Synthesis and photoluminescence of Tb3+ Activated NaY(WO4)2 phosphors

The novel yellowish green phosphor powders of NaY(WO4)2 doped with Tb3+ were prepared by solid-state reaction. The powder samples were characterized by X-ray diffraction and photoluminescence. X-ray diffraction analysis showed that the phosphors sintered at 900 °C for 6 h were a pure NaY(WO4)2 phase for all the Tb3+ doping concentrations. The room temperature excitation spectra vary with the Tb3+ concentration and consist of an intense charge transfer band of WO42− group and weak intra-4f8 transition absorption peaks of Tb3+ ions. The photoluminescence spectra, excited at the peak wavelengths of charge transfer bands, consist of the characteristic Tb3+ emission transitions from 5D3 and 5D4 excited levels to 7FJ (J = 3–6) levels. The dependence of luminescence intensity on the Tb3+ concentration in NaY(WO4)2:Tb phosphors was investigated.