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采用密度泛函数的B3LYP和非平衡格林函数方法分别对锯齿型单壁(5.0)碳纳米管(SWCNT)及外接Au电极后的电子结构和电子传输特性进行了理论研究。另外用同样的方法,对弯曲的SWCNT和外接Au电极的器件的电子结构、电子传输特性进行了研究。比较发现,两个模型在HOMO状态下的电子分布主要集中在两端,总的传输性能比LUMO状态下要弱。虽然两种模型具有相似的能带结构,但弯曲SWCNT的能隙较未弯曲SWCNT的能隙要小。另外两种模型的传输谱与态密度有着明显的对应性,但弯曲的碳纳米管的传输谱较未弯曲碳纳米管的传输谱峰值大很多,说明弯曲过后SWCNT的电子输运性能要远优于未弯曲SWCNT。
The electron structure and electron transport properties of zigzag single-walled (5.0) carbon nanotubes (SWCNTs) and Au electrodes were investigated by using the B3LYP and unbalanced Green’s function methods of density functional theory. In addition, the electronic structure and electron transport properties of SWCNTs and Au electrodes attached were studied in the same way. It is found that the electronic distribution of the two models in the HOMO state is mainly concentrated on both ends, and the total transmission performance is weaker than that in the LUMO state. Although the two models have similar band structures, the energy gap of the curved SWCNTs is smaller than that of the unwound SWCNTs. The other two models have a clear correspondence between the transmission spectra and the density of states, but the transmission spectrum of the curved carbon nanotubes is much larger than that of the unbent carbon nanotubes, which shows that the electron transport properties of the SWCNTs are far better after bending Unbent SWCNT.