A promising all-inorganic green-emitting YAGG:Ce phosphor-in-glass for laser lighting

Abstract

Phosphor-in-glass (PiG) as a reliable color converter has drawn considerable attention in solid-state laser lighting. Here, a series of green-emitting Y₃Al_3.5Ga_1.5O₁₂:Ce (YAGG:Ce) PiG samples are fabricated via a solid-state reaction method. The microstructure, photoluminescence and thermal performance of the YAGG:Ce PiG samples are systematically investigated. Impressively, the optimized sample not only exhibits a superior internal quantum efficiency of 94% but also has a remarkable thermal conductivity of 2.5 W m⁻¹ K⁻¹. Moreover, it achieves excellent thermal stability (maintaining 81.2% of the room-temperature intensity at 473 K). Notably, the maximum luminous efficacy of the as-synthesized sample is 236.8 lm W⁻¹ under a blue laser power density of 2.77 W mm⁻². Furthermore, a prototype laser diode packaged with the high efficiency and robust YAGG:Ce PiG produces bright green light, indicating its enormous potential as a green color converter for application in laser-driven lighting.