| AVS 56th International Symposium & Exhibition | |
| Graphene Topical Conference | Monday Sessions |
| Session GR-MoM |
| Session: | Graphene and 2D Carbon Nanostructures |
| Presenter: | P.M. Albrecht, Brookhaven National Laboratory |
| Authors: | P.M. Albrecht, Brookhaven National Laboratory E.A. Sutter, Brookhaven National Laboratory P.W. Sutter, Brookhaven National Laboratory |
| Correspondent: | Click to Email |
Epitaxy on transition metal substrates is a promising approach for the large-scale synthesis of graphene for potential applications in microelectronics and sensing. In particular, the controlled layer-by-layer growth of graphene on Ru(0001) has been shown to result in macroscopic monocrystalline graphene domains with lateral sizes greater than 200 microns, perfect thickness uniformity, and very low defect density [1]. Whereas the first graphene layer interacts strongly with the Ru(0001) template, the second layer is essentially decoupled from the metallic support, thus preserving the atomic structure and exotic electronic properties of isolated single-layer graphene [2]. A viable route towards large-area, free-standing graphene would be to grow on polycrystalline transition-metal thin films rather than single crystals, followed by the dissolution of the metal template to detach the graphene and transfer it to another support. Two groups have recently demonstrated the growth of few-layer graphene on polycrystalline Ni films using this method [3, 4].
Here, we report a study of graphene growth on Ru thin films. The polycrystalline Ru template layers were deposited on SiO2 by magnetron sputtering in ultrahigh vacuum. We used in-situ annealing and scanning tunneling microscopy (STM) to study the recrystallization and grain growth of the Ru template, crucial to forming a starting surface suitable for the growth of macroscopic graphene domains. STM also provided a detailed understanding of the interaction of the growing graphene layer with Ru grains with different surface orientations, grain boundaries, as well as highly vicinal surfaces. Cross-sectional transmission electron microscopy (TEM) was used to directly image the graphene-metal interface for the first time. Our results provide a basis for the scalable synthesis of graphene on transition metal thin films.
[1] P. W. Sutter, J.-I. Flege, and E. A. Sutter, Nature Mater. 7, 406 (2008).
[2] E. Sutter, D. P. Acharya, J. T. Sadowski, and P. Sutter, Appl. Phys. Lett. 94, 133101 (2009).
[3] A. Reina et al., Nano Lett. 9, 30 (2009).
[4] K. S. Kim et al., Nature 457, 706 (2009).