Sr3Lu (VO4)3: Eu3+ red‐emitting phosphors for warm white LEDs

Abstract

AbstractA series of novel red emission phosphors Sr3Lu1‐x(VO4)3:xEu3+(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 Eu3+ ions have replaced the lattice sites of Lu3+ ions. The diffuse reflectance spectra illustrate the energy gap of Sr3Lu(VO4)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 5D0 → 7F2 electric dipole transition of Eu3+. The Commission Internationale de L’Eclairage (CIE) coordinates of Sr3Lu0.96(VO4)3:0.04Eu3+ 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 Sr3Lu(VO4)3:Eu3+ phosphors could be potentially utilized in the fields of solid‐state lighting.