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Summary:

Current manufacturing techniques cause graphene to lose its fantastic characteristics when it’s chopped up. U.S. researchers developed a new way to grow it that could change that.

Graphene

Graphene has amazing properties. It’s strong, flexible and great at conducting heat. But one of its most unusual properties is that electrons move through it as if they were massless, even at room temperature, meaning graphene can conduct electricity 200 times faster than silicon. That could someday lead to faster chips that don’t overheat.

Unfortunately, it’s difficult to preserve graphene’s conductive properties when it is chopped into the tiny pieces that go into a chip. Small strips of graphene, known as nanoribbons, generally have uneven edges that limit how far electrons can travel.

Researchers at the Georgia Institute of Technology in Atlanta just discovered a way to change that. They were able to create nanoribbons with smooth edges, allowing electrons to travel a total of 10 micrometers: 1,000 times further than in current nanoribbons. That’s 10 times better than theorized. They published their work in Nature (subscription required) today.

The Georgia team’s trick was to grow small strips of graphene instead of cutting a larger sheet down to size. They heated a combination of silicon and carbon to more than 1,800 degrees Fahrenheit. The silicon evaporated, leaving behind only graphene.

Nature reported that the reason electrons move through the nanoribbons quickly is that instead of taking an indirect, scattered path, they travel straight down the edges similar to how light travels through optical fibers. That would explain why it’s so important to not have ragged edges, which interrupt the electrons’ flow.

Nature documented some doubt among researchers, including National University of Singapore Graphene Research Center director Antonio Castro Neto, who is skeptical the same results can be accomplished in longer nanoribbons.

“The properties will be wonderful, but will they be as fantastic as those demonstrated? Probably not,” Cambridge Graphene Center director Andrea Ferrari told Nature. “But they may still be sufficient for the needed application, so I am still encouraged.”

  1. Sorry, but I am left confused. Silicon is an insulator, and doesn’t conduct electricity, so I am not sure where “meaning graphene can conduct electricity 200 times faster than silicon” comes from.

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    1. It is also a semiconductor, which is why it is so popular in electronics.

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  2. I think she meant the “drift velocity” of electron in silicon is about 200 times slower than graphene. Drift velocity is the speed of electron movement through a material, which’s not exactly the same as conductivity. At the nano scale (micro/nano transistor scale) the drift velocity is a bigger factor than a material’s conductivity (so I’ve read).

    The only reference I found with drift velocities of graphene and silicon show graphene is about 142 times faster than silicon (http://news.softpedia.com/news/Electrons-100-times-Faster-in-Graphene-81534.shtml). But maybe graphene has gotten faster since 2008 when that article was published.

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  3. It’s worth to mention that Polish scientist has invented a mass production method for graphene. They selling a graphene waffer already. more info: http://www.nauka.gov.pl/en/polish-science-news/poland-among-graphene-research-leaders.html

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