Sep 8 2014
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Image Credits: Kostsov/shutterstock.com
Since its discovery in 2004, graphene has been used in a wide range of applications and regarded by scientists as a wonder material. Graphene is a flat monolayer of carbon atoms compactly packed into a two-dimensional (2D) honeycomb network. This 2D material is the thinnest and strongest material known to man. It is known for its exceptional heat and electric conduction, high crystal and electronic quality, stretchability and almost transparent appearance.
Researchers are looking for ways to grow graphene on alternative materials using a variety of processes. Generally, graphene is grown at high temperatures on a metal surface by decomposing hydrocarbons in a catalytic manner. However, this method was found to be unsuitable for silver substrates, as these substrates were chemically inert and had low melting point.
Growing Graphene on Silver
Recently, researchers from Northwestern University and Argonne National Laboratory showed that graphene could be grown on a single-crystal silver substrate. The research was funded by the Department of Energy SISGR grant, Department of Energy Office of Science and the National Science Foundation.
They were able to grow graphene in an ultra-clean vacuum environment by using a graphite carbon source, which was deposited directly onto the silver substrate. The growth was possible without the need of a chemically active surface, and at low temperatures. Distinctive wave-like electron dispersion was noticed at the edges of the newly grown graphene.
The researchers also observed another interesting fact while growing graphene on silver. The graphene was electronically decoupled from the silver substrate, thereby allowing the fundamental properties of graphene to be easily studied and exploited instantly on the substrate. This was a new characteristic that was not observed when graphene was grown on other metals.
The graphene produced in this manner was atomically pristine, and can be successfully applied in many advanced technologies.
Applications
The following are the probable applications enabled by the above mentioned research:
- Interfacing of graphene with other 2D materials
- Ultra fast electronics
- Advanced optics
Conclusion
The breakthrough in growing graphene on silver is likely to enable researchers to explore graphene interfaces in the coming years with a new 2-D material such as silicene, which is entirely grown on silver.
Sources and Further Reading