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采用固相法合成了白光LED用红色Na Gd_(1–x–y)Eu_xSm_y(WO_4)_2(x=0.05,0.10,0.15,0.20,0.25,0.30;y=0,0.01,0.02,0.03,0.04)系列荧光粉。分别采用X射线衍射、扫描电子显微镜、发光光谱等测试手段分析了粉体样品的物相、形貌与发光性质。结果表明:Na Gd(WO_4)_2的最佳合成温度为1 000℃,且在1 000℃合成的粉体的颗粒尺寸比较均匀,平均粒径在2~3μm左右。Na Gd_(1–x–y)Eu_xSm_y(WO_4)_2系列荧光粉均可被近紫外光(393 nm)和蓝光(464 nm)有效激发,其最强发射峰位于615 nm处,属于Eu~(3+)的~5D_0→~7F_2电偶极跃迁。并且由于Sm~(3+)和Eu~(3+)离子之间存在着有效的能量传递,使得Sm~(3+)的掺入能有效的增加Eu~(3+)的发光强度,Eu~(3+)和Sm~(3+)的最佳掺杂量分别为25%(摩尔分数)和2%。
The solid-state method was used to synthesize the red Na Gd_ (1-x-y) Eu_xSm_y (WO_4) _2 (x = 0.05,0.10,0.15,0.20,0.25,0.30; y = 0,0.01,0.02,0.03,0.04 ) Series of phosphors. The phase, morphology and luminescence properties of the powders were analyzed by X-ray diffraction, scanning electron microscopy and luminescence spectroscopy. The results show that the optimal synthesis temperature of Na Gd (WO_4) _2 is 1 000 ℃, and the particles synthesized at 1 000 ℃ have a uniform particle size of about 2 ~ 3 μm. All of the phosphors of Na Gd_ (1-x-y) Eu_xSm_y (WO_4) _2 series can be efficiently excited by near-UV light (393 nm) and blue light (464 nm) 3 +) ~ 5D_0 → ~ 7F_2 electric dipole transitions. In addition, due to the effective energy transfer between Sm 3+ and Eu 3+ ions, Sm 3+ can effectively increase the Eu 3+ luminescence intensity. Eu The optimum doping amounts of ~ (3+) and Sm ~ (3+) were 25% (mole fraction) and 2% respectively.