Be²⁺‐Induced Red Emission Enhancement in CaAl₁₂O₁₉:Mn⁴⁺ for Wide Color Gamut Display: Suppressing Self‐Reduction of Mn⁴⁺ to Mn²⁺

Abstract Mn 4+ ‐activated CaAl 12 O 19 (CAO: ) is recognized as a promising candidate for red phosphor used in wide color gamut displays. However, the spontaneous self‐reduction of to 2+ occurs charge compensation through ‐Mn substitution Al 3+ ‐Al , lowering quantum efficiency . To suppress self‐reduction, some divalent metal ions, including Ba Sr Cd Zn and Mg are added instead but only small luminescence enhancement observed. In this paper, remarkable CAO: via co‐doping Be reported. The photoluminescence properties studied function doping concentration, optimal concentration 0.01 found. internal 74.9% external 56.3% achieved under UV excitation, higher than those other ions. This study indicates that addition dominates because closer size backlight light‐emitting diodes using fabricated, exhibiting 110.1% Nation Television Standards Committee (NTSC) gamut, wider both current commercial K 2 SiF 6 : (KSF) conventional one YAG yellow phosphor.