Robust YAG:Ce single crystal for ultra-high efficiency laser lighting

At present, solid-state laser-driven lighting fabricated with blue laser diode (LD) and phosphor has been greatly developed in high-power lighting applications. The major obstacle is the luminescence saturation threshold of the fluorescence conversion material (YAG:Ce). In this work, we successfully prepared a series of high-quality and robust YAG:Ce single crystals. With high quantum efficiency (QE = 92%), regular crystal structure and high thermal conductivity, the single-crystal has excellent ability to deal with high radiation flux and thermal accumulation generated by high power. Matching the single-crystal with the laser, the luminous efficiency up to 274 lm/W and saturation threshold of 12 W/mm2 were obtained. In addition, the influence of Ce doping concentration and sample processing conditions on the indicators in laser-driven white lighting was systematically studied. The results are of great significance and are believed to promote the development of solid-state laser-driven lighting.