Luminescence properties of Eu~（3＋）：NaGd（WO_4_）2 nanoparticles and nanorods

The NaGd（WO_4）_2：Eu~（3＋） phosphors were prepared by the microemulsion mediated hydrothermal method. The morphology and size of the samples could be dependent on the p H in the initial solution. These phosphors obtained had a strong absorption at 395 nm matching with the popular emission of near-UV LED chips, and could emit intense red light at 616 nm. The small ellipsoid-like particles or short rods were provided with large parameters of oscillator strength ？_2 and asymmetry ratio. Compared to the ellipsoid-like phosphors, the rod-like phosphors took on stronger emission, longer lifetime and larger quantum efficiency. This work demonstrated that the one-dimension Na Gd（WO_4）_2：Eu~（3＋） phosphors might be a more favorable device than zero-dimension ones for photoluminescence.