硅碳纳米材料的电子输运及调控

发布时间：2018-01-08 04:12

本文关键词：硅碳纳米材料的电子输运及调控　出处：《山东大学》2017年博士论文　论文类型：学位论文

【摘要】：低维纳米电子器件的物理性能非常独特,近些年来受到了研究人员的高度关注。电子器件的低能耗、小型化、高敏感性以及高速度,是电子器件开发利用的发展趋势。由于具有有序结构的一维纳米结构(线、棒、管、纳米带)或一维半导体纳米阵列,有利于载流子定向传输,使电子和空穴的分离效率和传输效率大大提高,所以成为制备下一代纳米光电器件的基础材料。虽然人们对低维纳米电子器件的研究已经取得了巨大的成功,但是关于其性质研究和制作工艺等方面还有很多问题没有彻底解决,所以纳米电子器件的发展和应用都还需要大量的研究和改进。该论文主要利用分子动力学模拟和基于扩展休克尔理论的非平衡格林函数的计算方法,研究了扶手椅和之字型碳纳米管中封装硅纳米线及掺杂硅纳米线结构,揭示了碳纳米管中的超细硅纳米线的结构变化及掺杂对硅纳米线的电子输运性质的影响,证实了硅纳米线含有掺杂原子时具有场效应晶体管性质以及单向导通性,分析了掺杂原子的作用机理;对门电极电压的调控影响的研究,为制作超细纳米线电子器件提供了理论依据,对深入理解硅基低维纳米材料的电子输运机制有重要的理论意义。论文最后分析了水分子吸附石墨烯对石墨烯电导的影响,探讨了利用石墨烯探测水分子吸附性的可行性及原理,该结果对于设计石墨烯传感器具有重要的理论指导意义。本论文主要研究内容及结果如下:(1)研究了 6种扶手椅和之字型碳纳米管中封装Si纳米线结构的演变,计算并得到了其伏安曲线、电导随外加偏压变化曲线及其结构的态密度图,讨论了银、铜、金和铝掺杂Si纳米线结构的电子传输特性,分析了硅-银、硅-铜、硅-金和硅-铝合金纳米线的电导谱。发现随着碳纳米管半径的增加,纳米线的结构从单原子链转变成了螺旋形和多重共轴圆柱,Si纳米线的结构不会随着碳纳米管手性(从Armchair转换为Zigzag)的改变而发生变化;硅纳米线的结构在传输特性上起到了很重要的作用,在(11,11)碳纳米管中形成的纳米线具有最好的传导率;硅-银,硅-铜,硅-金,硅-铝合金纳米线的电导率降低了,即掺杂金属原子不会提高半导体纳米线的电导率。(2)对锗、氯、氮掺杂硅纳米线中的不同结构的电子性质进行了研究,理论分析了掺杂对纳米线电子器件电子输运性质的影响。发现当掺杂原子在硅纳米线中集聚时,表现出更为剧烈的负微分电阻效应;另外还发现掺杂硅纳米线的电流峰值受掺杂原子的种类的影响;掺杂原子的分布对纳米线电子器件的电流电压曲线影响很大。透射率谱很好地解释了在低的源漏电压下门电压对纳米线电子器件的调控作用,说明了门电极能够有效地控制器件的开关并对电流有很好的调控作用。(3)研究了石墨烯吸附水分子对石墨烯带隙、电导和电子输运性质的影响。结果发现:吸附水分子的石墨烯的电子输运性质与水分子有序度之间存在线性关系,利用该关系可以用来探测吸附在石墨烯表面的水分子的有序度;当水分子有序吸附在石墨烯表面时,该体系具有最低的电导,相反,没有吸附水分子的石墨烯表现出最高的电导。该发现对于设计石墨烯传感器具有重要的理论指导意义。本论文的研究对深入理解低维硅碳纳米材料中的电子输运性质具有重要意义,为研发超细硅碳纳米线晶体管、设计高性能分子器件及设计开发单原子层纳米器件提供了理论指导。
[Abstract]:The physical properties of low dimensional nano electronic devices is very unique, in recent years has been highly concerned by the researchers. Low power consumption, miniaturization of electronic devices, Gao Min emotional and high speed, is the development trend of electronic devices. Because of one-dimensional nano structure with ordered structure (line, rod, tube, or nanoribbons) one dimensional semiconductor nano array, is conducive to the carrier directional transmission efficiency and transmission efficiency, so that the separation of electrons and holes is greatly improved, so become the foundation material for the preparation of the next generation of nano optoelectronic devices. Although the study of low Wiener meters electronic devices has achieved great success, but the nature of the research and production process etc. there are a lot of problems not solved thoroughly, so the development and application of nano electronic devices will still need a lot of researches and improvements. This paper mainly using molecular dynamics simulation And based on the calculation method of the nonequilibrium Green function extended Huckel theory, study the silicon armchair and zigzag carbon nanotubes doped silicon nanowires and nanowire structure nano, electronic structure and doping changes revealed ultrafine silicon carbon nanotubes nanowires on silicon nanowires's transport properties. Confirmed that the silicon nanowires containing doping atom with field effect transistor properties and unidirectional conductivity, analyzes the mechanism of doping; regulation of affect electrode voltage, for the production of ultrafine nanowire electronic devices provides a theoretical basis for understanding, has an important theoretical significance for electronic Si based low dimensional nano materials the transport mechanism. Finally this paper analyzed the influence of water molecular adsorption