Photoluminescence from Zinc Oxide Quantum Dots Embedded in Silicon Dioxide Matrices

ZnO quantum dots (QDs) embedded in SiO2 matrix are fabricated by ion implantation and annealing treatment methods. When the Zn-doping dose is (2, 3, 5, and 7)x10(16)cm(-2), the size of quantum dots is in the range of approximate to 4-10nm in diameter according to the XRD and HR-TEM results. Ultraviolet and green light emissions from the specimen are obtained at room temperature. With the increase of the Zn-doping dose, the PL peak in the ultraviolet region red shifts from 3.32 to 3.10eV. This PL peak is related to the size of ZnO QDs, which is ascribed to the free exciton recombination in QDs. The green light emissions centered at 2.43 and 2.25eV are independent of the Zn-doping dose and annealing temperature, which are attributed to the deep-level defect and the small peroxy radical (SPR) defect, respectively.