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摘要在本论文中，我们采用自助溶剂法制备了Eu2+、F-共掺的不刺眼(Ca0.5,Sr0.5)7(SiO3)6Cl2荧光粉。利用XRD，荧光光谱仪、SEM等测试手段对荧光粉的结构、形貌及发光性能进行表征。结果表明：在F-掺杂情况下，通过自助溶剂还原法在950℃即可合成结晶度高的荧光粉，荧光粉颗粒度均匀性好，便于涂覆；在338nm激发下，随F-浓度增加，560nm处的黄光发射降低，480nm处的蓝光发射升高，发光强度变低，当F-含量70%时，荧光粉色坐标为(0.337，0.3763)，发白光。当F-掺杂后，硅卤酸盐基质发生畸变，Eu2+在硅卤酸盐基质中存在两种取代格位，两种格位之间存在能量传递，通过这种能量传递实现白光发射。这种通过调控基质材料方法为白光LED的发展开拓一种新思路。57638
关键词：自助溶剂法；白光；氢气还原；碳还原
Abstract
In this paper, the Eu2+ and F- codoping(Ca0.5, Sr0.5)7(SiO3)6Cl2phosphor have been successfully prepared with self-flux method.A series of measurements including XRD ，SEM and Photoluminescence(PL) are employed to detect the microstructure, the morphology and the optical property of the as-prepared phosphor. The results indicate that the well-crystallized (Ca0.5, Sr0.5)7(SiO3)6Cl2 host can been shaped at the lower temperature with the CaF2 asfluxagent, and the particles exhibit well dispersed morphology. When excited by 338nm, with the increase of F- concentration, the PL emission intensity located at 560nm declines, and the peak intensity ascribed to blue light at 480nm increase. When the F- concentration is upto 70%, the xy CIE chromaticity coordinates of (Ca0.475,Sr0.5Eu0.025)7(SiO3)6Cl0.6F1.4 phosphor is presented at(0.337，0.3763), located at the white reign. This phenomenon can be explained that when the F- in inserted into the host, the PL property have been tailored due to the distorted co-ordination field. Herein, the Eu2+ ions occupies two sensitive sites, and the energy transfer have been occurred between two light centers, and the white light is produced. The way to modify the hosts to obtain the white light opens a new door to the development of white LED.
Keywords:self-flux method; white hair; hydrogen reduction; carbon reduction
目录
1 绪论 1
1.1 引言 1
1.2白光LED荧光粉 2
1.2.1 发光材料的发光原理 2
1.2.2 稀土发光 2
1.2.3 稀土发光的优点 3
1.2.4 稀土材料在LED中的应用 4
1.3 白光LED荧光粉技术发展现状 4
1.4 白光LED研究的目的与意义 5
1.5 荧光粉常见的制备方法 6
1.5.1 自助溶剂法 6
1.5.2 高温固相法 6
1.5.3 溶胶-凝胶法 7
1.6 论文设计思路 7
2实验 8
2.1 实验部分 8
2.2 试验用仪器 8
2.3荧光粉样品制备 8
2.3.1 碳还原制备(Ca1-z -y,SrzEuy)7(SiO3)6Cl2-2xF2x 8
2.3.2 氢气还原制备(Ca1-z -y,SrzEuy)7(SiO3)6Cl2-2xF2x 9
2.4 样品表征 10
2.4.1 X射线衍射仪测试 10
2.4.2 扫描电镜测试