Enhanced photoluminescence of Tb3+ in SnO2 film by phosphorus diffusion process

SnO2:Tb films on silicon wafers were prepared by DC reactive magnetron sputtering and ion-implantation. It was found that pure rutile polycrystalline SnO2 film with optical band gap of 4.0 eV was formed after high temperature annealing. Furthermore, defect-related light emission at 590 nm from the SnO2 substrate and the intra-4f transition from Tb3+ ions coexisted when the SnO2:Tb film was annealed at 1000 °C for 1 h after Tb3+ ion-implantation. The PL intensity of the D45→Fk7 (k = 6–3) transition of Tb3+ ion was greatly enhanced by the phosphorus diffusion treatment. It is proposed that the Tb3+ ions change from substitution sites to the enlarged interstitial sites in SnO2 host.