysis of the mechanisms of charge transfer and electroluminescence excitation in diode structures based on thin ion synthesized layers with silicon nanocrystals has also been performed.

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