半导体单晶-凝胶复合材料的研究

发布时间：2019-02-12 11:38

【摘要】：凝胶扩散法作为一种简单、高效、能在常温下进行并得到高质量晶体的晶体生长方法得到了广泛的应用。自1969年Nickl和Henisch发现凝胶会在生长过程中嵌入晶体以来,人们发现越来越多的凝胶会嵌入晶体形成单晶-凝胶复合材料。目前人们已制备出碳酸钙、蛋白质、氨基酸等单晶与琼脂、果胶、硅胶等凝胶的单晶复合材料,并证明了被凝胶三维网络贯穿的单晶复合结构,而且该复合结构保持单晶的长程有序特性。尽管目前这种具有特殊结构的单晶复合材料能够被成功制备,但是走向功能化和应用还有很长的一段路要走。而实现功能化可大致通过三方面来实现：在凝胶中制备具有功能性的单晶；采用功能性凝胶作为晶体生长介质；引入除晶体和凝胶外的具有功能性的第三组分。本论文将围绕第一种方法,通过在凝胶中制备半导体晶体,为实现单晶复合材料的功能化探索可能的方向。我们在硅胶、琼脂水凝胶介质中合成了硫化铅、碘化铅等半导体单晶,并形成单晶复合材料,证明了半导体单晶与凝胶网络形成复合材料的可能性。在本文第一章,我们首先介绍了单晶的特性与生长方法,并重点介绍了本文中所用的凝胶扩散法,单晶-凝胶复合材料的发现与结构特性,相应半导体复合材料的特性等。同时综述了近年来单晶复合材料的研究进展。在论文第二章,我们合成了立方晶系半导体PbS晶体与硅胶、琼脂的单晶复合材料,并表征了其形态及内部结构。并探究了不同胶浓度、温度、pH下单晶复合材料结构的差异。在第三章,我们探究了铅的卤化物PbI2和PbCl2晶体在硅胶和琼脂凝胶中的生长。我们发现晶体的形态结构对凝胶嵌入量会有明显的影响,同时以碘化铅为例说明了凝胶的嵌入可能会导致半导体带隙的变化。在论文第四章我们尝试合成了Cu20,并得到了Cu-Cu2O半导体-金属复合晶体与硅胶、琼脂的单晶复合材料的复合结构。在硅胶体系中我们得到了具有单晶外形但同时具有Cu-Cu2O核壳结构的复合晶体,并探究了在不同还原剂浓度下生长出晶体的不同。
[Abstract]:As a simple and efficient method, gel diffusion method has been widely used in the growth of high quality crystals at room temperature. Since Nickl and Henisch discovered that gel intercalates crystals in the growth process in 1969, it has been found that more and more gels are embedded into crystals to form monocrystalline gel composites. At present, single crystal composites of calcium carbonate, protein, amino acid and gel such as Agar, pectin and silica gel have been prepared. Moreover, the structure keeps the long-range order of single crystal. Although this single crystal composite with special structure can be successfully prepared at present, there is still a long way to go towards functionalization and application. Functionalization can be achieved in three ways: preparing functional single crystals in gel, using functional gels as crystal growth medium, and introducing functional third components except crystals and gels. This thesis will focus on the first method, through the preparation of semiconductor crystals in the gel, in order to achieve the functionalization of single crystal composites explore the possible direction. We have synthesized semiconductor single crystals such as lead sulfide and lead iodide in silica gel and Agar hydrogel medium and formed single crystal composite materials, which proves the possibility of forming composite material between semiconductor single crystal and gel network. In the first chapter, we first introduce the properties and growth methods of single crystals, and focus on the gel diffusion method, the discovery and structure characteristics of single-crystal gel composites, and the properties of semiconductor composites. The research progress of single crystal composites in recent years is also reviewed. In the second chapter, we synthesized the cubic semiconductor PbS crystal, silica gel and Agar single crystal composite, and characterized its morphology and internal structure. The structure differences of single crystal composites under different adhesive concentration, temperature and pH were investigated. In Chapter 3, we investigated the growth of lead halide PbI2 and PbCl2 crystals in silica gel and Agar gel. It is found that the crystal morphology has an obvious effect on the intercalation amount of the gel, and taking lead iodide as an example, it is shown that the intercalation of the gel may lead to the change of the band gap of the semiconductor. In chapter 4, we try to synthesize Cu20, and obtain the composite structure of Cu-Cu2O semiconductor-metal composite crystal with silica gel and Agar. In the silica gel system, we obtained the composite crystals with single crystal shape but also Cu-Cu2O core-shell structure, and investigated the different crystal growth under different reductant concentration.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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