石墨烯中由分离的(1,0)位错形成的有序晶界的结构和电子性质。

Structural and electronic properties of an ordered grain boundary formed by separated (1,0) dislocations in graphene.

作者信息

Ma Chuanxu, Sun Haifeng, Du Hongjian, Wang Jufeng, Zhao Aidi, Li Qunxiang, Wang Bing, Hou J G

机构信息

Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.

出版信息

Nanoscale. 2015 Feb 21;7(7):3055-9. doi: 10.1039/c4nr06789d.

DOI:10.1039/c4nr06789d

PMID:25603956

Abstract

We present an investigation of the structural and electronic properties of an ordered grain boundary (GB) formed by separated pentagon-heptagon pairs in single-layer graphene/SiO2 using scanning tunneling microscopy/spectroscopy (STM/STS), coupled with density functional theory (DFT) calculations. It is observed that the pentagon-heptagon pairs, i.e., (1,0) dislocations, form a periodic quasi-one-dimensional chain. The (1,0) dislocations are separated by 8 transverse rows of carbon rings, with a period of ∼2.1 nm. The protruded feature of each dislocation shown in the STM images reflects its out-of-plane buckling structure, which is supported by the DFT simulations. The STS spectra recorded along the small-angle GB show obvious differential-conductance peaks, the positions of which qualitatively accord with the van Hove singularities from the DFT calculations.

摘要

我们使用扫描隧道显微镜/能谱（STM/STS）结合密度泛函理论（DFT）计算，对单层石墨烯/二氧化硅中由分离的五边形 - 七边形对形成的有序晶界（GB）的结构和电子性质进行了研究。观察到五边形 - 七边形对，即(1,0)位错，形成了周期性的准一维链。(1,0)位错由8排横向碳环隔开，周期约为2.1纳米。STM图像中显示的每个位错的突出特征反映了其面外弯曲结构，这得到了DFT模拟的支持。沿小角度晶界记录的STS谱显示出明显的微分电导峰，其位置与DFT计算得到的范霍夫奇点定性一致。