Luminescence properties of Ce3+and Tb3+ ions codoped strontium borate phosphate phosphors

The Ce3+-activated, Tb3+-activated, and Ce3+ and Tb3+ co-activated phosphors 2SrO–nB2O3–(1−n)P2O5 were synthesized by the solid-state reaction. The structures, photoluminescent spectra and dynamics of them were systemically studied. The results demonstrate that the structure of the samples with n=0.10–0.50 belongs to the hexagonal phase. When n is beyond this range, the structures are the mixed phases of α-Sr2P2O7 and Sr2B2O5. The optimum composition is determined to be n=0.25 for the 2SrO–nB2O3–(1−n)P2O5 phosphors. As n varies from 0.01 to 0.50, the lifetime of Ce3+ ion increases gradually, while the lifetime of Tb3+ ion decreases, indicating that the energy transfer efficiency decreases with the increase of n. The ET efficiency between Ce3+ and Tb3+ in the optimum composition reaches to 70%. The present results demonstrate that the Ce3+ and Tb3+ co-activated hexagonal 2SrO–0.25B2O3–0.75P2O5 powders can possibly be applied as the newly developed green efficient phosphors in the field of lighting and display.