Engineering mixed polyanion red-emitting Rb2Bi(PO4)(WO4):Eu3+ phosphors with negligible thermal quenching and high quantum yield

Abstract

The high-performance red-emitting phosphors are strongly demanded as the next generation solid state lighting materials. Benefitting from the favorable accommodation capacity of polyanions and high charge transfer energy state in the structure, the pure red-emitting Rb2Bi(PO4)(WO4):Eu3+ (RBPWO:Eu3+) materials with negligible thermal quenching and high quantum yield were synthesized. RBPWO:Eu3+ has high absolute quantum yields of 88.1% and exceptional thermal stability of 98.6% integral retention at 423 K relative to the initial value at 298 K. Additionally, affected by the low symmetry crystalline-field of D2h, the title phosphors exhibit intense absorption band peaking at 394 nm and pure red light with the color CIE values (0.6482, 0.3515). The white light-emitting diode (w-LED) device fabricated from the title material exhibits low correlated color temperature (4000 K), high color rendering index (Ra = 90) and moderate luminous efficiency (18.07 lm/W) in the preliminary experiment. The present work indicates that the RBPWO:Eu3+ phosphors are promising red components for the near ultraviolet light excited w-LEDs.