Hydrothermal Synthesis of Europium Activated Terbium Tungstate Phosphors: Controllable Morphologies and the Tunable Luminescent Property

摘要

Phosphors of europium activated terbium tungstate (Tb2 (WO4)3:Eu~(3+)) were successfully prepared by hydrothermal method with the subsequent calcination treatment. The precursors presented flower-like microstructures assembled from many nanoflakes, and various morphologies were obtained by controlling the reaction parameters. Tb2(WO4)3:Eu~(3+) phosphors show outstanding luminescent properties with tunable emission colors under ultraviolet (UV) excitation, owing to the efficient energy transfer from WO4 ~(2-) to Tb~(3+) to Eu~(3+). As the doped Eu~(3+) content increases, the emission colors of Tb2(WO4)3:Eu~(3+) phosphors can be altered from green,yellow to red. Particularly, the energy transfer mechanism (WO4 ~(2-)->Tb~(3+)->Eu~(3+)) has been investigated further based on a few theoretical simulations, finding that the process mainly takes place via the dipole-dipole interaction. Due to the efficient energy transfer in Tb2 (WO4)3:Eu~(3+) phosphors, multicolor emissions could be achieved in a single host material by adjusting the doped Eu~(3+) content. The facile preparation route and the outstanding tunable luminescent properties render the materials as promising candidate phosphors applied in future color displays and light-emitting devices.