BaWO4∶Eu3+红色荧光粉的水热制备及其发光性能

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。

Hydrothermal Preparation of BaWO4:Eu3+ Red Phosphor and Its Luminescent Properties

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%.