Narrow‐Band Green‐Emitting RbSr ₄ (BO ₃ ) ₃ :Eu ²⁺ Phosphor Glass Composite for Wide‐Color‐Gamut Laser Displays

ABSTRACT Laser phosphor display is promising for next‐generation high‐quality display technology due to its high brightness, wide color gamut, and low speckle. However, the lack of high performance narrow‐band green emitters with robust laser resistance remains a critical bottleneck. Herein, we develop RbSr 4 (BO 3 ) 3 :Eu 2+ (RSBO:Eu 2+ ) as a narrow‐band green emitter, which exhibits an emission peak at 526 nm with a narrow full width at half maximum of only 50 nm under blue light excitation. The highly dense and rigid host framework effectively suppresses lattice relaxation and electron–phonon coupling despite Eu 2+ occupying multiple cation sites in RSBO. Highly stable RSBO:Eu 2+ was further embedded into a low‐melting P 2 O 5 ‐Al 2 O 3 ‐B 2 O 3 ‐Na 2 O glass matrix to fabricate a phosphor‐glass composite (RSBO:Eu‐PGC), demonstrating good thermal stability and a high saturation threshold exceeding 40 W/mm 2 . The corresponding rotating phosphor wheel maintained a low surface temperature of 79.9°C under 40 W/mm 2 blue‐laser irradiation, effectively mitigating thermal degradation. A prototype laser display system using a rotating wheel integrating RSBO:Eu‐PGC and K 2 SiF 6 :Mn 4+ ‐PGC achieved a wide color gamut of 107% National Television System Committee (NTSC) standard, which highlights the great potential of narrow‐band green‐emitting RSBO:Eu‐PGC for laser phosphor display applications.