水热法制备纳米ZnO晶体及其发光性质研究

发布时间：2018-07-24 07:49

【摘要】： 近年来,信息技术应用发展迅猛,计算机等电子设备日新月异,新型光电材料作为其载体,受到科研工作者空前关注。纳米ZnO室温下带隙宽度3.37eV,激子束缚能60meV,在短波长发光器件、压电传感器、透明导电极、太阳能电池等领域广阔的应用前景。纳米ZnO形貌丰富,如量子点、纳米线、纳米棒、纳米管、纳米环以及量子阱等,随着结构的不同,纳米ZnO表现出许多优异的光电性能,因此,纳米ZnO可控生长具有重要意义。本文以获得不同形貌的纳米ZnO材料为出发点,以典型形貌的可控制备为重点,进一步研究其微观结构与宏观性质的关系。 首先,概述纳米ZnO材料的研究进展,简要介绍纳米ZnO材料的各种制备方法,比较各种方法之间的优缺点。重点介绍本小组采用低温水热法,在此基础上添加多种可溶性离子盐,制备不同形貌的纳米ZnO颗粒。以六水硝酸锌(Zn(N03)2·6H20)和六甲基四胺(C6H12N4)的混合水溶液为母液,添加多种可溶性离子盐(NaCl,、NaF,、KCl,、C6H5Na3O7、Na2SO4、K2SO4,、NiNO3Na2CH3COOH、Na2CO3等),控制反应温度和离子盐的浓度,分别得到六棱柱状、花状、球状、带状、片状等形貌纳米ZnO晶体。通过改变实验条件,研究离子盐种类、浓度、温度等制备工艺参数对形貌生长的影响。分析实验结果后得出结论：可溶性离子盐的引入,对纳米ZnO的形貌生长有重要影响,利用此方法有望实现纳米ZnO形貌的可控生长。 其次,纳米ZnO材料的光电性能与其生长过程和结晶质量有着密切的联系。利用多种表征手段对不同形貌的纳米ZnO材料进行结构分析,结合晶体结晶成核理论,分析样品生长机理和缺陷来源。通过测量各种形貌纳米ZnO的拉曼图谱,分析各个样品特征峰的强度,位置和峰位的移动,达到对其内部结构的认识。通过测量各种形貌纳米ZnO的光致发光谱,对发光峰的强度,位置和峰位的移动,结合发光理论,定性分析表明,晶体内的缺陷类型主要为氧空位,氧空位的浓度不同造成发光强度发生变化,同时,掺入的离子盐种类不同,缺陷的包裹环境不同,发光峰位出现移动。进一步的研究将解释发光性质与缺陷之间的关系。
[Abstract]:In recent years, with the rapid development of information technology and the rapid development of electronic equipment such as computers, new optoelectronic materials have been paid more and more attention by researchers. The band gap width of nanometer ZnO is 3.37 EV at room temperature, and the exciton binding energy is 60 MEV. It has a wide application prospect in the field of short-wavelength luminescent devices, piezoelectric sensors, transparent conductors, solar cells and so on. The morphology of nanocrystalline ZnO is abundant, such as quantum dots, nanowires, nanorods, nanotubes, nanometers and quantum wells, etc. With the different structures, nanocrystalline ZnO exhibits many excellent optoelectronic properties. Therefore, the controllable growth of nanocrystalline ZnO is of great significance. In this paper, the relationship between microstructure and macroscopical properties of nanosized ZnO materials with different morphologies is further studied by focusing on the controllable preparation of typical morphologies. Firstly, the research progress of nano ZnO materials is summarized, and the preparation methods of nano ZnO materials are briefly introduced, and the advantages and disadvantages of different methods are compared. This paper focuses on the preparation of ZnO nanoparticles with different morphologies by using low temperature hydrothermal method and adding various soluble ionic salts. The mixed aqueous solution of zinc nitrate hexahydrate (Zn (N03) 2 6H20) and hexamethyltetramine (C6H12N4) was used as the mother liquor. The hexagonal column, flower, globular, banded, hexagonal columnar, flower-shaped, globular, banded, hexagonal columnar, flower-like, globular, banded, and so on were obtained by controlling the reaction temperature and the concentration of ionic salt, respectively. Nanocrystalline ZnO crystals with flake morphology. By changing the experimental conditions, the effects of the kinds of ionic salts, the concentration and the temperature on the morphology growth were studied. After analyzing the experimental results, it is concluded that the introduction of soluble ionic salts has an important effect on the morphology growth of nanometer ZnO, and this method is expected to realize the controllable growth of nanometer ZnO morphology. Secondly, the optoelectronic properties of nanometer ZnO materials are closely related to their growth process and crystallization quality. The structure of nanocrystalline ZnO materials with different morphologies was analyzed by various characterization methods. The growth mechanism and defect source of the samples were analyzed based on the crystal crystallization nucleation theory. By measuring the Raman spectra of various morphologies of nanometer ZnO, the intensity, position and movement of the characteristic peaks of each sample were analyzed, so that the internal structure of the samples could be understood. By measuring the photoluminescence spectra of various morphologies of nanometer ZnO, the intensity, position and shift of the luminescence peaks are measured. Combined with the luminescence theory, the qualitative analysis shows that the defect types in the crystals are mainly oxygen vacancies. The concentration of oxygen vacancy causes the change of luminescence intensity, at the same time, different kinds of ion salts doped, the surrounding environment of defects are different, and the peak position of luminescence shift. Further research will explain the relationship between luminous properties and defects.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：TB383.1

【参考文献】

相关期刊论文 前2条

1 王久亮,刘宽,秦秀娟,邵光杰;纳米氧化锌的应用研究展望[J];哈尔滨工业大学学报;2004年02期

2 蔡连和;氧化锌在面砖釉料中的应用[J];陶瓷工程;1994年04期

，

本文编号：2140708