Intrinsic and extrinsic corrugation of monolayer graphene deposited on SiO2
Intrinsic and extrinsic corrugation of monolayer graphene deposited on SiO2
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DOI：
10.1103/physrevlett.102.076102
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发表时间：
2009-02-20
影响因子：
8.6
通讯作者：
Morgenstern, M.
中科院分区：
文献类型：
--
作者：
Geringer, V.;Liebmann, M.;Morgenstern, M.
利用超高真空扫描隧道显微镜和原子力显微镜，研究了石墨烯剥离后在Si/SiO_2(300 Nm)表面的波纹。而在SiO_2上的波纹是长程的，相关长度约为25 nm，而一些石墨烯单层显示出额外的波纹，其择优波长约为15 nm。详细的分析表明，在石墨烯上也可以看到衬底的长程波纹，但幅度有所降低，从而得出了石墨烯部分自由悬浮在衬底的山丘之间的结论。因此，如果石墨烯沉积在二氧化硅上，先前在人工悬浮石墨烯上观察到的本征涟漪也可以存在。
Using scanning tunneling microscopy in an ultrahigh vacuum and atomic force microscopy, we investigate the corrugation of graphene flakes deposited by exfoliation on a Si/SiO2 (300 nm) surface. While the corrugation on SiO2 is long range with a correlation length of about 25 nm, some of the graphene monolayers exhibit an additional corrugation with a preferential wavelength of about 15 nm. A detailed analysis shows that the long-range corrugation of the substrate is also visible on graphene, but with a reduced amplitude, leading to the conclusion that the graphene is partly freely suspended between hills of the substrate. Thus, the intrinsic rippling observed previously on artificially suspended graphene can exist as well, if graphene is deposited on SiO2.