SiO_2 thin films containing Si_(1-x)Ge_x quantum dots (QDs) are prepared by ion implantation and annealingtreatment. The photoluminescence (PL) and microstructural properties of thin films are investigated. Thesamples exhibit strong PL in the wavelength range of 400—470 nm and relatively weak PL peaks at 730and 780 nm at room temperature. Blue shift is found for the 400-nm PL peak, and the intensity increasesinitially and then decreases with the increase of Ge-doping dose. We propose that the 400—470 nm PLband originates from multiple luminescence centers, and the 730- and 780-nm PL peaks are ascribed tothe Si=O and GeO luminescence centers.
