【作者】 刘晴；

【导师】 李友芬；

【作者基本信息】 北京化工大学 ， 材料纳米技术， 2007， 硕士

【摘要】 随着平板显示器如场发射显示器和真空荧光显示器的发展，阴极发光材料的要求也越来越高。为了得到高亮度，高效率的荧光粉，基质材料的选择是比较重要的一个环节。氧化物荧光粉就因为其良好的热稳定性广泛受到关注。而镓酸盐由于具有更好的化学稳定性，较窄的禁带宽度，更适合用来作为荧光粉材料。本文通过溶胶—凝胶法和固相法分别合成了ZnGa₂O₄和SrGa₂O₄荧光粉。讨论了不同类型的激活剂（Eu，V，Mo，In，Y，Al），敏化剂，煅烧温度，保温时间和激活剂浓度对荧光粉发光性能的影响。利用X射线衍射（XRD）分析相结构和组成，荧光分光荧光计（PL）检测发光性能，TG-DTA分析反应过程，SEM观察了发光粉的形貌，实验结果表明：（1）通过柠檬酸溶胶-凝胶法可合成出ZnGa₂O₄∶Eu荧光体，当Zn∶Ga为1∶4时，所得成品的最强发射峰位于613nm处，说明Eu³⁺离子占据了非反演对称中心的位置，属于Eu³⁺特征⁵D₀→⁷F₂跃迁，其对应于红色光谱。而通过添加不同的敏化剂，在ZnGa₂O₄∶R∶Eu（R∶Ba，Sr，In，Mo，V）中，能有效提高发光强度。（2）采用固相法合成SrGa₂O₄荧光粉，XRD结果表明：SrGa₂O₄属单斜晶系，晶胞参数a=9.43（?），b=9.00（?），c=8.39（?），β=89.06°，属P2₁／n（No．14）空间群。光谱数据表明：SrGa₂O₄∶Eu³⁺荧光粉的发射主峰在610nm，Eu³⁺离子占据了非反演对称中心的位置。当Eu³⁺离子浓度大于1mol％时，位于590，610nm附近的2个发射峰均出现劈裂现象，即有2个⁵D₀→⁷F₁（586，597nm）、2个⁵D₀→⁷F₂（609，615nm）发射峰，⁷F₂劈裂出两个分支的强度比例随Eu³⁺浓度的变化而变化。（3）采用固相反应法合成了SrGa₂O₄∶Eu∶Gd，Gd作为Eu的敏化剂与Eu之间存在能量迁移，其最强发射峰位于613nm，属于Eu³⁺离子的⁵D₀→⁷F₂跃迁，发光强度得到增强。（4）固相法合成Zn_0.5Sr_0.5Ga₂O₄∶Eu荧光粉。Zn_0.5Sr_0.5Ga₂O₄∶0.02Eu的发光强度最佳。更多还原

【Abstract】 The development of flat panel display devices such as field emission displays （FEDs） and vacuum fluorescent displays （VFDs） requires highly efficient cathodoluminescent materials. It is important for the bright and efficient phosphor to choose the group material. Oxide phosphor is noticed because of the excellent heat stability. Gallate have high chemical stability and narrow band-gap, so it fit to be used as phosphor. This paper reported the synthesis of phosphor ZnGa₂O₄ and ZnGa₂O₄ and discussed the influences of activator, sensitizer, calcined temperatures, duration, and concentrations of activator on luminescent properties. Phase compositions and luminescent properties of the phosphors were investigated and detected by using XRD and phosphor luminometer （PL）. The reaction process is analyzed by the TG-DTA and the appearance of the phosphor is observed by SEM.（1） ZnGa₂O₄:Eu phosphor is synthesized by the sol-gel process , which is completely reacted with ratio of Zn : Ga=l : 4．The main peak at 610 nm can be ascribed to ⁵D₀→F of Eu³⁺ , corresponding to red light. Eu³⁺ ion occupies a site with lacking inversion symmetry in ZnGaO host lattice. It could be change the luminescent intensity by（2） The Eu³⁺ doped SrGa₂O₄ phosphor was prepared with the conventional solid state reaction method. The phase composition was characterized by powder X-ray diffractometry. The result shows that the producing powder belongs to monoclinic crystal system with its lattice constants: a=9．43（?）, b=9．00（?）, c=8．39（?）,β=89．06°, and with space group P21/ n （No. 14） . The excitation and emission spectra were measured. The main peak at 610nm can be ascribed to the electric dipole transition ⁵D₀→⁷F₂, which indicates that Eu³⁺ occupies a site lacking inversion symmetry. The peaks at 590nm and 610nm transition emission split to two peaks respectively, ⁵D₀→⁷F₁, （586, 597nm） and ⁵D₀→⁷F₂ （609, 615nm） due to the crystal-field in the conditions of concentration of Eu with more than 1%. The strength ratio of two parts for the splitting peak ⁷F₂can be changed according to the concentration of Eu.（3） The phosphor of SrGa₂O₄: Eu : Gd was prepared with the conventional solid-state reaction method. Gd is sensitizer of Eu, there is energy transform between Gd and Eu. The main peak at 613 nm can be ascribed to ⁵D₀→⁷F₂ of Eu³⁺ . The luminescent intensity is improved.（4） The Zn_0．5 Sr_0．5 Ga₂O₄ : Eu prepared by solid-state method. The results of the experiment show that the produced powder is the mixture of ZnGa₂O₄ and SrGa₂O₄．更多还原