Lattice Distortion‐Induced Performance Enhancement of Red Phosphors for White LEDs
Tiantian Guo, Yongtao Li, Yanxuan Ren, Xiaotong Yang, Xuejian Zhang, Xin Yu, Xiaoxue Li, Yue Che, Jian Luan, C. K. MahadevanABSTRACT
Modulating the local coordination environment of the luminescent centers represents a compelling strategy for designing high‐performance red phosphors. However, it remains challenging for Eu‐doped phosphors to simultaneously achieve high internal quantum efficiency and negative thermal quenching performance. In this work, Ca 2 AlNbO 6 was selected as the matrix. The spatial arrangement of the Ca sites provides relatively separated substitutional positions for Eu, contributing to the high optimal Eu concentration of x = 0.18. At the optimized W concentration (y = 0.02), W incorporation modifies the local crystal field of Eu through structural coupling and enhances the local lattice rigidity. As a result, the phosphor exhibits a 3.98‐fold enhancement in emission intensity, an internal quantum efficiency of 98.2%, and an emission intensity of 121% at 423 K relative to that at 303 K. The fabricated white light‐emitting diode (WLED) presents a color temperature of 4238 K, and a color rendering index of 92.1. This work provides a feasible strategy for simultaneously optimizing luminescence efficiency and thermal stability in Eu − activated double‐perovskite phosphors.