David Kirkpatrick

December 17, 2008

Graphene improving transistors

Haven’t blogged about the nanotech material graphene in a while. Here’s some exciting news from Technology Review.

From the link:

A pair of research groups, working independently, report making graphene-based transistors that work at the highest frequencies reported to date. The new transistors are a promising first step toward ultrahigh radio-frequency (RF) transistors, which could be useful for wireless communications, remote sensing, radar systems, and weapons imaging systems.

The reports come from researchers at the IBM T. J. Watson Research Center in Yorktown Heights, NY, and at the HRL Laboratories in Malibu, CA. The IBM transistors work at frequencies up to 26 gigahertz. Both the IBM and HRL work was funded by the U.S. military’s Defense Advanced Research Projects Agency (DARPA). Kostya Novoselov, a physicist and graphene researcher at the University of Manchester, in the U.K., says that the results are “a really big step forward to demonstrating that high-frequency graphene transistors should work.”

Graphene, a flat sheet of carbon atoms, is a promising material for RF transistors. Typical RF transistors are made from silicon or more expensive semiconductors like indium phosphide. In graphene, for the same voltage, electrons zip around 10 times faster than in indium phosphide, or 100 times faster than in silicon.

Graphene transistors will also consume less power and could turn out to be cheaper than those made from silicon or indium phosphide. Yu-Ming Lin, who led the work at IBM, says that silicon technology is extremely mature, but graphene could “achieve device performance that may never be obtained with conventional semiconductors.”

Jeong-Sun Moon, HRL Laboratories

Speedy carbon devices: Researchers at HRL Laboratories create high-frequency transistors on top of two-inch-wide graphene pieces by patterning metal electrodes and depositing insulating aluminum oxide on top of the graphene. Credit: Jeong-Sun Moon, HRL Laboratories