Li+离子掺杂对红色发光材料Y2(W,Mo)O6:Eu3+发光性能的影响

采用高温固相法制备了荧光粉Y2-x(W,Mo)O6:Eu3+,xLi+,利用X射线衍射仪和电子扫描显微镜对样品的结构和形貌进行了表征,并利用荧光光谱法分析了样品的光谱特性.首先在Y2WO6中掺入少量的Mo6+离子,掺入Mo6+后增加了原Y2WO6:Eu3+的激发光谱在近紫外光区的吸收,扩展了激发光谱的谱宽,但却使Y2W...

Photoluminescence Properties of Y_2(W,Mo)O_6:Eu~(3+) Incorporated with Li~+ Ions

The photoluminescence properties of Y_2-x (W,Mo)O₆ ∶ Eu³⁺, xLi⁺ were investigated in this paper. The excitation spectra of Y₂(W,Mo)O₆ ∶ Eu³⁺ showed two broad excitation bands at 290 and 368 nm which were attributable to the O^2- → W⁶⁺ and O^2- → Mo⁶⁺ transitions, respectively. The excitation band edge moved from 370 nm to 450 nm with the incorporation of Mo⁶⁺ ions. The emission spectra exhibited two weak lines at 588, 593 nm owing to the ⁵D₀ → ⁷F₁ transition, and strong sharp peak at about 610 nm owing to the⁵D₀ → ⁷F₂ transition of the Eu³⁺ ion. Moreover, the bluish-green luminescence of the WO^6-₆ group corresponding to the ³T_1u→¹A_1u transition was also observed in these compounds. The emission of the WO^6-₆ decreases with the increasing concentration of Mo⁶⁺ in Y₂(W,Mo)O₆ ∶ Eu³⁺ due to the energy transfer with the process WO^6-₆→MoO^6-₆. As a result, pure red color emission was obtained with the incorporation of Mo⁶⁺ ions. However, the emission intensities of Y₂(W,Mo)O₆ ∶ Eu³⁺ decreased with incorporation of Mo⁶⁺ ions. In order to enhance the emission intensities of Y₂(W,Mo)O₆ ∶ Eu³⁺, Li⁺ ions were introduced into Y₂(W,Mo)O₆ ∶ Eu³⁺. The red luminescence of Eu³⁺ in Y₂(W,Mo)O₆ was greatly enhanced after codoping monovalent alkali metal ions Li⁺ into the lattice. The morphology of powder particles was characterized by scanning electron microscope. The incorporation of Li⁺ increased the particle grain size. The hexagonal crystalline of the Y₂(W,Mo)O₆ ∶ Eu³⁺, Li⁺ powder had a preferred growth orientation. It was speculated that the Li⁺ ions may serve as a selfpromoter for better crystallization or as a lubricant for the complete incorporation of the Eu³⁺ ions into the host lattice, and it resulted to the enhancemednt of PL of Y₂(W,Mo)O₃ ∶ Eu³⁺.This study showed that the red phosphor, Y₂(W,Mo)O₆ ∶ Eu³⁺ incorporated with Li⁺ ions was advantageous for LEDs application.