Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo


Unsupported browser: Your browser does not meet modern web standards. See how it scores »

{ action.text }

Light detector: A graphene photodetector takes advantage of the electric field that is created at the interface between metal contacts (gold) and graphene. When light falls on graphene, the field helps to separate electrons from holes, leading to an electric current.

A single sheet of graphene absorbs 2.3 percent of the light falling on it, a significant amount for a one-atom-thick material. “You have a photodetector that has a number of advantages: it absorbs over a wide wavelength range, it’s very fast, it has a high absorbance, it’s a single atomic layer,” Avouris says. “This combination makes it rather unique.”

Ultrafast photodetectors could find use in future optical communications networks with data rates beyond 40 gigabits per second; right now, optical networks have data rates of about 10 gigabits per second. The photodetectors could also be used in optical computers that compute with electrons but transfer data using light instead of sending it over heat-prone copper wires. Fengnian Xia, a coauthor of the paper, says that graphene would also make a better detector for terahertz radiation, which has shown promise for medical and security imaging.

“Graphene is a great material for electronics,” says Andre Geim, a professor of physics at the University of Manchester, U.K. “Very few people could think about optoelectronics being of any interest with this material. This is like fresh air.”

The researchers get current in response to light pulses at a frequency of 40 gigahertz. Frequencies higher than this are not possible with today’s electronics, says Avouris, but graphene could, in theory, enable photodetectors that work at frequencies even higher than 0.5 terahertz.

0 comments about this story. Start the discussion »

Credits: IBM T. J. Watson Research Center

Tagged: Computing, Materials, IBM, memory, transistors, graphene, carbon atoms, optoelectronics, photodetectors

Reprints and Permissions | Send feedback to the editor

From the Archives


Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me