Synthesis and photoluminescence characteristics of Dy3+ doped NaY(WO4)2 phosphors

The novel phosphor powders of NaY(WO4)(2) doped with Dy3+ were synthesized by solid state reaction. X-ray diffraction analysis showed that the phosphors sintered at 900 degrees C for 6 h were a pure NaY(WO4)(2) phase for all the Dy3+ doping concentrations. The room temperature excitation spectra of the phosphors vary with the Dy3+ concentration and consist of an intense charge transfer band of WO42- groups and weak f-f transition absorption peaks of Dy3+. The photoluminescence spectra, excited at the peak wavelength of charge transfer band, exhibit three bands centered at 488, 575 and 662 nm, which originate from the transitions of F-4(9/2) -> H-6(15/2) (blue), F-4(9/2) -> H-6(13/2) (yellow) and F-4(9/2) -> H-6(11/2) (red) of Dy3+, respectively. The effects of Dy3+ concentration on luminescence intensity and the yellow-to-blue intensity ratio of the phosphors were investigated. The different behaviors for the doping concentration dependence of luminescence intensity resulted from the different kinds of excitation was discussed. (c) 2012 Elsevier Ltd. All rights reserved.