论文总字数：27963字

摘 要

白光LED由于体积小，能量转化率高，寿命长等优点，成为照明领域最有潜力的器件。但是现在使用的红色荧光粉性能却不能和其他颜色的荧光粉相媲美，这限制了LED发展。因此目前急需研制出一种高效的红色荧光粉。

稀土离子的发光特性在很多领域都有应用，很多科学家都展开了对它的研究。其中稀土离子的发光除了与自身电子能级跃迁有关，还与基质的结构和性能有着很大的关系。因此，双钙钛矿材料在新型红光荧光材料中被大量研究。选择合适的双钙钛矿材料作为荧光基质，通过掺杂红光稀土离子Eu³ ，在合成出新型高效红色荧光粉具有一定的研究价值。

本文用高温固相法合成了Eu³ 掺杂的 La₂LiSbO₆双钙钛矿荧光粉，并采用了XRD、SEM及荧光光谱测试对荧光粉相组成、形貌及发光性能进行分析。结果表明，在反应温度为1200℃，保温时间为5h，得到的荧光粉为单斜双钙钛矿结构，发光强度最高，且最强激发峰处于紫外光波段，发射光谱由Eu³ 特征发射峰构成，最强发射峰位于615nm。进一步研究发现，随着Eu³ 的增加，发光强度先增大后减小，在掺杂浓度为0.36时达到最大。另外，引入少量的Bi³ 离子可以显著提高La_1.64LiSbO₆：0.36Eu³ 荧光粉的发光性能，Bi³ 离子掺杂浓度为0.01时达到最佳，发光强度相比Bi³ 离子未掺杂时提高了近46 %，显示出其在白光LED用红色荧光粉中具有良好的应用前景。

关键词：发光中心 荧光基质材料 敏化离子 固相合成

Abstract

White LEDs have turn into the most promising facility in the field of light due to their small volume, high energy effect and long-life. However, the performance of the red phosphor used now is not comparable to that of other colors, which limits the development of LED. So, finding an high intensity red phosphor will be immediate.

The luminescent properties of Ln³ ions have been used in extensive fields. Many scientists have begun to go into them. Among them, the luminescence of Ln³ ions are not only related to their own electronic gap but also the structure and the property. Double perovskite materials have been widely studied in new red fluorescent materials. It has certain study value in synthesizing novel efficient red phosphor, by doping Eu³ .

Eu³ doped La₂LiSbO₆ matrix was synthesized by high temperature solid phase synthesis in this paper, and the XRD, SEM and fluorescence properties of the phosphor were tested. The results show that the reaction temperature is 1200 ° C, the holding time is 5 h, the obtained phosphor is monoclinic double perovskite structure, the luminescence intensity is the highest, and the best excitation peak is in the ultraviolet band, and the strongest emission peak is located at 615 nm. And as Eu³ increases, the luminescence intensity did not increase all the time and reached a maximum at a doping concentration of 0.36. In addition, The introduction of a small amount of Bi³ ions can improve the luminescence properties of La_1.64LiSbO₆:0.36Eu³ phosphors, and the best concentration is 0.01. The luminescence intensity is improved by nearly 48% compared with that none of Bi³ ions, which shows that it has a good application prospect in red phosphors for white LEDs.

Key Words: Luminescent center; Fluorescence host material; Sensitizing ions; Solid phase synthesis

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1 研究背景 1

1.1.1 红色荧光粉的研究现状 1

1.1. 2 双钙钛矿的研究现状 3

1.2 稀土离子及荧光材料的制备方法介绍 4

1.3 本课题研究意义和内容 4

第二章 实验方法 6

2.1 实验原料 6

2.2 实验仪器设备 6

2.3 样品制备 7

第三章 La₂LiSbO₆:Eu³ 单掺杂荧光粉的合成与发光特性 8

3.1 引言 8

3.2 La₂LiSbO₆:Eu³ 荧光粉的合成工艺及光学性能 8

3.2.1 预反应原材料的混合物分析 8

3.2.2 反应温度对La₂LiSbO₆:Eu³ 荧光粉的相组成与发光性能影响 9

3.2.3 保温时间对La₂LiSbO₆:Eu³ 荧光粉的形貌和发光性能的影响 13

3.3 不同掺杂浓度La_2-x Eu_xLiSbO₆的晶体结构与发光性能 14

3.3.1 La_2-x Eu_xLiSbO₆荧光粉的相组成与晶体结构 14

3.3.2 La_2-x Eu_xLiSbO₆荧光粉的荧光性能 15

3.4 本章小结 18

第四章 La₂LiSbO₆:Eu³ ,Bi³ 共掺杂荧光粉的合成与发光特性 19

4.1 引言 19

4.2 La₂LiSbO₆:Eu³ ,Bi³ 荧光粉的相组成 19

4.2 La₂LiSbO₆:Eu³ ,Bi³ 荧光粉发光特性 20

4.3 本章小结 24

第五章 结论与展望 25

5.1 结论 25

5.2 展望 25

参考文献 26

致谢 28

第一章 绪论

请支付后下载全文，论文总字数：27963字