Nov 1, 2011
How to make graphene
Graphene is the ultrathin form of carbon that was first discovered at the University of Manchester in 2004. It is often dubbed "the wonder material" on account of its incredible properties, which promise many applications – from ultrafast transistors to DNA sequencing. For discovering graphene and for their pioneering studies of the material, Andre Geim and Konstantin Novoselov shared the 2010 the Nobel Prize for Physics.
In this special video report, Physics World reporter James Dacey visits Geim and Novoselev's laboratory at the University of Manchester to learn how graphene is created and why it is so special. To begin, Dacey meets researcher Branson Belle who demonstrates the famous "Scotch tape" method for isolating graphene. This surprisingly simple technique involves placing a sample of graphite onto sticky tape and then folding and peeling the tape several times to create progressively thinner layers of graphite – eventually leading to a single layer of carbon.
Dacey then meets another graphene researcher, Aravind Vijayaraghavan, who places the sample under an optical microscope to explain how single-layer graphene is identified among thicker bits of graphite. "One of the nice things about graphene is that even though it's a two-dimensional material – the thinnest material in the world – we don't need an electron microscope to see it," explains Vijayaraghavan. Instead, by transferring the graphene to a silicon-based substrate, it creates the correct contrast to be able to identify thin sheets of carbon with a standard optical microscope. "With a bit of practise, you can just look at the screen and say 'right, that's a single layer'," he said.
Vijayaraghavan goes on to talk about some of the remarkable properties of graphene. "Despite the fact that it's the thinnest material that you can technically make it's also the strongest material – as in if you tried to rip it apart it takes more force than anything else," he said. Vijayaraghavan also talks about some of the unusual electrical and optical properties. "The electrons in graphene behave as if they are particles of light – so they don't get scattered".
The interview closes with Vijayaraghavan speculating about how these properties could lead to possible applications including ultrafast transistors and flexible electronic screens.
About the author
James Dacey is a reporter for nanotechweb.org's sister website physicsworld.com