High‐Efficiency Red‐Emitting Phosphor‐In‐Glass Films for Laser‐Driven Lighting and Display

Abstract Laser‐driven phosphor‐converted lighting and display technologies offer exceptional energy efficiency and superior performance. However, the development of high‐quality white light sources with both excellent color rendering and high brightness remains a significant challenge due to the scarcity of red‐emitting color converters that maintain high efficiency and stability under high laser powder densities. In this study, (Sr, Ca)AlSiN 3 : Eu 2+ (SCASN:Eu) phosphor‐in‐glass films (PiGFs), emitting from 610 to 680 nm, are fabricated on Al 2 O 3 ceramic substrates with minimal interfacial reactions. All PiGFs exhibited excellent densification and maintained high IQE, losses in IQE remaining below 10 % relative to the original phosphor. Notably, the PiGF with an emission peak at 653 nm achieved a lumen density of 206 lm mm −2 @ 23.6 W mm −2 due to its high thermal conductivity (22 W m −1 K −1 ) and low IQE loss. Under rotating excitation, it reached a record 786 lm mm −2 @ 90.6 W mm −2 . Furthermore, a spatially separated YAGG:Ce‐CASN:Eu “phosphor wheel” in reflective mode produced a luminous flux of 1125 lm @ 23.6 W mm −2 , a correlated color temperature (CCT) of 6653 K, a color rendering index (CRI) of 86, and CIE coordinates (0.308, 0.338), enabling long‐distance illumination and projection display. This work offers a promising strategy for developing high‐efficiency color converters for advanced laser‐based lighting and display applications.