白光LED用Eu^3+掺杂的Li3Ba2Tb3(WO4)8高纯度红色荧光粉

High color purity red phosphor Li3Ba2Tb3(1-x)(WO4)8∶x Eu^3+for White LED

采用高温固相法制备出了一系列Li3Ba2Tb3-x(WO4)8∶x Eu 3+(x=0.01~0.06)红色荧光粉,利用x射线、光致发光光谱(PL)和荧光热稳定性等对其结构和发光性能进行了分析表征.实验结果表明,Eu 3+较好地掺入到了Li3Ba2Tb3(WO4)8结构中去,成为了良好的发光中心,在487 nm的蓝光激发下,616 nm处有对应于Eu^3+的5D0→7F2跃迁的强烈橙红光发射.发射光谱的变化规律表明,随着Eu^3+掺杂量的变化,存在Tb^3+到Eu^3+的有效能量转移,且在x=0.05时荧光强度达到最大值.荧光粉的热释性结果显示,在接近275℃时其荧光性能才开始明显衰减,表明此类荧光粉具有较高的热稳定性.因此,Li3Ba2Tb3-x(WO4)8∶x Eu3+(x=0.01~0.06)是一种具有良好应用前景的红色荧光粉.

A series of Li3Ba2Tb3-x(WO4)8∶x Eu^3+(x=0.01~0.06)red phosphors were prepared by a high temperature solid state reaction.X-ray diffraction,photoluminescence(PL)spectra and fluorescent thermal stability analysis were utilized to characterize the structure and luminescence properties of phosphors.The experimental results show that Eu 3+is well incorporated into the Li 3Ba 2Tb 3(WO 4)8 structure and becomes a good luminescent center,the phosphors can be efficiently excited by 487 nm light,and exhibit a red emissions corresponding to 5D0→7F2 transitions of Eu^3+at the main emission peaks of 616 nm.The variation of the emission spectrum indicates that there is an effective energy transfer of Tb^3+to Eu 3+with the change of Eu^3+doping amount,and the fluorescence intensity reaches the maximum at x=0.05.The pyrophoric results of the phosphors showed that the fluorescence performance began to decrease obviously near 275℃,indicating that the phosphors have higher thermal stability.In summary,Li3Ba2Tb3-x(WO 4)8∶x Eu^3+(x=0.01~0.06)is a promising red phosphor.