Journal of Materials Science, Vol.51, No.7, 3545-3554, 2016
Luminescence properties of M-3(VO4)(2):Eu3+(M = Ca, Sr, Ba) phosphors
In this paper, M-3(VO4)(2):Eu3+(M = Ca, Sr, Ba) phosphors have been synthesized by high-temperature solid-state method. The phase composition and luminescence properties of the synthesized phosphors were characterized by X-ray powder diffraction and photoluminescence (PL) spectra, respectively. The influences of fluxing agent and doped concentration of rare-earth ions on PL properties of the phosphor were investigated. The results indicated that the energy transfers between VO4 (3-) and Eu3+ in the host occurred mainly via a dipole-dipole interaction mechanism. The increase in cation radius (from Ca2+ to Ba2+) in the host causes the emission peak originated from D-5(0) -> F-7(2) transition of Eu3+ shifting from 615 to 621 nm, as well as decreasing the fluorescence lifetimes of Eu3+ from 0.77 to 0.19 ms and changing the CIE chromaticity coordinates from the orange-red region to the white region. Moreover, the emission colors of Ba3-x (VO4)(2):xEu(3+) can be firstly adjusted from cyan region to white light region via controlling the concentration of Eu3+. Temperature-dependent luminescence spectra proved the good thermal stability of the as-prepared phosphor. This work shows the potential application of europium-doped samples in UV converted pc-WLEDs.