Synthesis of green-emitting (Gd, La, Tb)2O(WO4)2 phosphors

• (Gd,La,Tb)2O(WO4)2 phosphors were synthesized by the solid-state reaction method.
• The emission intensity was effectively enhanced by the La3+ doping into the host.
• The highest emission intensity was obtained for (Gd0.87La0.03Tb0.10)2O(WO4)2.

Green-emitting (Gd1−x−yLaxTby)2O(WO4)2 (0 ⩽ x ⩽ 0.05, 0.05 ⩽ y ⩽ 0.15) phosphors were synthesized in a single phase form by the conventional solid-state reaction method, and their photoluminescent properties were characterized. The (Gd1−x−yLaxTby)2O(WO4)2 phosphors showed strong and broad excitation bands from 230 to 350 nm, corresponding to the energy transition from the 4f8 to 4f75d configuration of Tb3+ and the charge-transfer (CT) transition of O2−−W6+. The oxytungstate phosphors exhibited typical emission peaks assigned to the transition from 5D4 to 7FJ (J = 6, 5, 4, and 3) of Tb3+, and the luminescence emission intensity was effectively enhanced by the La3+ doping into the host Gd2O(WO4)2 lattice. The highest green emission intensity was obtained for (Gd0.87La0.03Tb0.10)2O(WO4)2, where the relative emission intensity was 63% that of a commercial green-emitting (La0.52Ce0.31Tb0.17)PO4 phosphor.