Narrow-band green phosphor RbK2Na(Li3SiO4)4:Eu2+ with excellent thermal stability and high efficiency for wide color gamut displays†

The development of efficient and thermally stable narrow-band-emitting phosphors is crucial for wide color gamut display applications. Herein, we have developed a novel narrow-band green-emitting RbK₂Na(Li₃SiO₄)₄:Eu²⁺ phosphor with remarkable luminescence properties. The phosphor exhibits a main green emission band at 535 nm, with a narrow full width at half maximum of 51 nm, attributed to its unique rigid structure and highly symmetric cationic sites. Furthermore, it demonstrates excellent thermal stability, retaining 90.95% of the integrated emission intensity at 500 K compared to that at 100 K, and exhibits a high internal quantum efficiency of 82.51%. By combining RbK₂Na(Li₃SiO₄)₄:5%Eu²⁺ with commercial red K₂SiF₆:Mn⁴⁺ phosphors and blue GaN chips, a white light-emitting diode device with a wide color gamut (103% NTSC) was prepared, demonstrating the potential of the RbK₂Na(Li₃SiO₄)₄:Eu²⁺ phosphor for liquid-crystal backlight applications.