Hydrothermal synthesis of spherical and hollow Gd 2O 3:Eu 3+ phosphors

Abstract

Spherical and submicrometer-sized hollow Gd 2O 3:Eu 3+ phosphors were prepared by homogeneous precipitation and hydrothermal method by varying the concentrations of reactants and changing the synthesis conditions. In the precipitation step, the spherical nucleus was formed and grew to large particles. In the hydrothermal step, the large particles crystallized to solid or hollow spheres. At last, Gd 2O 3:Eu 3+ phosphors were obtained by annealing at the temperature more than 600 °C. The deduced mechanics of forming the solid and hollow spheres was proposed. And the obtained spherical Gd 2O 3:Eu 3+ phosphors had better red luminescence properties. The relative luminescence intensity and the lifetime increased with increasing annealing temperatures.