Periodically Modulated Electronic Properties of the Epitaxial Monolayer Graphene on Ru(0001)
Periodically Modulated Electronic Properties of the Epitaxial Monolayer Graphene on Ru(0001)
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Ru(0001) 上外延单层石墨烯的周期调制电子特性
DOI：
10.1021/jp2082962
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发表时间：
2011-12-22
影响因子：
3.7
通讯作者：
Zhao, Aidi
中科院分区：
文献类型：
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作者：
Feng, Wei;Lei, Shulai;Zhao, Aidi
利用扫描隧道显微镜/光谱（STM/STS）和第一性原理计算研究了Ru（0001）表面单层石墨烯（MG）的局域结构和电子性质.高分辨率的STM图像和STS光谱测量在一个大的偏置电压范围内表明几何和电子的MG。根据实验得到的dz/dV和I-z曲线，分别用两种方法得到MG/Ru（0001）表面的局域功函数（LWF）约为3.5eV。我们还发现了一个相当大的LWF差异（约100至200毫电子伏）之间的MG/Ru（0001）的莫尔图案的晶胞内的不同地点。此外，观察到明显的偏置极性依赖性的局部势垒高度（LBH）的MG在Ru（0001）表面上，支持的Smoluchowski平滑效应的存在，由于存在的表面偶极矩的结果，强大的MG-Ru相互作用。这些结果表明，MG/Ru（0001）可用作催化剂。
The local structural and electronic properties of the epitaxial monolayer graphene (MG) on Ru(0001) surface were investigated by using scanning tunneling microscopy/spectroscopy (STM/STS) and first-principles calculations. High resolution STM images and STS spectra measured in a large bias voltage range indicated both geometric and electronic corrugation of the MG. The local work function (LWF) of the MG/Ru(0001) surface was obtained to be around 3.5 eV by two separate methods based on the experimental dz/dV and I–z curves respectively. We also found a considerable LWF difference (about 100 to 200 meV) between different sites within a unit cell of the moire pattern of MG/Ru(0001). Furthermore, noticeable bias-polarity-dependence of the local barrier height (LBH) of MG on Ru(0001) surface was observed, supporting the existence of the Smoluchowski smoothing effect due to the presence of surface dipole moment in consequence of strong MG–Ru interactions. These findings indicate that MG/Ru(0001) can be used as...