拓扑缺陷对Armchair型小管径多壁碳纳米管输运性质的影响  

Effect of topological defects on transport properties of small diameter armchair multi- walled carbon nanotubes

作　　者：赵世奇[1] 吴建宝[1] 林琦[1] 何智强[1] 卢良志[1] 

机构地区：[1]上海工程技术大学基础教学学院,上海201620

出　　处：《原子与分子物理学报》2015年第3期414-420,共7页Journal of Atomic and Molecular Physics

基　　金：2013年国家级大学生创新创业训练计划项目(201310856033);2012年上海市大学生创新活动项目(cs1221001);2011年上海工程技术大学校基金(2011Q21)

摘　　要：采用密度泛函理论和非平衡格林函数方法研究了纯净的及带有不同数目的 Stone-Wale拓扑缺陷下的扶手椅型单壁,双壁和三壁小管径碳纳米管的能带结构和电子输运性质,通过计算并分析不同偏压下的微分电导和非弹性电子隧穿谱(IETS),计算结果表明单壁,双壁和三壁碳纳米管的特征偏压区间分别为[-1.0 V,1.0 V],[-0.5 V,0.5 V]和[-0.25 V,0.25 V],特征偏压区间内SW拓扑缺陷所产生的电导波动平缓,而特征偏压区间外因缺陷的数目变化所带来的电导波动显著,通过IETS谱线的分析得到单壁,双壁和三壁碳纳米管的特征峰偏压分别为±1.25 V,±0.625 V和±0.125 V.碳纳米管的特征偏压区间和IETS特征峰偏压可为较小管径碳纳米管单壁,双壁和多壁类型的区分提供一种新的途径,同时也为小管径多壁碳纳米管的输运性质在出现拓扑缺陷时的响应提供参考依据.Using the density-functional theory in combination with non-equilibrium Green’ s function technique, we studied the electronic band structure and transport of small diameter armchair single-walled, double-walled and triple-walled carbon nanotubes with different numbers of Stone-Wale topological defects （ SW） , by calculat-ing and analyzing the differential conductance under different bias and inelastic electron tunneling spectroscopy （ IETS） , the calculation results show that the characteristics of bias interval for small diameter single-walled, double-walled and three-walled CNTs are [-1.0V, 1.0V], [-0.5V, 0.5V] and [ -0.25V, 0.25V], re-spectively;Within the characteristics of bias interval, the fluctuation of differential conductance produced by SW defects are smoothness, while outside the characteristics of the biasing interval, the fluctuation of differential con-ductance volatile which introduced by the changing of SW defects’ number.By analyzing the IETS spectra, the bias of characteristic peaks for single-walled, double-walled and three-walled CNTs are ±1.25V, ±0.625V and ±0.125V, respectively.The characteristics of bias intervals and the bias of IETS peaks for single-walled carbon nanotubes, double-walled and multi-walled type of distinction provide a new way to distinguish small diameter different walled-type of CNTs, but also provide a reference for the response of the transport properties of small di-ameter multi-walled carbon nanotubes when topological defects occur.

关 键 词：拓扑缺陷 多壁碳纳米管 微分电导 非弹性电子隧穿谱 

分 类 号：O562[理学—原子与分子物理]