Opto-Thermal Enhancement of Phosphor-In-Glass Utilizing Nano Boron-Coated Copper Micropillar Substrate

Phosphor-in-glass (PIG) has attracted much attention in white light laser lighting due to its cost-effectiveness and ease of manufacture, while is challenging to simultaneously improve the opto-thermal management. Herein, we developed a universal strategy of nano boron nitride-coated copper micropillar substrate (nBN/CMS) to fabricate highly stable and efficient PIGs. The copper micropillars embedding PIG film serve as the effective heat transfer channels, and the nBN coating effectively solves the light absorption loss of copper micropillars. Results indicate that the temperature of nBN/CMS-PIGs is 219 °C lower than that of pure PIGs (8.48 W light input), and the increase of laser threshold is 68.5%. In addition, the luminous efficiency of nBN/CMS-PIGs is also enhanced by 20.3% compared to pure PIGs. Through comprehensive optimization of opto-thermal management, the maximum luminous flux of nBN/CMS-PIGs is observed to increase by 68.5% compared to pure PIGs, with optimized PIGs maintaining a robust luminous efficiency during a high-power reliability test lasting over 600 min. The nBN/CMS strategy provides a feasible solution for simultaneously achieving high optical efficiency and stability of PIGs, greatly accelerating the application in high-power laser lighting.