on graphene graphene conductance, discusses the feasibility and principle of detecting water molecular adsorption using graphene, the results of In the design of graphene sensor has an important theoretical significance. The main research contents and results of this thesis are as follows: (1) the Si package 6 armchair and zigzag carbon nanotubes in the evolution of nano wire structure, calculation and get its I-V curve, the conductance state density curve with bias and structural change the discussion, silver, copper, gold and aluminum doped Si nano electronic transmission characteristics analysis of the silicon nanowires, silicon - silver, copper, gold and silicon - silicon nanowires Aluminum Alloy spectrum. It is found that with the increase of carbon nanotube radius, the structures of the nanowires from a single atom into helical chain the shape and structure of multiple coaxial cylinders, not Si nanowires with carbon nanotubes (chiral conversion from Armchair to Zigzag) changes; the structure of silicon nanowires plays a very important role in the transmission characteristics, in the form of carbon nanotubes (11,11) in Na Vermicelli has the best conductivity; silicon - silicon - copper, silver, gold silicon, silicon nanowires conductivity Aluminum Alloy reduced, which will not increase the conductivity of metal atom doped semiconductor nanowires. (2) of germanium chloride, the electronic properties of different structure of nitrogen doped silicon nanowires was studied in this paper the research, theoretical analysis of the doped transport properties of nano electronic devices on the line. When the electron doped atom in silicon nanowires were found, showed more severe negative differential resistance; it is also found that the effect of current peak doped silicon nanowires by doping the great influence of current and voltage; the distribution curve of doping atoms of nanowires electronic devices. Transmission spectrum is a good explanation of the leakage voltage regulation of gate voltage on nanowire electronic devices in low source, the gate electrode can effectively control the switch and the current device Good regulation. (3) study on the adsorption of water molecules on the bandgap of graphene graphene, conductivity and electron transport properties of graphene. The results showed that the adsorption of water molecules of the electronic transport properties of water molecules and there is a linear relationship between the degree of order, the relationship can be used to detect the degree of order the water molecules adsorbed on graphene surface; when the water molecular adsorption on graphene surface, the system has the lowest conductivity, on the contrary, graphene not adsorbed water molecules exhibit the highest conductivity. It has important theoretical significance for the design of graphene sensor. This paper has important significance low dimensional silicon carbon nano materials of electronic transport properties in deep understanding, for the development of ultrafine silicon carbon nanowire transistors, provides a theoretical guidance for the design of high performance molecular devices and design and development of a single atomic layer of nano devices.

【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TB383.1;TN303

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