Novel narrowband emitting red phosphor Sr3La2W2O12:Eu3+ with excellent thermal stability for WLEDs

The development of red phosphors with good thermal stability, high quantum yield and high color purity is still a big challenge. In this work, a series of novel red phosphors Sr3La2W2O12:Eu3+ (0 <= x <= 0.18, triangle x = 0.03) were successfully prepared by high-temperature solid-phase method. The phosphors reveal a hexagonal phase with the space group of R-3 m. The phosphor Sr3La2W2O12:Eu3+ produced narrowband red emission from 5D0 -> 7F2 of Eu3+ (616 nm) under excitation at 395 nm, 465 nm, and 533 nm. Importantly, phosphor Sr3La2W2O12:Eu3+ exhibits astonishing quantum efficiency (IQE = 89.60%, EQE = 41.52%), and it demonstrate robust thermal performance with the emission intensity retaining 92.73% at 558 K of that at 298 K. Finally, the prepared red phosphor Sr3La2W2O12:Eu3+ and yellow phosphor YAG:Ce(3+ )were combined with a blue LED chip (460 nm) to form a WLED device, which presented warm white light with color coordinates of (0.3523, 0.3732), color rendering index of 83.7, and color temperature of 4826 K.