Dependence of electronic properties of epitaxial few-layer graphene on the number of layers investigated by photoelectron emission microscopy
Dependence of electronic properties of epitaxial few-layer graphene on the number of layers investigated by photoelectron emission microscopy
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DOI：
10.1103/physrevb.79.125437
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发表时间：
2009-03-01
影响因子：
3.7
通讯作者：
Watanabe, Y.
中科院分区：
文献类型：
--
作者：
Hibino, H.;Kageshima, H.;Watanabe, Y.
我们用光电子能谱和低能电子显微镜研究了在6H-SiC(0001)衬底上外延生长的几层石墨烯的电子性质。利用二次电子(SE)和C1S光电子的光电子发射显微镜(PEEM)图像可以区分具有不同石墨烯层数的区域。SE发射光谱表明，功函数随石墨烯层数的增加而增大，少层石墨烯中的空态促进了SE发射。C1s PEEM图像表明，随着石墨烯层数的增加，C1s核能级向较低的结合能方向移动，这与已报道的Dirac点能量与厚度的关系一致。
We used spectroscopic photoemission and low-energy electron microscopy to investigate the electronic properties of epitaxial few-layer graphene grown on 6H-SiC(0001). Photoelectron emission microscopy (PEEM) images using secondary electrons (SEs) and C 1s photoelectrons can discriminate areas with different numbers of graphene layers. The SE emission spectra indicate that the work function increases with the number of graphene layers and that unoccupied states in the few-layer graphene promote SE emission. The C 1s PEEM images indicate that the C 1s core level shifts to lower binding energies as the number of graphene layers increases, which is consistent with the reported thickness dependence of the Dirac point energy.