Rapid sintering of high-efficiency phosphor-in-glass films for laser-driven light source.

Wang, Pengfei; Lin, Hang; Chen, Guoxin; Weng, Weitong; Xu, Yue; Lin, Yi; Xu, Ju; Cheng, Yao et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

The development of advanced high-power-density laser-driven light source requires durable and color-tunable inorganic phosphor-in-glass film composites as color converter. One challenge remains for the phosphor-in-glass film is the thermal erosion and degradation of phosphor, as harsh condition or long duration time is required to densify the film for conventional sintering. Here we develop a rapid thermal annealing technique that achieves high film densification (porosity < 3%) within seconds utilizing high-power (>10 kW) infrared irradiation. As demonstrated by high-resolution electron microscopy observation, a trivial interfacial reaction occurs, leading to almost intact phosphor particles and thus restrained luminous loss. For instance, the red-emitting Sr<sub>0.8</sub>Ca<sub>0.2</sub>AlSiN<sub>3</sub>:Eu<sup>2+</sup> exhibits a record internal quantum efficiency of 91.2% in the processed film and achieves a luminous flux of 2379 lm and efficacy of 140 lm W<sup>-1</sup> after fabricating a phosphor wheel. This method reduces energy consumption, enables high-throughput screening, and offers material universality and design flexibility, paving the way for new opto-functional materials and applications.