Engineering the Glass Network to Eliminate Interfacial Reactions in CaAlSiN3:Eu2+ Phosphor-in-Glass for High-Power White Lighting and Amber Laser Lighting

Thermally induced interfacial reactions between nitride phosphors and glass matrices remain a critical bottleneck in the development of high-performance phosphor-in-glass (PiG) for high-power LED and laser-driven lighting applications. Herein, we address this challenge by the rational glass design to reconcile its glass transition temperature (T g ), structural stabilization and chemical compatibility. By establishing a correlation between structural evolution and interfacial diffusion, we develop a six-component glass matrix (CaF 2 -Al 2 O 3 -SiO 2 -B 2 O 3 -Na 2 O-P 2 O 5 ) featuring a low T g (∼453°C) and high chemical inertness. This glass matrix effectively alleviates the thermal degradation of embedded CaAlSiN 3 :Eu 2+ (CASN:Eu 2+ ) phosphors and suppresses interfacial reactions. The resulting CASN:Eu 2+ -PiG achieves a high internal quantum efficiency of ∼96%, and its fluorescence lifetime is relatively reduced by only 0.02 µs. A wLED incorporating Y 3 Al 5 O 12 :Ce 3+ and CASN:Eu 2+ in the PiG exhibits a high color rendering index of 90.4 while maintaining a luminous efficiency of 93.1 lm/W. Furthermore, by tuning the (Y,Gd) 3 Al 5 O 12 :Ce 3+ /CASN:Eu 2+ ratio in the PiG film, laser-driven amber light is achieved for specialized lighting, with a maximum luminous flux of 536.0 lm and a peak luminous efficiency of 101.6 lm/W. This work presents a universal strategy for designing chemically robust, low-melting glass to advance PiG applications in high-power solid-state lighting and specialty light sources.