边缘重构对锯齿型石墨烯纳米带电子输运的影响

摘要

Edge reconstructions of graphene nanoribbons and their stable defective configurations were identified by experi-mental characterization. First principles calculations are performed to evaluate the effects of atomic edge arrangement on the electronic transport properties of zigzag graphene nanoribbons. It is found that these two defective edge structures affect effectively the high stable nanostructure configuration and give rise to pronounced modifications on electronic bands, leading to the shift of Fermi level as well as the occurrence of resonant energies. Both of these two atomic recon-structions would limit the electron transport around the Fermi level, and result in the complete resonant backscattering taking place at different locations. The suppression of conductance is not only related with increasing defect size, but more sensitive to the distribution of defect state, and the modifications on the electronic bands that are influenced by the edge reconstructions.%实验研究表明石墨烯纳米带中广泛地存在边缘结构重构且稳定的边缘缺陷结构。本文采用第一性原理的计算方法研究了锯齿型石墨烯纳米带中边缘结构重构形成的两种不同缺陷结构对材料电子输运性能的影响。研究发现两种缺陷边缘结构对稳定纳米尺度位型结构和电子能带结构具有显著影响，它使得费米能级发生移动并引起了共振背散射。两种边缘缺陷重构均抑制了费米能级附近电子输运特性并导致不同区域的电子完全共振背散射，电导的抑制不仅与边缘缺陷结构的大小有关，它更取决于边缘缺陷重构位型引起的缺陷态的具体分布和电子能带的移动。