Graphene gets ready for the big time.

TLDR: Graphene’s uniformity and flatness make it easier to combine with current silicon technology, and many researchers who once worked on nanotubes are now focusing instead on graphene, which has properties that make it alluring for certain applications.

Abstract: Physicists are in the grips of graphene madness. At last week’s American Physical Society meeting in Pittsburgh, Pennsylvania, they packed conference rooms to hear about the atom-thick sheets of honeycombed carbon. Talks on graphene transistors, chemical sensors, electrodes, scales and frequency generators could all be heard, with participants from industry, notably IBM, in many of the sessions. The ultra-thin carbon sheets have turned the normally staid community into “a herd of rhinos”, says Andre Geim, a physicist at the University of Manchester, UK. And, he adds, “this year, I feel more like applications are what’s driving the field.” Not everyone is sanguine about graphene’s chances for going commercial. Graphene has several problems, notably a lack of an obvious ‘band gap’, a break in electron energy levels that would allow it to be easily used as a transistor, says Kenneth Shepard, an electrical engineer at Columbia University in New York. “There are a lot of problems with this stuff,” he warns, fearing that starry-eyed researchers may overhype this latest material. But others argue that graphene is much more promising than its predecessor, carbon nanotubes. Nanotubes, essentially rolls of graphene, have been difficult to control and integrate into existing electronics, says Tomás Palacios, an electrical engineer at the Massachusetts Institute of Technology in Cambridge. Graphene’s uniformity and flatness make it easier to combine with current silicon technology, and many researchers who once worked on nanotubes are now focusing instead on graphene. The shift was evident at this year’s meeting: there were 16 sessions on nanotubes, whereas graphene had 28. Work on graphene — discovered by Geim and his colleagues almost 5 years ago (K. S. Novoselov et al. Science 306, 666–669; 2004) — heated up quickly as researchers realized that the material’s two-dimensionality caused it to show unusual quantum behaviours (see Nature 438, 201–204; 2005). But graphene also has properties that make it alluring for certain applications. Electrical charge can fly through the sheets at high velocities, up to four times those in silicon. Large thin layers of graphene would be both flexible and transparent. Graphene ribbons might act as transistors, even though bulk graphene does not. And because graphene is so thin, even the slightest brush from neighbouring atoms can alter its mechanical and electrical properties. “It has been a fascinating material,” says Marcus Freitag of IBM’s T. J. Watson Research Center in Yorktown Heights, New York.