近紫外光激发黄色荧光粉Ba3Y4O9：Dy3+的制备及发光特性

通过高温固相法合成了一系列Ba₃Y_4-xO₉：xDy³⁺荧光粉材料。利用X射线粉末衍射、荧光光谱和荧光寿命对样品进行了表征。实验表明，样品的激发光谱由一系列线状峰组成，峰值分别位于328，355，368，386，427，456，471 nm。在355 nm激发下，荧光粉在490 nm（⁴F_9/2→⁶H_15/2）和580 nm（⁴F_9/2→⁶H_13/2）处有很强的发射，发射光谱的色坐标位于黄光区域。研究了不同Dy³⁺掺杂浓度对样品发光性质的影响，发现样品的发光随着Dy³⁺浓度的增大而增强，但光谱形状基本保持不变，表明Dy³⁺占据了基质中低对称性的Y³⁺格位。当Dy³⁺摩尔分数x=0.08时出现发光强度猝灭现象，浓度猝灭机理为电偶极-电偶极相互作用。样品的发光寿命随着Dy³⁺浓度的增大逐渐减小，进一步证明了Dy³⁺离子之间存在着能量传递现象。Ba₃Y₄O₉：Dy³⁺荧光粉的发光位于黄光区域，有较好的热稳定性，是潜在的白光LED用荧光粉材料。

Preparation and Luminescence Properties of Yellow Phosphors Ba3Y4O9: Dy3+ Excited by Near UV Light

The phosphor Ba₃Y_4-xO₉:xDy³⁺ was synthesized by traditional high-temperature solid-state reaction method. The structure and luminescence properties were characterized using X-ray powder diffraction, photoluminescence spectra (PL) and fluorescence decay time. The results indicate that the excitation spectrum includes a series of linear peaks, located at 328, 355, 368, 386, 427, 456, 471 nm. The main emission peaks were located at 490 nm(⁴F_9/2→⁶H_15/2)and 580 nm(⁴F_9/2→⁶H_13/2) under 355 nm excitation. The chromaticity coordinates of Ba₃Y₄O₉:Dy³⁺ phosphors were measured, which were in the yellow region. The effect of the doping concentration of Dy³⁺ was investigated, and found the samples of luminescence intensity increased with the increasing of the concentration of Dy³⁺, but the spectral shape basic remains the same. This indicates that Dy³⁺ occupies the Y³⁺ position of low symmetry in the matrix. The concentration quenching occurred when x=0.08 for Ba₃Y_4-xO₉:xDy³⁺ phosphor and its mechanism is ascribed to dipole-dipole interaction. The decay time of the phosphor decreases with the increase of Dy³⁺-doped concentrations, this is further evidence that there exists a phenomenon of energy transfer between the Dy³⁺ ions. Ba₃Y₄O₉:Dy³⁺ phosphors are located in the yellow region and have good thermal stability.