Modulation of optical performances of YAG:Ce glass-ceramics for laser-driven lighting through doping with high thermal conductivity AlN

The inadequate dissipation of heat and the suboptimal color quality of phosphor converters have been identified as critical constraints in the implementation of laser-driven lighting technology. In recent years, laser lighting has attracted significant attention as a pivotal direction for next-generation illumination systems. However, the thermal quenching effect induced by high-power blue laser sources significantly reduces the emission efficiency of phosphors, presenting a critical challenge that demands urgent resolution. In this study, we successfully fabricated AlN-YAG:Ce composite amorphous spheres by using the non-container solidification technique. The theoretical thermal conductivity of the glass-ceramic with 15 wt% AlN added was 23.13 W/(m∙K). Addressing the inherent limitation of weak luminescent properties in amorphous materials, crystallization treatment was implemented while preserving their advantageous characteristics. The amorphous crystallization treatment was found to be a successful method of achieving controllable optimization of high-efficiency luminescent performance. This objective was achieved through significantly enhancing emission efficiency via localized crystallization (formation of nanocrystalline or microcrystalline structures) in amorphous materials. Through systematic optimization and evaluation, the 15% AlN-YAG:Ce crystallized at 951 °Cglass-ceramic sample with an optimized thickness of 1 mm exhibited exceptional performance: under 1 W/mm 2 blue laser excitation, it achieved a luminous efficacy of 335.3 lm/W with a blue light absorptivity of 89.7% and a low correlated color temperature of 4405.4 K. The technology employed for the composite glass-ceramic's preparation offers a novel solution for the advancement of laser lighting technology.