Luminescent properties of Tb3+ activated double molybdates and tungstates

The phosphors, NaLa1−xTbx(MoO4)2 and NaLa1−xTbx(WO4)2, were prepared by the solid-state reaction. The structures and photoluminescent properties of the phosphors were studied. The result of XRD patterns indicates that these phosphors are of the similar scheelite-like (CaWO4) isostructure. The absence of concentration quenching of Tb3+ was observed in NaLa1−xTbx(WO4)2 by investigating their photoluminescent properties. This phenomenon has not been reported before, as we known. The phosphor NaTb(WO4)2 shows stronger green emission under 378 nm excitation with broader excitation band, compared with NaLa1−xTbx(MoO4)2.