Enhancing thermal performance in laser-driven illumination with metal-micropillars array three-dimensional substrate

Laser-driven illumination is a promising candidate for next-generation high-power lighting. The thermal quenching of light-converting materials is among the most urgent problems to be solved. The typical method used to address this issue involves the use of substrates with high thermal conductivity to enhance heat dissi-pation. However, heat transfer from the top surface to the bottom substrate is challenging because of the poor heat transfer capability of phosphor-in-glass (PIG), which severely limits the illumination performance. In this study, a simple and effective three-dimensional (3D) substrate with a metal-micropillars array was fabricated to form phosphor-in-metal-glass (PIMG) for laser-driven illumination. Appropriate simulations and experiments indicated that the metal-micropillars act as effective internal heat transfer channels in the PIMG, thereby ensuring heat transfer from the top surface to the bottom substrate with high thermal conductivity and without impediments. Owing to the improved thermal management, the temperature of PIMG is only 138 degrees C at 7.46 W irradiation, which is 193 degrees C (58.3 %) lower than that of the reference PIG with a planar substrate. Consequently, the maximum luminous flux of the PIMG is 46.4 % higher than that of the reference PIG because of the increase in the threshold laser power, and the correlated color temperature (CCT) is stable at 4300 K. This implies that metal substrates with high thermal conductivity can maximize the heat transfer advantage by simply improving their 3D structures, which provides a viable scheme for high-power laser-driven illumination.