石墨烯纳米带电子输运器件结构的设计与性能研究
发布时间：2019-03-09 18:23
【摘要】：近几年,随着硅基电子器件的逐步微型化和微电子技术的迅速发展,分子器件已经成为未来电子器件发展的重要研究对象。而石墨烯的出现为纳米电子器件的发展带来了新的契机,由于石墨烯相对传统的硅基纳米材料具有更加优秀的电子学性能,所以石墨烯纳米带电子器件很有可能替代传统的硅基电子器件。随着众多领域的研究者们对石墨烯的关注,最近几年研究者们更加注重石墨烯分子器件的研究。许多实验和理论上研究它较多的是将石墨烯进行裁剪和掺杂,使其形成特殊的几何结构,从而表现出具有特殊性能的电子器件。因此本文通过裁剪石墨烯纳米带来设计不同几何形状的纳米器件,并利用第一性原理模拟计算纳米器件的电子结构并研究电子器件的输运性能。本文采用基于第一性原理的密度泛函理论结合非平衡格林函数的方法以扶手型双三角石墨烯纳米带为研究对象,以扶手型石墨烯作为电极,分别进行B(N)掺杂和BN共掺杂的研究,主要研究掺杂对扶手型双三角石墨烯纳米带器件输运性能的影响以及非对称掺杂对扶手型双三角石墨烯纳米带器件整流行为的影响。并且研究了以锯齿型石墨烯作为电极,分别进行B(N)掺杂和BN共掺杂锯齿型双三角石墨烯纳米带器件所引起的整流效应。对以扶手型石墨烯作为电极,以扶手型双三角石墨烯纳米带为研究对象,分别进行B(N)掺杂和BN共掺杂的研究,结果发现,单个硼或氮原子取代扶手型双三角石墨烯纳米带顶点的碳原子后,增强了体系的电导能力,并且出现了新颖的整流效应。分析表明:这是由于硼氮掺杂扶手型双三角石墨烯纳米带器件在正负偏压下分子能级的移动方向和前线分子轨道空间分布的不对称而产生的。最重要的是,当左右三角石墨烯纳米带的顶端原子同时被硼和氮掺杂后,体系的整流效应显著增强。对以锯齿型石墨烯作为电极,以锯齿型双三角石墨烯纳米带为研究对象,分别进行B(N)掺杂和BN共掺杂的研究,结果表明,硼氮掺杂后增强了体系的电导能力,出现了不同方向的整流行为,而且出现了负微分电阻效应。研究表明掺杂原子种类以及掺杂的位置影响着整流效应的方向。
[Abstract]:In recent years, with the gradual miniaturization of silicon-based electronic devices and the rapid development of microelectronics technology, molecular devices have become an important research object for the future development of electronic devices. The appearance of graphene brings a new opportunity for the development of nano-electronic devices, because graphene has better electronic properties than traditional silicon-based nanomaterials. Therefore, graphene nanoband electronic devices are likely to replace the traditional silicon-based electronic devices. In recent years, more and more attention has been paid to graphene molecular devices by researchers in many fields. Many experiments and theoretical studies have shown that graphene is cut and doped to form a special geometric structure, thus showing a special performance of electronic devices. In this paper, we design nano-devices with different geometric shapes by cutting graphene nanometres, simulate the electronic structures of nano-devices and study the transport properties of electronic devices by first-principles simulation. In this paper, the first-principles density functional theory combined with non-equilibrium Green's function method is used to study the double triangle graphene nanobelope, and the armrests graphene is used as the electrode. The effects of B (N) doping and BN co-doping on transport properties of hand-mounted double triangle graphene nano-band devices and asymmetric doping on rectifying behavior of hand-mounted double triangle graphene nano-band devices were studied respectively. The rectifying effect of B (N)-doped and BN-co-doped sawtooth double triangular graphene nanoband devices with sawtooth graphene as electrode was also studied. Using armchair graphene as electrode and double triangle graphene nanobelope as research object, B (N) doping and BN co-doping were studied respectively. When a single boron or nitrogen atom replaces the carbon atom at the apex of the double triangle graphene nanoband, the conductivity of the system is enhanced and a novel rectifying effect appears. The analysis shows that this is due to the asymmetric distribution of molecular energy levels and frontier molecular orbitals under positive and negative bias in boron-nitrogen-doped double trigonometric graphene nanoribbons. Most importantly, when the top atoms of the left and right triangular graphene nanobands are doped with both boron and nitrogen, the rectifying effect of the system is significantly enhanced. Using sawtooth graphene as electrode and zigzag double triangle graphene nano-band as research object, B (N) doping and BN co-doping were carried out respectively. The results showed that boron-nitrogen doping enhanced the conductivity of the system. The rectifying behavior appeared in different directions, and the negative differential resistance effect appeared. The results show that the type of doped atoms and the position of doping influence the direction of rectifying effect.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O613.71;TB383.1
本文编号：2437741
[Abstract]:In recent years, with the gradual miniaturization of silicon-based electronic devices and the rapid development of microelectronics technology, molecular devices have become an important research object for the future development of electronic devices. The appearance of graphene brings a new opportunity for the development of nano-electronic devices, because graphene has better electronic properties than traditional silicon-based nanomaterials. Therefore, graphene nanoband electronic devices are likely to replace the traditional silicon-based electronic devices. In recent years, more and more attention has been paid to graphene molecular devices by researchers in many fields. Many experiments and theoretical studies have shown that graphene is cut and doped to form a special geometric structure, thus showing a special performance of electronic devices. In this paper, we design nano-devices with different geometric shapes by cutting graphene nanometres, simulate the electronic structures of nano-devices and study the transport properties of electronic devices by first-principles simulation. In this paper, the first-principles density functional theory combined with non-equilibrium Green's function method is used to study the double triangle graphene nanobelope, and the armrests graphene is used as the electrode. The effects of B (N) doping and BN co-doping on transport properties of hand-mounted double triangle graphene nano-band devices and asymmetric doping on rectifying behavior of hand-mounted double triangle graphene nano-band devices were studied respectively. The rectifying effect of B (N)-doped and BN-co-doped sawtooth double triangular graphene nanoband devices with sawtooth graphene as electrode was also studied. Using armchair graphene as electrode and double triangle graphene nanobelope as research object, B (N) doping and BN co-doping were studied respectively. When a single boron or nitrogen atom replaces the carbon atom at the apex of the double triangle graphene nanoband, the conductivity of the system is enhanced and a novel rectifying effect appears. The analysis shows that this is due to the asymmetric distribution of molecular energy levels and frontier molecular orbitals under positive and negative bias in boron-nitrogen-doped double trigonometric graphene nanoribbons. Most importantly, when the top atoms of the left and right triangular graphene nanobands are doped with both boron and nitrogen, the rectifying effect of the system is significantly enhanced. Using sawtooth graphene as electrode and zigzag double triangle graphene nano-band as research object, B (N) doping and BN co-doping were carried out respectively. The results showed that boron-nitrogen doping enhanced the conductivity of the system. The rectifying behavior appeared in different directions, and the negative differential resistance effect appeared. The results show that the type of doped atoms and the position of doping influence the direction of rectifying effect.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O613.71;TB383.1
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