The effect of Lu3+ doping upon YAG:Ce phosphor ceramics for high-power white LEDs

Intense green emission is extremely significant to the color rendering index (CRI) of white LEDs. Various green-emitting YLuAG:Ce phosphor ceramics were successfully prepared by vacuum sintering. The effects of Lu3+ doping on structure and luminescence property were investigated in detail. In comparison with YAG:Ce, YLuAG:Ce ceramics own smaller grain size, better luminescence performance and higher thermal stability. The photoluminescence (PL) intensity of YLuAG:Ce ceramics increases by 23.6 % due to the "light scattering enhanced effect". Furthermore, the Ce3+ emission is obviously blue-shifting from 533 nm to 519 nm, and the intensity of YLuAG:Ce ceramics reduces only about 8.9 % at 250 °C, showing better thermal stability (vs 11.1 % of YAG:Ce). The LE of LED packaged by YLuAG:Ce ceramic is up to 148.88 lm/W when the doping Lu3+ y is 2.1. The above results show that tailored YLuAG:Ce phosphor ceramic is a potential green-emitting color converter for high-power LEDs (hp-LEDs).