几种含氧酸盐固溶体发光材料的结构和发光性质探究

发布时间：2018-05-02 00:37

本文选题：发光材料 + 固溶体　；参考：《中国科学技术大学》2017年博士论文

【摘要】：作为常见的固态发光材料之一,稀土离子激活的发光材料如今已被广泛应用于白光LED、上转换发光、长余辉以及量子剪裁等领域。固溶体发光材料的出现为寻找新型功能材料提供了更丰富的素材,其结构性质在很大程度上决定了该材料的光、电、磁、热等性质。对固溶体材料结构组成的研究,并建立其结构组成和各方面应用性能之间的联系,因其对新型功能材料的开发具有指导意义而成为当今固态无机化学材料科学领域的重要研究方向之一。固溶体发光材料对发光材料的性能调控具有重要意义,其在稀土掺杂和过渡族金属离子掺杂发光材料中占据着越来越重要的地位。发光材料的结构性质在很大程度上决定了其发光性质,例如直接影响激发和发射光谱中峰型、峰值位置以及峰宽等,它们直接决定了该材料的性能和使用前景。这意味着深入研究发光材料结构性质和发光性质之间的联系显得尤为必要,它对开发新型发光材料具有十分重要的指导意义。因此,本论文的主要工作是通过建立与实验结果相符的理论模型来试图寻找材料结构性质和发光性质之间的联系,并为寻找性能更为优异的新型发光材料提供一定的理论依据。本文主要内容和研究成果如下:第一章是本文的绪论部分,主要介绍了固溶体发光材料性质探究的选题意义、研究背景和现状,并对稀土掺杂发光材料以及固溶体材料的基础知识、基本原理和基本研究手段做了简单介绍,主要包括稀土元素的分类、稀土的光谱理论、稀土发光材料的应用以及稀土光谱的表征手段。同时,介绍了固溶体材料的定义、形成、类型、性能、作用以及研究方法等基本知识。第二章主要介绍了自激活固溶体发光材料Ba2xSr1-2xV207的结构和发光性质。首先,我们通过高温固相法合成了不同固溶比例下的样品,并通过X射线衍射谱对材料的结构性质做了表征。XRD结果表明我们成功合成固溶体。此外,我们还测得了不同固溶比例下样品的激发和发射光谱。实验结果表明激发和发射峰的位置和峰宽均随固溶比例变化呈现非单调变化。通过展示与实验结果相符的位形坐标图,我们把这种非单调性归结于固溶导致的非均匀程度的增加。Ba(2+)和Sr(2+)的非均匀分布不仅造成能级组的非均匀增宽,还通过增大交换作用常数使得激发态自旋单态和三重态之间的能级组间隔增大。此外,当Sr的占比达到3/4时谱线峰值位置和半高宽均出现极值,这表明度量无序程度的标准在此处发生变化。第三章主要介绍了掺杂稀土离子的长余辉固溶体发光材料BaxSr1-xAl204:Eu~(2+)的结构和发光性质。与第二章工作类似,不同固溶比例下样品的合成同样通过高温固相法实现,而材料的结构性质同样通过X射线衍射谱表征。XRD结果在证明成功合成固溶体的同时显示了我们的材料中出现的结构相变,同时我们还通过第一性原理计算估计了相变点,其结果与XRD结果相符。对于特定的固溶区间,我们监测了不同固溶比例下样品的发射光谱,并发现了发射光谱峰值位置与固溶比例的非单调依赖关系。与第二章内容不同的是,这里涉及的发光中心是掺杂离子而非具有电荷迁移带的自激活基团,因而我们需要建立不同于第二章的理论模型来解释此实验中出现的现象。通过分析,我们发现这种反常的光谱现象与Eu~(2+)在不同固溶比例样品中占据两种Ba格位的不同倾向性有关。第四章主要介绍了掺杂稀土离子Eu~(2+)和过渡族金属离子Mn~(2+)的卤磷酸盐Ca5(PO4)3(F0.8Cl0.2)样品的发光性质。与前两章内容不同的是,前两章主要考虑阳离子取代形成的固溶体,而本章则考虑阴离子取代所形成的固溶体。本实验中,所有样品均由高温固相法合成,并由X射线衍射谱表征。XRD结果显示我们成功合成了固溶样品,同时说明一定占比Cl-的引入并不会对Ca5(PO4)3F原本的晶格结构造成较大影响。在此材料中,我们研究了 Eu~(2+)向Mn~(2+)的能量传递以及如何通过调节Eu~(2+)、Mn~(2+)的掺杂浓度来实现白光。第五章主要介绍了掺杂Tb~(3+)、Ho~(3+)两种稀土离子的磷酸盐材料YPO4的发光性质以及其应用于荧光温度探测的可行性。我们通过水热法合成该样品,并通过X射线衍射谱对其结构进行了表征。XRD结果显示成功合成所需晶相。在本章中,我们提出了一种与传统的基于热耦合能级的上转换荧光温度探测不同的测温机制,并通过YPO4:3.2%Tb~(3+),0.8%Ho~(3+)样品展示了其原理。此测温机制主要利用到Tb~(3+)的基态热耦合能级,而Ho~(3+)的掺入则作为参照。实验结果表明该材料具有较高的测温灵敏度,因而具有一定的实用价值;同时也说明我们的测温方案具有一定的可行性,能够为寻找具有较好性能的荧光温度探测材料提供帮助。最后一章对本论文的主要内容做了总结并对固溶体发光材料的应用前景做了展望。
[Abstract]:As one of the common solid state luminescent materials, rare earth ions activated luminescent materials have been widely used in the fields of white light LED, upconversion luminescence, long afterglow and quantum cutting. The appearance of solid solution luminescent materials provides more abundant material for finding new functional materials. The structure and properties of the materials determine the material to a great extent. The study of the structure composition of solid solution materials and the relationship between the structure and the application properties of the solid solution materials have been established. Because of their guiding significance for the development of new functional materials, it has become one of the most important research directions in the field of solid inorganic chemical materials science. The performance control of the material is of great significance. It occupies an increasingly important position in the rare earth doped and transition metal ion doped luminescent materials. The structure and properties of the luminescent materials determine their luminescence properties to a large extent, such as the direct influence of the peak type, peak position and peak width in the excitation and emission spectra. They are directly determined by them. It is very necessary to study the relationship between the structural properties and luminescent properties of the luminescent materials, which is of great significance to the development of new luminescent materials. Therefore, the main work of this paper is to try to find the material by establishing a theoretical model consistent with the results of the test. The relationship between the properties of the material structure and the luminescence properties and the theoretical basis for finding new luminescent materials with more excellent properties are provided. The main contents and research results of this paper are as follows: the first chapter is the introduction part of this article, which mainly introduces the significance of the selection of the properties of solid solution luminescent materials, the background and the present situation, and the rare earth. The basic knowledge, basic principles and basic research methods of doped luminescent materials and solid solution materials are briefly introduced, including the classification of rare earth elements, the spectral theory of rare earth, the application of rare earth luminescent materials and the characterization means of rare earth spectra. At the same time, the definition, formation, type, properties, function and effect of solid solution materials are introduced. The second chapter mainly introduces the structure and luminescence properties of the self activated solid solution luminescent material Ba2xSr1-2xV207. First, we synthesized the samples with different solid