近紫外光激发黄色荧光粉Ba_3Y_4O_9∶Dy^(3+)的制备及发光特性

Preparation and Luminescence Properties of Yellow Phosphors Ba_3Y_4O_9∶Dy^(3+) Excited by Near UV Light

通过高温固相法合成了一系列Ba_3Y_(4-x)O_9∶x Dy^(3+)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Dy^(3+)掺杂浓度对样品发光性质的影响,发现样品的发光随着Dy^(3+)浓度的增大而增强,但光谱形状基本保持不变,表明Dy^(3+)占据了基质中低对称性的Y^(3+)格位。当Dy^(3+)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Dy^(3+)浓度的增大逐渐减小,进一步证明了Dy^(3+)离子之间存在着能量传递现象。Ba_3Y_4O_9∶Dy^(3+)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。

The phosphor Ba 3Y 4-x O 9∶x Dy 3+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 Ba 3Y 4O 9∶Dy 3+phosphors were measured,which were in the yellow region.The effect of the doping concentration of Dy 3+was investigated,and found the samples of luminescence intensity increased with the increasing of the concentration of Dy 3+,but the spectral shape basic remains the same.This indicates that Dy 3+occupies the Y 3+position of low symmetry in the matrix.The concentration quenching occurred when x=0.08 for Ba 3Y 4-x O 9:x Dy 3+phosphor and its mechanism is ascribed to dipole-dipole interaction.The decay time of the phosphor decreases with the increase of Dy 3+-doped concentrations,this is further evidence that there exists a phenomenon of energy transfer between the Dy 3+ions.Ba 3Y 4O 9∶Dy 3+phosphors are located in the yellow region and have good thermal stability.