Photoluminescence Properties of Novel Host-Sensitized Y6WO12:Dy3+ Phosphors

Novel host-sensitized Y6WO12:xDy(3+) (0.01 <= x <= 0.20) phosphors were synthesized via solid-state reaction process. X-ray diffraction analysis confirmed the phase formation of Y6WO12:Dy3+ materials. The photoluminescence excitation and emission spectra, concentration effect, thermal-quenching, and decay properties were investigated. The phosphor could be excited by the UV light region from 300 to 400 nm, and it exhibited blue (478 nm) and yellow (568 nm) emission corresponding to F-4(9/2)-H-6(15/2) transitions and F-4(9/2)-H-6(13/2) transitions, respectively. The WO6 groups in the host lattices can absorb UV light efficiently, and then transferred the energy to the activator Dy3+ ions, resulting in near white light emission. The optimum dopant concentration of Dy3+ ions in Y6WO12:xDy(3+) was around 5 mol% and the critical transfer distance of Dy3+ was calculated as 12 angstrom. The fluorescence lifetime was also determined in Y6WO12:0.05Dy(3+). The temperature dependence of photoluminescence properties was investigated from 300 to 480 K and the prepared Y6WO12:Dy3+ phosphors showed poor thermal-quenching properties.