Low-resistance graphene hexagonal-mesh opens prospect of terahertz transistors

Transistors made of a form of carbon found in pencils could be used to create processors clocking hundreds of times faster than today's silicon-based products, according to a US researcher.

Graphene, which consists layers of a two-dimensional chicken-wire mesh of carbon atoms, has a much lower resistance than silicon and is a good thermal conductor.

This means it would not only generate less heat than silicon at a similar operating state but would more easily cooled.

Professor Walter de Heer, of Georgia Institute of Technology, told a Washington conference that he had succeeded in creating an array of graphene transistors just one atom thick, according to a report in the MIT Technology Review.

Graphene, like silicon, can be doped to display the semiconducting properties needed for transistor switches and it is unclear what method De Heer used. His work has attracted a lot of interest because grapheme processors could be made using methods similar to those used for silicon.

De Heer believes graphene transistors could clock a terahertz or even faster. Intel has talked of pushing silicon transistors to a terahertz, but even if it succeeded it would be pushing the material to the absolute limits.

However, in 2004 it put a temporary cap of 4GHz on CPU clock rates, and used multiple cores instead of higher frequencies to boost processing speed. No Intel procesor has since been rated at 4GHz or higher.

The trends towards mobile computing, and concern about the environment and energy costs, has led to an increased emphasis on power efficiency. So the low power requirements of graphene could, if the research bears fruit, turn out to be as important as its ability to clock faster.