Compositional Design of Mn ²⁺ ‐Activated Phosphors: Toward Narrow‐Band Green Emission for Wide Color Gamut Displays

Abstract High‐performance green‐emitting phosphors are vital for achieving a wide color gamut and high energy efficiency in next‐generation display backlighting. However, the simultaneous optimization of narrow emission bandwidth, high thermal stability, and strong quantum efficiency remains a persistent challenge, particularly in Mn 2+ activated systems. Here, a new narrow‐band green phosphor, Sr 2 ZnAl 22 O 36 :Mn 2+ (SZAO:Mn 2+ ) is reported, featuring exceptional color purity (≈90%) and a sharp emission centered at 516 nm (FWHM = 24 nm), efficiently excitable by blue light. Through targeted compositional engineering by substituting Zn 2+ with Mg 2+ and partially replacing O 2− with F − , the emission intensity is significantly enhanced (by 132%), the internal quantum efficiency is boosted nearly threefold, and remarkable anti‐thermal quenching behavior is achieved, with emission intensity reaching 109% at 423 K relative to room temperature. When integrated into a white LED prototype, SZAO: Mn 2+ enables a wide color gamut covering ≈124.5% of the NTSC standard, outperforming commercial β‐SiAlON:Eu 2+ . These results position SZAO:Mn 2+ as a compelling candidate for advanced display applications and demonstrate the effectiveness of compositional tuning in modulating the crystal field environment, offering a broadly applicable strategy for the design of next‐generation narrow‐band phosphors.