Samples with layer of silicon nanocrystals embedded in SiO2 (the single phase Si content in oxide ranged between 5 and 92 volume %) were subjected to high energy ion implantation. Implantation-induced modifications of SiO2-ncSi properties discussed in this paper include a shift of the major ncSi-related photoluminescence peak and intensification of the high-photon energy peaks, that accompany the change in amount and type of the charge trapped on the nanocrystals. A unified model is suggested for all these phenomena.