Narrow‐band green‐emitting RbSr 4 (BO 3 ) 3 :Eu 2+ phosphor paving the way for high‐performance multipurpose WLED applications

Abstract It remains a formidable challenge to develop narrow‐band green‐emitting phosphor for white light‐emitting diodes (WLED) lighting and wide color gamut displays, because the commercial β ‐SiAlON:Eu 2+ green phosphor still suffers from problems such as dissatisfactory peak position, not narrow enough emission band (full width at half maximum, FWHM≈55 nm), harsh synthesis condition and high price. Herein, a novel narrow‐band green‐emitting RbSr 4‐ x (BO 3 ) 3 xEu 2+ (RSBO:xEu 2+ ) phosphor ( λ em = 535 nm, FWHM = 45 nm), which can be efficiently pumped by blue‐light, was synthesized by a convenient solid‐state method at 800°C. The representative RSBO:0.015Eu 2+ exhibits high color purity (93.9%), excellent thermal stability (65%@423 K) and robust chromaticity stability (Δ E = 1.32 × 10 −2 @423 K). Furthermore, RSBO:0.015Eu 2+ possesses remarkable chemical stability, whose emission intensity remains almost unchanged after being exposed to the ambient atmosphere for 15 days. More importantly, the WLED prototype device using this green phosphor can produce high‐quality warm white light with low correlated color temperature (CCT = 3670 K) and high color rendering index ( Ra = 92). Furthermore, it achieved 98% of the National Television Systems Commission (NTSC) color space according to the CIE 1931 standards. All the results collectively demonstrate that RSBO:Eu 2+ phosphor can be considered as a potential next‐generation green phosphor for high‐performance WLED lighting and wide color gamut display technology.