Dependency of photoluminescence from SiO<sub>2</sub> thin f ilms containing Si<sub>1-x</sub>Ge<sub>x</sub> quantum dots on Ge/Si doping ratio

Abstract

SiOlsubg2l/subg thin films containing Silsubg1-xl/subgGelsubgxl/subg quantum dots (QDs) are prepared by ion implantation and annealing treatment. The photoluminescence (PL) and microstructural properties of thin films are investigated. The samples exhibit strong PL in the wavelength range of 400?470 nm and relatively weak PL peaks at 730 and 780 nm at room temperature. Blue shift is found for the 400-nm PL peak, and the intensity increases initially and then decreases with the increase of Ge-doping dose. We propose that the 400?470 nm PL band originates from multiple luminescence centers, and the 730- and 780-nm PL peaks are ascribed to the Si=O and GeO luminescence centers.