From blue to cyan emission: Ce3+ and Tb3+ co-doped silicon phosphate phosphors with high thermal stability

摘要

A series of Ca-15(PO4)(2)(SiO4)(6):xCe(3+),yTb(3+) phosphors have been prepared by a high-temperature solid-state reaction. Under the excitation of near-UV with 371 nm wavelength, Ca-15(PO4)(2)(SiO4)(6):xCe(3+) phosphors exhibit strong blue emission with a broad peak at 432 nm. Based on the photoluminescence of Ca-15(PO4)(2)(SiO4)(6):xCe(3+) phosphors, the coordination environment around Ce3+ ions and the concentration quenching mechanism are inferred. With the doping of Tb3+ ions into Ca-15(PO4)(2)(SiO4)(6):1.33%Ce3+, the luminescence color from blue to cyan can be well tuned. By measuring the luminescence intensity and lifetime of the as-prepared phosphors, it can be judged that there exists an energy transfer from Ce3+ to Tb3+. To achieve white light, the optimal Ca-15(PO4)(2)(SiO4)(6):1.33%Ce3+, 9%Tb3+ phosphors are mixed with commercial SrAlSiN3:Eu2+ powders and finally warm white light emission could be obtained. The results show that Ca-15(PO4)(2)(SiO4)(6):xCe(3+),yTb(3+) phosphors have potential applications in warm white light-emitting diodes.