Scanning tunneling spectroscopy of inhomogeneous electronic structure in monolayer and bilayer graphene on SiC
Scanning tunneling spectroscopy of inhomogeneous electronic structure in monolayer and bilayer graphene on SiC
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DOI：
10.1063/1.2771084
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发表时间：
2007-09-17
影响因子：
4
通讯作者：
Crommie, Michael F.
中科院分区：
文献类型：
--
作者：
Brar, Victor W.;Zhang, Yuanbo;Crommie, Michael F.
用扫描隧道谱(STS)研究了在碳化硅(0001)表面外延生长的单层和双层石墨烯的局域电子结构。低电压地形图像显示了精细的原子尺度的碳网络，而高偏置图像主要是紧急的空间不均匀的大尺度结构，类似于富碳重建的碳化硅(0001)。STS谱显示了单层和双层石墨烯/碳化硅在零偏压附近类似于100 meV的Gaplike特征，以及禁带边缘以上电子结构的显著空间不均匀。碳化硅/石墨烯界面的纳米结构与观察到的电子空间不均匀性相关。这些结果对于石墨烯/碳化硅中涉及电子输运或隧穿的潜在器件是相关的。(C)2007年美国物理研究所。
The authors present a scanning tunneling spectroscopy (STS) study of the local electronic structure of single and bilayer graphene grown epitaxially on a SiC(0001) surface. Low voltage topographic images reveal fine, atomic-scale carbon networks, whereas higher bias images are dominated by emergent spatially inhomogeneous large-scale structure similar to a carbon-rich reconstruction of SiC(0001). STS spectroscopy shows an similar to 100 meV gaplike feature around zero bias for both monolayer and bilayer graphene/SiC, as well as significant spatial inhomogeneity in electronic structure above the gap edge. Nanoscale structure at the SiC/graphene interface is seen to correlate with observed electronic spatial inhomogeneity. These results are relevant for potential devices involving electronic transport or tunneling in graphene/SiC. (c) 2007 American Institute of Physics.