MIT Discovers that Graphene can Generate Electric Current; Improvements to Night Vision and Solar Energy Systems Could be Next

Posted by erik devaney

Courtesy of cnx.org

Graphene is one of the most bizarre and, at the same time, amazing substances on the planet.

Like the similar-sounding and more common substance, graphite, the exotic substance graphene consists of carbon. However, unlike graphite, graphene is composed of sheets of carbon, each a single atom thick. More notably, graphene – pound for pound – is the strongest material on the planet.

Researchers at MIT recently discovered that the uncanny strength of graphene allows it to have an unusual reaction to light. By shining light on a sheet of graphene (after treating it to create two regions with different electrical properties), the researchers found that they could create a temperature difference within the sheet. That temperature difference, in turn, can generate an electric current.

With most substances, incoming energy from light is transferred with relative ease, which is why substantial temperature differences within those substances do not occur. However, because graphene is so strong, energy has a tough time passing through it. As a result, the nuclei of the carbon atoms inside the graphene remain cool, while the electrons heat up.

This phenomenon is known as a hot-carrier response. And, according to MIT researcher, Pablo Jarillo-Herrero, it is “very unusual.”

“Many people believe that graphene could be used for a whole variety of applications,” Jarillo-Herrero recently commented. However, because the graphene/hot-carrier phenomenon is such a recent discovery, it’s hard to know for sure what its applications will be.

Still, Jarillo-Herrero does have some ideas.

For example, because hot-carrier graphene can detect a broad spectrum of energy wavelengths, including infrared, it could be useful in night-vision systems and telescopes.

In addition, the graphene’s ability to respond to varying wavelengths makes it a prime candidate for collecting solar energy. More traditional solar materials, in comparison, can only respond to limited frequencies of light.

Graphene, in light of this recent MIT research, could also prove to have medical applications. Because toxins and contaminants often give off infrared light when illuminated, we may eventually be able to use graphene to detect disease-causing agents.

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Posted by erik devaney on Oct 7 2011. Filed under Technology. You can follow any responses to this entry through the RSS 2.0. You can leave a response or trackback to this entry