标题:
扶手椅型碳纳米管在不同片层下的电子输运性质的研究
The Research on the Electric Transport Properties of
Armchair Carbon-Nanotubes Composed by Different Layers of Graphite Sheet
作者:
赵世奇, 吴建宝, 何智强, 卢良志
关键字:
碳纳米管, 电子输运, 微分电导
Carbon Nanotube; Electric Transport Properties; Differential Conductance
期刊名称:
《Applied Physics》, Vol.3 No.4, 2013-06-24
摘要:
本文采用密度泛函理论和非平衡格林函数方法研究了扶手椅型不同片层(单壁、双壁和三壁)碳纳米管的能带结构和电子输运性质，计算结果表明单壁碳纳米管的微分电导在[−1.0 V，1.0 V]偏压区间内是一定值，不随偏压的变化而变化。双壁碳纳米管CNT(3,3)@CNT(6,6)的带隙为0.55 eV，在偏压区间[−0.5 V，0.5 V]的微分电导为零，出现与二极管类似的截止状态，当偏压大于0.5 V时，微分电导也随之增大。三壁碳纳米管由于层间耦合作用以及体系增大所带来费米能级附近的电子态增多，三壁管的微分电导要比相同偏压下单壁和双壁管的微分电导大；同时由于相邻管间的快速振动，三壁碳纳米管的微分电导出现较大的震荡。单壁、双壁和三壁碳纳米管的电子输运特性的研究能够为不同片层的纳米管在纳电子器件方面的潜在应用提供可能。By performing first-principles calculations and non-equilibrium Green’s function, the energy band structure, transmission spectrum and current-voltage characteristics of armchair carbon-nanotube (Arm-CNT) composed by different layers graphite sheet are investigated. The calculation results show differential conductance of single-walled CNT is a certain value on within the [−1.0 V, 1.0 V] bias range, while the double-walled CNT(3,3)@CNT(6,6) has a band- gap of 0.55 eV, the differential conductance is zero within the [−0.5 V, 0.5 V] bias range, which appears similar to the cut-off state of the diode. When the bias voltage of double-walled CNT(3,3)@CNT(6,6) is greater than 0.5 V, the differential conductance increases. Due to interlayer coupling effects and the system increasing brought an increase of the electronic states near the Fermi level, the differential conductance of three-walled CNT is bigger than the single-walled and double-walled CNT at the same bias. At the same time, because of the rapid vibration between adjacent tubes, the differential conductance of three-walled CNT behaves larger shocks. The research on the electronic transport properties of single-walled, double-walled and triple-walled CNT provides more choices for potential application in the nano- electronic devices.