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锂硅酸盐长余辉发光材料的研究

时间:2020-10-16 17:17来源:毕业论文
以氢气为还原气氛,制备出一种黄色发光长余辉Li2SrSiO4:Eu2+,Nd3+材料和一种绿色发光长余辉Li2SrSiO4:Tb3+材料。采用荧光分光光度计测量了激发光谱、发射光谱;用射线衍射分析仪测定样品的

摘要发光性能稳定、亮度大、无放射性等是长余辉发光材料的优点,使其收到很高的关注度。实验运用了高温固相法在还原气氛氢气中合成了硅酸盐系的长余辉发光材料。

以氢气为还原气氛,制备出一种黄色发光长余辉Li2SrSiO4:Eu2+,Nd3+材料和一种绿色发光长余辉Li2SrSiO4:Tb3+材料。采用荧光分光光度计测量了激发光谱、发射光谱;用射线衍射分析仪测定样品的晶型结构;探索了稀土离子的掺杂比例与发光性能之间的关系,确定了性能较好的硅酸锶锂长余辉发光材料的比例。发射光谱检测得Tb3+离子的典型5D4-7Fj跃迁,相应于X =0.3161,Y =0.5472CIE色度坐标. 发射光谱为500-700nm的一个宽带发射,最高峰位于578nm对应于Eu2+的4f65d1-4f7的跃迁,对应x=0.5027, y=0.492 CIE色度坐标。Tb3+的在基质中最佳浓度确定为1%,Eu2+,Nd3+共掺杂的最佳浓度确定为1%和0.4%。当紫外线光源被关闭,Li2SrSiO4: Tb3+和Li2SrSiO4: Eu2+,Nd3+荧光粉呈典型的余辉的行为。在拟合实验数据后展现了一个典型的三重指数衰减行为。热释光的研究进一步表明,Li2SrSiO4:Tb3+荧光粉的余辉行为是由于价带产生的电子和稀土离子(Tb3+)掺杂Li2SrSiO4产生的空穴的复合产生的,Li2SrSiO4: Eu2+,Nd3+荧光粉的余辉性能优异是由于Nd3+离子的加入导致陷阱浓度的增大,从而增加余辉长度的。58125

毕业论文关键词:硅酸盐,长余辉,陷阱,光谱

The study of long afterglow materials of Li2SrSiO4

Abstract: In the recent years, rare earth luminescent materials attracted more interest due to their excellent properties such as stability, high-efficiency, high-brightness, no radiation, excellent repeatability and environmental capability. In this study, long lasting phosphorescence silicates were synthesized by solid state reaction.

A novel green emitting long afterglow phosphor Li2SrSiO4:Tb3+ and yellow emitting long afterglow phosphor Li2SrSiO4: Eu2+,Nd3+were obtained via a high temperature solid-state reaction under the reductive atmosphere. The photoluminescence spectra were recorded on F-4500, XRD patterns of the samples were measured by the X-ray powder diffraction analytical instrument. The relationship between contents of( Eu, Nd,)  rare earth and add-on quantity of cosolvent and luminescent properties have been studied, obtain a recipe used for good performance silicate  phosphor. Typical 5D4-7Fj transitions of Tb3+  ions were detected by PL spectra, corresponding to CIE chromaticity coordinates of X =0.3161,Y =0.5472. Typical 4f65d1 → 4f7 transitions of Eu2+ ions were detected by PL spectra, revealing a broad and intensive emission extending from 500 to 700nm with a peak at about 587nm, corresponding to CIE chromaticity coordinates of x = 0.5027, y = 0.492. An optimal concentration of Tb3+  in the substrate was determined as 1%. Optimal concentrations of Eu2+ and Nd3+ in the substrate were determined as 1% and 0.4%. The Li2SrSiO4:Tb3+ phosphors and the Li2SrSiO4:Eu2+,Nd3+ phosphors showed a typical afterglow behavior when the UV source was switched off. A typical triple exponential decay behavior was confirmed after fitting the experimental data. Thermal simulated luminescence study further indicated that the afterglow behavior of The Li2SrSiO4: Tb3+ phosphors was generated by the recombination of electrons with the holes resulted from the doping of rare-earth ions (Tb3+) in Li2SrSiO4 host, and the enhancement of afterglow property of Li2SrSiO4: Eu2+,Nd3+phosphors was due to the increasement of trap concentration resulting from the incorporation of Nd3+ ions, thereby improving afterglow time.

Key Words: Li2SrSiO4;Long afterglow; Traps.spectrum.

第一章 绪论 1

1.1引言 1

1.2长余辉发光材料的研究现状 锂硅酸盐长余辉发光材料的研究:http://www.lwfree.com/cailiao/lunwen_63081.html

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