论文总字数：26763字

摘 要

发光二极管（LED）不仅性能十分优异，而且节能、环保、装配紧凑、无汞并且使用寿命长，受到了极大的关注，在固态照明（SSL）邻域具有很大的应用前景。目前，白光LED多采用蓝光LED激发黄色荧光粉，但因热影响而使得发光效率下降、降低了LED器件的服役时间。而紫外转换法发光效率高、工艺简单，是商业化推广的重点也是研究的热点，但是目前亟待解决的是红色荧光粉的发光强度较弱的问题。

本论文以BaLaMgNbO₆作为基质，以Eu³ 为激活剂，通过高温固相法合成了一种红色荧光粉。通过X-射线衍射仪、透射电子显微镜的分析来探究荧光粉的相组成、晶体结构等。在此基础上,通过对Eu³ 掺杂量不同的荧光粉样品的激发光谱、发射光谱、紫外漫反射光谱进行分析，得出了猝灭浓度的实验值，并采用Ozawa和Dexter的理论计算理论猝灭浓度并确定浓度猝灭机理。并对不同Eu³ 掺杂量的荧光粉样品的红橙比和色坐标进行分析，得到Eu³ 的最佳掺杂量。此外，还对荧光粉的温度猝灭机理进行了研究。

关键词：LED 双钙钛矿 高温固相法 红色荧光粉

Preparation and Properties of BaLaMgNbO₆:Eu³ Red Phosphor

Abstract

Light-emitting diodes (LEDs) not only have excellent performance, but also are energy-saving, environmentally friendly, compact in assembly, mercury-free, and have a long service life. They have great prospects in solid-state lighting (SSL). At present, white LEDs produced in large quantities mostly take blue LEDs with yellow fluorescent powder together. However, such white LEDs will reduce the luminous efficiency and reduce the service time of LED devices due to thermal influence. The ultraviolet conversion method has high luminous efficiency and simple process. The ultraviolet conversion method uses ultraviolet, near-ultraviolet or blue-light LEDs to excite the red/green/blue trichromatic phosphors, thereby producing white light, which is the focus of commercialization because of its low cost, high luminous efficiency, and simple process. Though a hot spot, but what needs to be solved urgently is the problem of weak luminous intensity of red phosphors.

In this paper, BaLaMgNbO₆ was used as the matrix and Eu³ was used as the activator to synthesize BaLaMgNbO₆: Eu³ red phosphor by high temperature solid phase method. The phase composition, crystal structure, and some other characteristics of the phosphor were investigated by analysis with the X-ray diffractometer and the transmission electron microscope. On the basis of this, the experimental values were obtained by excitation spectrum, emission spectrum and ultraviolet diffuse reflectance spectrum of the phosphor samples with different Eu³ doping values, and the theoretical calculation theory of Ozawa and Dexter was used. The emission intensity ratio and color coordinates of different Eu³ doped phosphor samples were analyzed to obtain the optimal doping amount of Eu³ . In addition, the way of temperature quenching of the phosphor was also studied.

Key Words: LED; Double perovskite; High temperature solid phase method; Red phosphor

目录

摘 要 I

Abstract II

第一章 文献综述 1

1.1引言 1

1.2 发光二极管及白光发射方案 1

1.2.1发光二极管的组成 1

1.2.2 白光LED的发光方案 2

1.3 荧光粉的发光原理 3

1.3.1 光致发光机理 3

1.3.2 稀土离子的能级跃迁及发光特点 5

1.3.3 稀土元素的发光猝灭 5

1.4 双钙钛矿红色荧光粉的研究进展 6

1.5 荧光粉的制备方法 7

1.5.1 高温固相法 7

1.5.2 溶胶-凝胶法 8

1.5.3 化学共沉淀法 9

1.6 论文研究的内容和意义 10

第二章 实验与测试方法 11

2.1 主要原料和试剂 11

2.2 主要实验仪器和测试设备 11

2.3 样品制备 11

2.4 主要的分析方法 12

2.4.1 X-射线衍射仪 12

2.4.2 透射电子显微镜 12

2.4.3 荧光分光光度计 12

2.4.4 紫外-可见分光光度计 13

第三章 发光性能以及浓度猝灭的研究 14

3.1 引言 14

3.2 Eu³ 掺杂量的变化对于荧光粉结构和光学性能的影响 14

3.2.1荧光粉的相组成及结构特征 14

3.2.2 Eu³ 掺杂量不同的BaLaMgNbO₆:Eu³ 荧光粉的光学性能 17

3.3 BaLaMgNbO₆:Eu³ 荧光粉的浓度猝灭 21

3.4 BaLaMgNbO₆:Eu³ 荧光粉的温度猝灭 23

第四章 结论 26

参考文献 27

致谢 29

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