发光二极管用红色荧光粉Sr0.8-xBaxEu0.2WO4的制备和性质研究

采用化学共沉淀法制备了不同Ba²⁺掺杂浓度、 不同煅烧温度的Sr_0.8-xBa_xEu_0.2WO₄红色荧光粉. 研究了样品的晶体取向和晶格 畸变对发光性质的影响, 实验结果表明: 合成的Sr_0.8-xBa_xEu_0.2WO₄红色荧光粉为四方相, 样品中Eu³⁺的⁵D₀–⁷F₂跃迁的红光能被近紫外光和蓝光有效激发. 适量的Ba²⁺离子取代部分的Sr²⁺提高了Sr_0.8Eu_0.2WO₄荧光粉的发光强度, Ba²⁺掺杂浓度的改变对基质的晶格参数、晶体对称性和发光性能影响较大, Ba²⁺的最佳掺杂量为30%.

Preparation and luminescent properties of Sr0.8-xBaxEu0.2WO4 red phosphors for white LED

Sr_0.8-xBa_xEu_0.2WO₄ red phosphors with different Ba²⁺ doping concentrations is prepared by the co-precipitation method at different sintering temperatures. We study the influences of the crystal orientation and lattice distortion of the samples on the luminescence property. The results show that the Sr_0.8-xBa_xEu_0.2WO₄ synthesized by the process has a phase with tetragonal structure and that the red emission ⁵D₀-⁷F₂ of Eu³⁺ in the sample can be excited effectively by the near-UV light and blue light. The part of Sr²⁺ replaced with Ba²⁺ leads to the increase in emission intensity of Sr_0.8-xBa_xEu_0.2WO₄. The doping concentration of Ba²⁺ has a great influence on the crystal parameter, the crystal symmetry and the luminescent property. The optimized doping concentration of Ba²⁺ is found to be 30%.