Enhanced cyan emission via competitive site occupancy engineering in Sr2SiO4:Eu2+ phosphor for achieving full-spectrum LED lighting

Highly efficient containing cyan-emitting phosphors are used to bridge the cyan cavity for near ultraviolet (NUV) light-emitting diodes (LEDs) to obtain high-quality full-spectrum white lighting. In this work, a series of Sr 2-x Na x Si 1-x Nb x O 4 :Eu 2+ (x = 0–0.25) (SNSNO:Eu 2+ ) solid solution phosphors were prepared by a solid-state reaction method. The bright SNSNO:Eu 2+ phosphors were proceeded to fill the cyan gap. Such a cosubstitution of Na + -Nb 5+ ion pair improves the cyan sub-band emission peaking at around 500 nm owing to the competitive site occupancy of Eu 2+ on the Sr 2+ site. Notably, codoping Na + -Nb 5+ ion pairs into the host can realize a tuning of spectrum of SNSNO:Eu 2+ from yellow-green to cyan-green region by crystallographic site engineering. Finally, employing mixture of SNSNO:Eu 2+ and commercial BAM:Eu 2+ and CaAlSiN 3 :Eu 2+ coated on a 365 nm NUV chip, a full spectrum wLED package with remarkable color rendering index (Ra = 95.1) and low CCT = 3167 K was generated. The results indicate that the SNSNO:Eu 2+ phosphor is very significative on closing the cyan gap for full-spectrum white lighting. • A series of SNSNO:Eu 2+ solid solution phosphors were proposed. • This solid solution phosphor emit bright cyan light by codoping Na + -Nb 5+ . • A full-spectrum w-LED device with remarkable Ra = 95.1 and low CCT = 3167 K was generated employing the SNSNO:Eu 2+ (x = 0.15) phosphor. • This solid solution phosphor exhibits an excellent thermal stability.