High-brightness and high-color purity red-emitting Ca₃Lu(AlO)₃(BO₃)₄:Eu³⁺ phosphors with internal quantum efficiency close to unity for near-ultraviolet-based white-light-emitting diodes

Abstract

In this work, we reported on high-brightness Eu³⁺-activated Ca₃Lu(AlO)₃(BO₃)₄ (CLAB) red-emitting phosphors. Under 397 nm excitation, the CLAB:Eu³⁺ phosphors showed intense red emissions at around 621 nm with CIE coordinates of (0.657, 0.343). The optimal doping concentration of Eu³⁺ ions was found to be 30 mol. %, and the CLAB:0.3Eu³⁺ sample possessed high-color purity of 93% and ultra-high internal quantum efficiency as great as 98.5%. Importantly, the CLAB:0.3Eu³⁺ also had good thermal stability. Finally, a white-light-emitting diode (WLED) lamp with good color-rendering index was fabricated by using a 365 nm ultraviolet chip and the phosphor blends of CLAB:0.3Eu³⁺ red-emitting phosphors, (Ba,Sr)₂SiO₄:Eu²⁺ green-emitting phosphors, and BaMgAl₁₀O₇:Eu²⁺ blue-emitting phosphors.