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.