Sr <sub>3</sub> Lu (VO <sub>4</sub> ) <sub>3</sub> : Eu <sup>3+</sup> red‐emitting phosphors for warm white LEDs
Xianju Zhou, Jie Zhang, Lingni Chen, Yanhong Li, Guotao Xiang, Sha Jiang, Li Li, Xiao Tang, Zhong‐Min Cao, Guangxin Xie
Abstract
Abstract A series of novel red emission phosphors Sr 3 Lu 1‐ x (VO 4 ) 3 : x Eu 3+ ( x = 0.007, 0.009, 0.02, 0.04, 0.06) were synthesized successfully by traditional high‐temperature solid‐state reaction. The results of X‐ray diffraction (XRD) reveal the doped Eu 3+ ions have replaced the lattice sites of Lu 3+ ions. The diffuse reflectance spectra illustrate the energy gap of Sr 3 Lu(VO 4 ) 3 host is 3.61 eV. The room‐temperature steady‐state fluorescence spectra show that these phosphors can be effectively pumped by the charge‐transfer band (CTB) of the host in near ultraviolet (NUV) spectral region and then produce strong and pure red emission at 615 nm originated from 5 D 0 → 7 F 2 electric dipole transition of Eu 3+ . The Commission Internationale de L’Eclairage (CIE) coordinates of Sr 3 Lu 0.96 (VO 4 ) 3 :0.04Eu 3+ are (x = 0.65, y = 0.35), which are very close to the red standard of National Television Standards Committee NTSC (0.67, 0.33). The fabricated warm white‐light‐emitting diodes (LED) demonstrate high color‐rendering index Ra as 93. The results imply the red‐emitting Sr 3 Lu(VO 4 ) 3 :Eu 3+ phosphors could be potentially utilized in the fields of solid‐state lighting.