Photoluminescence characterization and energy transfer of color-tunable Li6Y(BO3)3:Ce3+,Tb3+ phosphors

Ce3+ and Tb3+ singly doped and co-doped Li6Y(BO3)3 (LYB) phosphors were synthesized through a solid-state reaction. The phosphors were effectively excited by 350 nm, which matched the near-UV emitting InGaN chip. Luminescence spectra and decay lifetime curves of LYB:Ce3+,Tb3+ were measured to prove energy transfer from Ce3+ to Tb3+. Through energy transfer, the intensity of the typical emission peak of Tb3+ at 546 nm in LYB:0.05Ce3+,0.03Tb3+ was approximately 1.8 times stronger than that in LYB:0.03Tb3+. The mechanism of Ce3+→Tb3+ energy transfer was a dipole–dipole interaction, and the energy transfer efficiency gradually increased to 29.27% with increasing Tb3+ doping concentration. Furthermore, the emission colors of LYB:Ce3+,Tb3+ varied from blue to green by adjusting the Ce3+/Tb3+ ratio, indicating that the phosphors could be used as blue-to-green emitting phosphors for application in ultraviolet light-emitting diodes.