Towards efficient blue Eu2+ activated pyrophosphate phosphor for warm white LED applications

A blue-emitting LiCsBaP2O7:Eu2+(LCBPO:Eu2+) pyrophosphate phosphor prepared by solid-state synthesis that emits bright blue light with a first-rate internal quantum efficiency and high color purity is reported. Furthermore, when heated from 298 K to 473 K, LCBPO:0.015Eu2+ phosphor exhibits excellent color stability. Impressively, LCBPO:0.015Eu2+ blue phosphor exhibits exceptional stability against air exposure over a month. Fabricating a near-ultraviolet (n-UV) pumped pc-wLED using LCBPO:0.015Eu2+ along with green (Sr,Ba)2SiO4: Eu2+ and red (Ca,Sr)AlSiN3:Eu2+ phosphors demonstrates a well distributed warm white light with a high color rendering index (Ra) of 91.7, a low correlated color temperature (CCT) of 3382 K and a high luminous efficiency (LE) of 26.1 l m/W. The high-performance optical characteristics, straightforward synthesis procedures and economical initial materials cost of LCBPO:Eu2+ support the potential of this material for usage in warm white LED-based lighting systems.