Preparation And Characterization Of Rare-earth Ions Doped Tungstate/Molybdate White Light Nano-materials

Rare earth luminescence materials are widely used in the fields of solid-state lighting, flat panel display, catalysis, laser devices and biological labeling. It is well known that tungstate and molybdate have excellent physical and chemical stability. In particular, rare earth ions doped tungstate and molybdate compounds exhibit wide luminescent properties, and they have been widely investigated in the phosphors for white light emitting diodes (LED). In this thesis, we have prepared the rare earth doped tungstate and molybdate luminescent materials via hydrothermal process. The main content is as follows:The phosphors of NaGd(MoO4)2:Dy3+,Eu+and NaGd(MoO4)2:Eu3+,Tb3+were prepared by a surfactant-assisted hydrothermal process. The results show that the phosphors have excellent white light emitting and tunable multiple emitting colors.The phosphors of the NaGd(MoO4)2-x(WO4)x:5%Dy3+and the NaGd(MoO4)2-x (WO4)x:5%Yb3+,2%Tb3+/2%Eu3+were synthesized by a facile hydrothermal method. The results show that the NaGd(MoO4)2-x(WO4)x:5%Dy3+phosphors have the near white light emitting; in the Yb3+and Tb3+codoped NaGd(MoO4)2-x(WO4)x phosphors, the upconversion luminescence of Tb3+is realized by doping of Yb3+ZnW04@CaMo04:Eu3+core-shell structure phosphors were prepared by hydrothermal method. The results show that the phosphors exhibit red light emitting properties, this provides a new way to prepare the core-shell structure phosphors for white LED.