Enhanced luminescence intensity of novel red-emitting phosphor -Sr3Lu2(BO3)4:Bi3+,Eu3+ via energy transfer

Bi3+/Eu3+ co-activated Sr3Lu2(BO3)4 was successfully synthesized via a solid state reaction. The optimal concentration of Bi3+,Eu3+ and Bi3+/Eu3+ are 1 mol%, 60 mol% and 1 mol%/20 mol%, respectively. The emission spectra of Sr3Lu2(BO3)4:Bi3+, Eu3+ gives three peaks located at 405 nm, 489 nm which were attributed to Bi3+ S6 (blue) and C2 (green) site symmetry, respectively and 610 nm which was ascribed to Eu3+ (5D0 → 7 F2) transition. The emission intensity of Bi3+ decreases with increasing Eu3+ content which indicates that a efficient energy transfer occurred in the Sr3Lu2(BO3)4 host. The relative intensity of Sr3Lu1.79(BO3)4:0.01Bi3+,0.20Eu3+ excited at 327 nm and 370 nm was remarkably enhanced by 201% and 265%, respectively, via the energy transfer from Bi3+ to Eu3+. The results indicate that Sr3Lu2(BO3)4:Bi3+, Eu3+ is a potential novel red-emitting phosphor for UV LED applications.