solution ratio by high temperature solid phase method and characterized the structure and properties of the material by the X ray diffraction spectrum. The results show that we have successfully synthesized the solid solution. In addition, we have also measured the excitation and emission spectra of the samples with different solid solution ratios. The experimental results show that the position and peak width of the excitation and emission peaks are not monotonically changed with the change of the solid solution ratio. By displaying the coordinate maps consistent with the experimental results, we attribute this non monotonicity to the nonuniformity caused by the solution of solid solution. Increasing the non-uniform distribution of.Ba (2+) and Sr (2+) not only causes the inhomogeneous broadening of the energy level group, but also increases the energy level interval between the excited state spin singlet and the three heavy state by increasing the exchange constant. In addition, the peak value of the peak position and the half width of the spectral line of the Sr is reached to 3/4, which indicates the standard of measuring the degree of disorder. The third chapter mainly introduces the structure and luminescence properties of the long afterglow solid solution luminescent material BaxSr1-xAl204:Eu~ (2+) doped with rare earth ions. Similar to the second chapter, the synthesis of samples under different solid solution ratios is also realized by high temperature solid phase method, and the structure and properties of the material are also characterized by X ray diffraction (.XR). The D results show that the successful synthesis of solid solution shows the structural phase transition in our material. At the same time, we have estimated the phase transition point by the first principle. The results are in agreement with the XRD results. For a specific solution interval, we monitored the emission spectra of the samples with different solid solution ratios and found the emission spectrum peak. The non monotonic dependence of the position of the value on the solid solution ratio. Unlike the second chapter, the luminescent center involved is the doping ion rather than the self activating group with the charge transfer band, so we need to establish a theoretical model different from the second chapter to explain the phenomenon in this experiment. The spectral phenomena are related to the different tendencies of the Eu~ (2+) Eu~ (Ba) in different solid solution ratios. The fourth chapter mainly introduces the luminescence properties of the halophosphate Ca5 (PO4) 3 (F0.8Cl0.2) samples doped with the rare earth ions Eu~ (2+) and the transition metal ions Mn~ (2+). Unlike the previous two chapters, the first two chapters mainly consider cations. Instead of the solid solution formed, Moto Akinori considered the solid solution formed by the substitution of anions. In this experiment, all the samples were synthesized by the high temperature solid state method, and the results of the X ray diffraction spectrum showed that we have successfully synthesized the solid solution samples, and that the introduction of a certain proportion of Cl- does not cause the lattice structure of the original Ca5 (PO4) 3F to be more than that of the Ca5 (PO4) 3F. In this material, we have studied the energy transfer of Eu~ (2+) to Mn~ (2+) and how to achieve white light by adjusting the doping concentration of Eu~ (2+), Mn~ (2+). The fifth chapter mainly introduces the luminescence properties of the phosphate materials doped Tb~ (3+), Ho~ (3+) and two kinds of rare earth ions, and the feasibility of its application to the detection of fluorescence temperature. The sample was synthesized by hydrothermal method, and its structure was characterized by X ray diffraction..XRD results showed that the crystalline phase was successfully synthesized. In this chapter, we proposed a different temperature measurement mechanism which is different from the conventional upconversion temperature detection based on the thermal coupling energy level, and through YPO4:3.2%Tb~ (3+), 0.8%Ho~ (3+) samples are displayed. Principle. The temperature measurement mechanism is mainly used in the ground state thermal coupling energy level of Tb~ (3+), and the incorporation of Ho~ (3+) is used as reference. The experimental results show that the material has a high sensitivity of temperature measurement and therefore has a certain practical value. It also shows that our temperature measurement scheme has a definite feasibility for finding good performance of the fluorescence. Temperature detection materials provide help. In the last chapter, the main contents of this paper are summarized and the application prospects of solid solution luminescent materials are prospected.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O482.31

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