Strong and pure red-emitting Eu3+-doped phosphor with excellent thermal stability for warm WLEDs

Abstract

Red-emitting phosphor, as an indispensable part of high-quality white-light-emitting diodes (WLEDs), has received extensive research attention. A red-emitting Eu³⁺-doped LiYO₂ phosphor with excellent luminescence properties was prepared by solid phase reaction. Under the optimal excitation of 395 nm, the specimens displayed strong and pure red emission, the optimal doping concentration and color purity were 0.20 and as high as 98.9%, and the dipole–dipole interaction was found to be responsible for concentration quenching. According to crystallographic structure and Judd–Ofelt theory analysis, the Eu³⁺ ions were located at a low symmetry site, thereby obtaining a high bright red emission. Furthermore, the obtained LiYO₂:0.20Eu³⁺ sample possesses outstanding emission thermal stability. Finally, a packaged WLED device based on a LiYO₂:0.20Eu³⁺ phosphor with excellent performance was obtained. These results indicate that the as-prepared phosphor has potential for high-quality lighting applications.