KBaScSi₃O₉:Eu²⁺ Glass‐Ceramics as Single‐Phase High‐Power White Emitters

Abstract Single‐phase white‐light emitters in the lighting technology overcome the challenges of re‐absorption and color shift. However, achieving the broadband white emission in single‐phase phosphor remains a challenge. Here, crystallized KBaScSi₃O₉:Eu²⁺ (KBSSO:Eu²⁺) glass‐ceramics (GC) with abundant cationic sites have been developed and an ultra‐broad emission band ranging from 460 to 800 nm have been found, in which the asymmetric green emission is ascribed to the Eu²⁺ ions in [KO₈] and [BaO₇] polyhedra, while the red emission centered at 620 nm is originated from Eu²⁺ ions in [ScO₆] sites. The optimized GC‐converted white LED (WLED) exhibits a high color rendering index (R_a = 89.8) and low correlated color temperature (CCT = 4241 K). Moreover, the encapsulant‐free GCc‐WLED can operate continuously under high drive currents. This work paves the way for the design and future development of single‐phase high‐power white light sources.