白光LED用红色发光粉LiGd(MoO_4))2:Eu~(3+)的制备和发光特性

采用高温固相法制备了LiGd1-xEux(MoO4)2钼酸盐红色发光粉,利用XRD和发光光谱技术对粉体进行了性能表征。结果表明:该系列发光粉均为四方晶系的白钨矿结构,能够被近紫外光(395nm)有效激发,产生Eu3+的5D0→7F2特征跃迁红光发射(616nm)。x=0.4时,即LiGd0.6Eu0.4(MoO4)2样品的发光强度超过商用红粉Y2O2S:Eu3+发光强度的5倍,虽然比未加入Gd样品LiEu(MoO4)2的发光强度略低,但LiGd0.6Eu0.4-(MoO4)2样品的组分中却减少了60%的Eu用量,明显降低了原料成本,更具实用价值,有希望成为白光发光二极管的红色发光材料。

Synthesis and Luminescent Properties of LiGd(MoO4)2 : Eu3+ Red Phosphors for White LEDs

A series of novel red light-emitting phosphors LiGd1-xEux(MoO4)2 were synthesized by solid-state reaction at high temperature. Their structure and luminescent properties were investigated in detail. The XRD patterns showed that all the phosphors are isostructural and share a tetragonal scheelite structure of space group I41/a88. In the emission spectra of the phosphors, the predominant transition emission is 5D0→7F2 (616 nm) of Eu3+, whereas the other emissions are very weak. The excitation spectra are composed of ligand-to-metal charge transfer bands (CTB) of Mo6+-O2-, as well as a few excitation transitions of Eu3+ between 4f levels. The LiGd0.6Eu0.4(MoO4)2 phosphor shows very strong emission intensity in comparison with commercial phosphor Y2O2S ∶ Eu3+. Although the fluorescence intensity of LiGd0.6Eu0.4(MoO4)2 is slightly lower than that of the LiEu(MoO4)2 , the content over 60% Eu3+ is saved. Therefore, the LiGd0.6Eu0.4(MoO4)2 phosphor significantly reduces the cost of raw materials. It might be a potential candidate for white LED application.