掺杂对碳纳米管导电性影响的理论研究

发布时间：2018-06-20 02:54

本文选题：碳纳米管 + 第一性原理　；参考：《华北理工大学》2017年硕士论文

【摘要】：由于独特的结构和优异的物理、化学、电学性质,碳纳米管被认为是制备高性能复合材料的理想增强体,其中Al基体和Cu基体碳纳米管复合材料具有耐腐蚀、低密度、易加工等特性,具有非常广阔的应用前景。研究表明,碳纳米管与Al和Cu浸润性差,影响了碳纳米管与Al和Cu接触界面的导电性。而掺杂能改善碳纳米管与金属接触界面的导电性。本文采用基于密度泛函理论的第一性原理模拟研究了掺Fe碳纳米管对Al原子的吸附,掺B(N)碳纳米管对Cu原子的吸附以及含缺陷碳纳米管对Al原子的吸附。目前,与B(N)掺杂相比碳纳米管掺Fe的研究很少,并且Fe与碳纳米管功函数接近,相互之间的导电性较好,因此特别研究了掺Fe对碳纳米管导电性的影响。此外,本文还对含缺陷碳纳米管的Al吸附特性进行了研究。吸附能、能带结构和电荷分布的计算结果表明:掺Fe后,Al与碳纳米管之间由物理吸附转变为化学吸附,并提高了碳纳米管与Al接触界面的导电性;掺N提高了Cu与碳纳米管之间的共价性键结合;掺B提高了Cu与碳纳米管之间的离子性键结合,并改善了碳纳米管与Cu接触界面的导电性。51DB缺陷空位处吸附Al原子时,吸附能增大近三倍,但电荷转移量没有提高;拓扑缺陷七元环中心处吸附Al原子时,吸附能增加60%,电荷转移量提高45%。因此,拓扑缺陷可以改善碳纳米管与Al接触界面导电性。
[Abstract]:Because of its unique structure and excellent physical, chemical and electrical properties, carbon nanotubes are considered to be ideal reinforcements for the preparation of high performance composites. The Al matrix and Cu matrix carbon nanotube composites have the characteristics of corrosion resistance, low density, easy processing and so on. It has a very broad application prospect. The study shows that carbon nanotubes are infiltrated with Al and Cu. Poor sex affects the conductivity of the carbon nanotube interface with Al and Cu. Doping can improve the conductivity of the interface between the carbon nanotubes and the metal. This paper uses the first principle based on the density functional theory to simulate the adsorption of Al atoms with Fe carbon nanotubes, the adsorption of B (N) carbon nanometers to the Cu atom and the defective carbon nanometers. At present, there are few studies on the adsorption of Al atoms. Compared with B (N) doping, there are few studies on the incorporation of Fe in carbon nanotubes, and Fe is close to the work function of carbon nanotubes, and the conductivity of each other is good. Therefore, the effect of Fe on the conductivity of carbon nanotubes is specially studied. In addition, the adsorption properties of the Al in the nanotube containing defects are also studied. The adsorption energy and the energy of the adsorption energy are also studied in this paper. The calculation results of the band structure and charge distribution show that after the doping of Fe, the physical adsorption between Al and carbon nanotubes is converted to chemical adsorption, and the conductivity of the interface between the carbon nanotubes and the Al is enhanced, and the covalent bond bonding between Cu and the carbon nanotubes is enhanced by doping N, and B is improved by the doping of the ionic bond between the Cu and the carbon nanotubes, and the improvement of the bonding between the ionic bond and the carbon nanotube is improved. The adsorption energy increases nearly three times, but the charge transfer amount does not increase, while the charge transfer amount is not increased by the adsorption of Al atoms at the.51DB defect space at the contact interface of the carbon nanotube and Cu. The adsorption energy increases by 60% and the charge transfer amount increases 45%. when the center of the topology defect seven ring is located at the center. Therefore, the electrical conductivity of the carbon nanotube and Al interface can be improved by the topological collapse.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11;TB383.1

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