Department of Physics, Purdue University, West Lafayette, Indiana 47907, United States.
Nano Lett. 2011 Sep 14;11(9):3663-8. doi: 10.1021/nl201590f. Epub 2011 Aug 16.
We report an atomically resolved scanning tunneling microscopy investigation of the edges of graphene grains synthesized on Cu foils by chemical vapor deposition. Most of the edges are macroscopically parallel to the zigzag directions of graphene lattice. These edges have microscopic roughness that is found to also follow zigzag directions at atomic scale, displaying many ∼120° turns. A prominent standing wave pattern with periodicity ∼3a/4 (a being the graphene lattice constant) is observed near a rare-occurring armchair-oriented edge. Observed features of this wave pattern are consistent with the electronic intervalley backscattering predicted to occur at armchair edges but not at zigzag edges.
我们报告了原子分辨扫描隧道显微镜对通过化学气相沉积在 Cu 箔上合成的石墨烯颗粒边缘的研究。大多数边缘在宏观上平行于石墨烯晶格的锯齿方向。这些边缘具有微观粗糙度，在原子尺度上也被发现遵循锯齿方向，显示出许多 ∼120°的转弯。在罕见的扶手椅取向边缘附近观察到具有周期性 ∼3a/4（a 是石墨烯晶格常数）的突出驻波模式。这种波模式的观察特征与预测在扶手椅边缘而不是锯齿边缘发生的电子谷间背散射一致。
