有机与金属纳米复合薄膜非线性导电及光学性质研究

发布时间：2018-11-18 13:38

【摘要】：近年来,由于纳米金属的物理和化学性质和大块物质的差异性,受到了诸多学科领域研究人员广泛研究。很多金属元素的易结晶性质,都导致在制备膜材料时,特别是薄膜厚度达到纳米数量级时,大多数情况下薄膜样品是由非晶颗粒、微晶颗粒堆砌而成。如果为了改善颗粒之间的导通性质或者增加电阻率,势必会在制备薄膜的过程中适当添加其他不导电材料,甚至添加一些功能性元素,来提升或者改善其物理化学性质。因此薄膜材料的电、光学性质必将与金属类型、粒径大小,薄膜厚度和配体物质类型,以及制备工艺等因素有关。本文探讨了金属纳米颗粒薄膜以及与有机小分子荧光材料纳米颗粒薄膜的电光学性质。本文采用低真空溅射方法制备出纳米金颗粒结构复合薄膜。通过调节金属薄膜厚度、是否退火以及复合物质的类型等方法来实现了溅射法制备纳米金粒子的荧光性质可调。通过样品的扫描电镜(SEM)和X射线衍射(XRD)实验表征图谱发现,在有复合物质存在时并且不进行退火,溅射时间越短,粒径尺寸越小,复合物质对金粒子颗粒聚集有控制作用。经过退火之后,粒径明显增加。拉曼散射光谱(RSS)图谱表征发现,纳米金与复合物质发生一定的反应,形成有特殊拉曼峰的新结构物质。UV-Vis实验结果表明不同条件下的复合薄膜对紫外吸收的能力有一定差别。我们从荧光发射光谱结果得到,荧光强度和效率与复合物质,是否退火以及厚度有关。SEM,I-V和荧光发射光谱等实验表征结果表明,通过真空蒸镀方法制备纳米铝薄膜中的铝是以颗粒形式存在,颗粒尺寸大约在30-60纳米之间,纳米颗粒之间的的间距约为1～10纳米。采用模拟计算得到伏安曲线和实验测到的结果趋势上基本吻合。实验中发现,当样品的厚度较薄的时候(30纳米以下)则表现出非线性电学特性,当厚度达到30纳米以上时则其性质和大块金属的曲线走向接近。纳米荧光发射光谱实验结果表明,纳米铝对有机物DPO的结构有一定影响,导致其荧光性质的发生一定的改变。
[Abstract]:In recent years, the physical and chemical properties of nano-metals and the differences of bulk materials have been widely studied by researchers in many disciplines. The easy crystallization properties of many metallic elements lead to the preparation of film materials, especially when the thickness of the film reaches nanometer order of magnitude. In most cases, the film samples are made up of amorphous particles and microcrystalline particles. In order to improve the conductivity between particles or increase the resistivity, other non-conductive materials and even some functional elements will be added in the process of preparing films to improve or improve their physical and chemical properties. Therefore, the electrical and optical properties of the thin film must be related to the metal type, particle size, film thickness and ligand material type, as well as the preparation process. In this paper, the electrooptical properties of metal nanocrystalline films and nanocrystalline films with organic small molecule fluorescent materials have been investigated. In this paper, nanocrystalline gold composite films were prepared by low vacuum sputtering. The fluorescence properties of gold nanoparticles prepared by sputtering were adjusted by adjusting the thickness of metal films, annealing or not, and the type of composite materials. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) spectra show that the smaller the sputtering time and the smaller the particle size, the shorter the sputtering time is and the smaller the particle size is when the composite material is present and not annealed. The composite material can control the aggregation of gold particles. After annealing, the particle size increases obviously. The (RSS) spectra of Raman scattering showed that the gold nanoparticles reacted with the composite materials to a certain extent. The UV-Vis results show that the UV absorption ability of the composite films is different under different conditions. We obtained from the fluorescence emission spectra that the fluorescence intensity and efficiency are related to the composition, annealing and thickness. The results of SEM,I-V and fluorescence emission spectra show that, The aluminum in nano-aluminum thin films is prepared by vacuum evaporation. The size of the particles is about 30-60 nm, and the spacing between the nanoparticles is about 110nm. The voltammetric curves obtained by simulation are in good agreement with the experimental results. It is found that when the thickness of the sample is thin (less than 30 nm), it shows nonlinear electrical properties, and when the thickness is above 30 nm, the property of the sample is close to the curve of the bulk metal. The results of nano-fluorescence emission spectra show that nano-aluminum has a certain influence on the structure of organic DPO, resulting in a certain change of its fluorescence properties.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2

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