采用高温固相法合成了La2-xMgTiO6∶xDy3+和La2-x-yMgTiO6∶xDy3+,yEu3+系列荧光粉, 通过X射线衍射对其相结构进行了表征, 优化了荧光粉的组成, 研究了Dy3+和Eu3+浓度对发光强度的影响, 测试了荧光粉的荧光光谱和寿命, 研究了Dy3+和Eu3+之间的能量传递机理和能量传递效率。结果表明: 所有合成的掺杂荧光粉均为单相物质; La2-xMgTiO6∶xDy3+最佳掺杂浓度为x=0.05; 在350 nm近紫外光激发下, La2-x-yMgTiO6∶xDy3+,yEu3+显示出Dy3+的特征黄、蓝光发射和Eu3+的特征红光发射; Dy3+的荧光寿命呈双指数衰减, 随着Eu3+浓度的增大, Dy3+的荧光寿命逐渐减小, 证明了Dy3+和Eu3+离子之间存在着能量传递; 能量传递效率随着Eu3+掺杂浓度的增加而增加, La1.83MgTiO6∶0.05Dy3+,0.12Eu3+荧光粉的能量传递效率为53.9%; 改变调节Eu3+的掺杂浓度可以得到从冷白色到暖白色的荧光粉, La1.83MgTiO6∶0.05Dy3+,0.12Eu3+的色坐标为(0.337 3, 0.354 4)。

A series of La2-xMgTiO6∶xDy3+ and La2-x-yMgTiO6∶xDy3+,yEu3+ phosphors were synthesized by high temperature solid-state method. The phase of the products was determined by X-ray diffraction meter and the composition of the phosphors was optimized. The influence of the concentration of Dy3+ and Eu3+ on the luminescence intensity was studied. The fluorescence spectra and fluorescence lifetime of the phosphors were tested. The energy transfer mechanism and energy transfer efficiency between Dy3+ and Eu3+ were studied. The results showed that all the as-synthesized doped phosphors were of single phase. The optimum doping concentration of Dy3+ in La2-xMgTiO6∶xDy3+ was x=0.05. The La2-x-yMgTiO6∶xDy3+,yEu3+ phosphors exhibited yellow and blue emissions of Dy3+ and characteristic emissions of Eu3+ upon 350 nm near ultraviolet light excitation. The fluorescence lifetime decay of Dy3+ was double exponential and it decreased with the increase of the concentration of Eu3+, which showed the occurrence of an energy transfer between Dy3+ and Eu3+. The energy transfer efficiency increased with the increase of the concentration of Eu3+, which was 53.9% for La1.83MgTiO6∶0.05Dy3+,0.12Eu3+. By adjusting the concentration of Dy3+ and Eu3+, the phosphor realized the emission from cold-white-light to warm-white-light. The chromaticity coordinates of La1.83MgTiO6∶0.05Dy3+,0.12Eu3+ were (0.3373, 0.3544).