3D-hierachical spherical LuVO4:Tm3+,Dy3+,Eu3+ microcrystal: Synthesis, energy transfer, and tunable color

A series of color-tunable emitting LuVO4:Tm3+,Dy3+,Eu3+ microspheres were successfully synthesized by a solvothermal process. The structure was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results revealed that the sample is pure tetragonal phase of LuVO4 and consists of 3D-hierachical microspheres with the diameter about 2 μm. Additionally, the possible formation mechanism of microspheres was proposed. Furthermore, the photoluminescence properties of LuVO4:Dy3+,Eu3+ samples were investigated in detail. Both blue and yellow emissions corresponding to the 4F9/2-6H15/2, 4F9/2-6H13/2 transition of Dy3+ ions and red emission corresponding to the 5D0-7FJ (J = 1, 2, 3, 4) transition of Eu3+ ions can be observed in LuVO4:Dy3+,Eu3+ phosphors under 366 nm near-ultraviolet radiation. The energy transfer process between Dy3+ and Eu3+ was demonstrated to be resonant type via dipole-quadrupole mechanism. Additionally, when co-doping Dy3+ with Tm3+ or Eu3+ or tri-doping Tm3+,Dy3+,Eu3+ ions in the single component, the colorful emitting can be obtained by giving abundant blue, green, red, yellow, orange, especially white-light-emission. This type of color-tunable luminescence phosphors may have promising application in solid state lighting application.