Ultra‐Narrowband Green‐Emitting Transparent Composite Ceramics for Laser‐Driven Display

Abstract Laser‐driven projection displays face a critical challenge in developing laser‐excitable and high‐performance narrowband green emitters. Herein, new Al₂O₃‐LaMgAl₁₁O₁₉: Mn²⁺ (Al₂O₃‐LMA: Mn²⁺) transparent composite ceramics are reported via high‐temperature vacuum sintering, which produces a high‐color‐purity (95.4%) green emission with full width at half maximum of 24 nm and superior thermal and moisture and laser irradiation stability. These are attributed to low electron‐phonon couple, weak crystal‐field effect, an individual lattice location of Mn²⁺ activators in high structural rigid host, and the incorporation of a high‐thermal‐conductivity Al₂O₃ secondary phase. As a result, the composite ceramics are demonstrated as an attractive color converter with a high external quantum efficiency (38%) and absorption coefficient (53%), which ensures a luminous flux of 2012 lm @40.0 W, a luminous efficacy of 67.7 lm W⁻¹, and a green light conversion efficiency of 20.3% upon blue laser irradiation. This enables to construct a brand‐new laser‐driven prototype display with a record color gamut beyond Rec.2020 standard (100.8%), outperforming commercial YAG: Ce³⁺ and β‐SiAlON: Eu²⁺. This exploration in ultra‐narrowband green luminescent materials is poised to accelerate the development of “ideal displays” for laser‐driven projection display technology.