Free-standing graphene at atomic resolution

Abstract

Research interest in graphene, a two-dimensional crystal consisting of a single atomic plane of carbon atoms, has been driven by its extraordinary properties, including charge carriers that mimic ultra-relativistic elementary particles. Moreover, graphene exhibits ballistic electron transport on the submicrometre scale, even at room temperature, which has allowed the demonstration of graphene-based field-effect transistors and the observation of a room-temperature quantum Hall effect. Here we confirm the presence of free-standing, single-layer graphene with directly interpretable atomic-resolution imaging combined with the spatially resolved study of both the π → π* transition and the π + σ plasmon. We also present atomic-scale observations of the morphology of free-standing graphene and explore the role of microstructural peculiarities that affect the stability of the sheets. We also follow the evolution and interaction of point defects and suggest a mechanism by which they form ring defects.

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Figure 1: Thickness analysis of graphene layers.
Figure 2: High-resolution images of mono-layer graphene.
Figure 3: HAADF lattice images of defects.
Figure 4: Termination of hexagon rows in HAADF images.
Figure 5: Edge structures of graphene.

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Acknowledgements

The authors wish to thank the Engineering and Physical Sciences Research Council (EPSRC) for SuperSTEM funding under grant EP/D040396/1.

Author information

M.H.G., U.B., A.L.B. and A.K.G. conceived and designed the experiments. R.R.N. performed sample preparation. M.H.G., U.B. and A.L.B. carried out the experiments and performed data analysis. P.W. performed the image simulations. M.H.G., U.B. and A.L.B. co-wrote the paper. All authors discussed the results and commented on the manuscript.

Correspondence to Mhairi H. Gass.

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Gass, M., Bangert, U., Bleloch, A. et al. Free-standing graphene at atomic resolution. Nature Nanotech 3, 676–681 (2008). https://doi.org/10.1038/nnano.2008.280

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