High-Efficiency Ultrathin Amber Phosphor-Glass Composites With Laminated Architecture for High-Power, Color-Stable Lighting

All-inorganic phosphor composites have emerged as vital solutions for high-power solid-state lighting, circumventing the intrinsic thermo-chemical vulnerabilities and spectral instabilities of conventional polymer-encapsulated matrices. Here, we report self-supporting, ultrathin phosphor-glass composites (PGC) utilizing commercial Ca-α-sialon:Eu 2+ amber phosphors as the luminescent component. Leveraging tape-casting and low-temperature sintering, we achieve microscale control over composite thickness (117 µm) and phosphor distribution, while maintaining crystalline integrity and delivering a high internal quantum yield of 95.59%. Systematic tuning of phosphor loading reveals that photon transport—governed by multiple scattering and self-absorption—is the dominant limiter of apparent emission in the ultrathin regime, with an optimal loading identified at 20 wt.%. Furthermore, we engineer a dual-layer laminated architecture that spatially decouples light conversion from mechanical reinforcement and thermal buffering. This configuration effectively suppresses chromatic drift and improves luminous stability and efficiency retention under high-power excitation. Notably, the laminated PGC exhibit superior tensile strength, moisture resistance, and thermal dissipation without compromising luminescence performance. These results establish architecture-enabled ultrathin PGC as a promising photonic packaging platform for next-generation color-stable, high-power solid-state lighting.