采用水热法, 通过变化水热反应时间制备出不同的BaWO4∶Eu3+样品, 利用XRD和SEM分析了样品的晶体结构和表面形貌, 研究了基质晶体生长取向对BaWO4中Eu3+离子特征发射的影响。实验结果表明: BaWO4∶Eu3+样品在395 nm近紫外光或464 nm蓝光激发下发射578, 592, 612 nm的红光, 其中612 nm(5D0→7F2)发射强度明显高于592 nm (5D0→7F1)。在水热温度160 ℃的情况下, 所制备的样品均为四方相, 不同的水热反应时间将影响晶体在各晶向的生长速度, 进而影响晶体的对称性和发光性能。水热时间为10 h时的发射强度最大。

The red phosphor powders BaWO4∶16%Eu3+ were successfully prepared by hydrothermal method in different hydrothermal time. The crystal structure and surface morphology of the phosphor as-prepared was characterized by XRD patterns and SEM, respectively. The correlation between the crystal orientation of the matrix and the characteristic emission of the doped rare earth ions Eu3+ were discussed. The pure phase structure BaWO4∶16%Eu3+ phosphor was obtained under the hydrothermal reaction at 160 ℃. The room temperature characteristic emission 5D0→7F0 and 5D0→7FJ(J=1, 2)of Eu3+ ions in the samples as-prepared were observed under the excitation of 395 nm or 464 nm light. 5D0→7F2 transition emission intensity was significantly higher than those of 5D0→7F1 and 5D0→7F0. XRD analysis indicates that the samples prepared at a hydrothermal temperature of 160 ℃ are all tetragonal. The growth rates of each crystal face vary with different hydrothermal time. This difference leads to a change of crystal symmetry and the luminescent properties of BaWO4∶Eu3+ samples. The optimized hydrothermal time is 10 h for the Eu3+ doping concentration of 16%.