Tag Archives: graphene

Andre Geim: in praise of graphene

[div class=attrib]From Nature:[end-div]

Nobel laureate explains why the carbon sheets deserved to win this year’s prize.

This year’s Nobel Prize in Physics went to the discoverers of the one-atom-thick sheets of carbon known as graphene. Andre Geim of the University of Manchester, UK, who shared the award with his colleague Konstantin Novoselov, tells Nature why graphene deserves the prize, and why he hasn’t patented it.

In one sentence, what is graphene?

Graphene is a single plane of graphite that has to be pulled out of bulk graphite to show its amazing properties.

What are these properties?

It’s the thinnest possible material you can imagine. It also has the largest surface-to-weight ratio: with one gram of graphene you can cover several football pitches (in Manchester, you know, we measure surface area in football pitches). It’s also the strongest material ever measured; it’s the stiffest material we know; it’s the most stretchable crystal. That’s not the full list of superlatives, but it’s pretty impressive.

A lot of people expected you to win, but not so soon after the discovery in 2004. Were you expecting it?

I didn’t think it would happen this year. I was thinking about next year or maybe 2014. I slept quite soundly without much expectation. Yeah, it’s good, it’s good.

Graphene has won, but not that much has actually been done with it yet. Do you think it was too soon?

No. The prize, if you read the citation, was given for the properties of graphene; it wasn’t given for expectations that have not yet been realized. Ernest Rutherford’s 1908 Nobel Prize in Chemistry wasn’t given for the nuclear power station — he wouldn’t have survived that long — it was given for showing how interesting atomic physics could be. I believe the Nobel prize committee did a good job.

Do you think that carbon nanotubes were unfairly overlooked?

It’s difficult to judge; I’m a little afraid of being biased. If the prize had been given for bringing graphene to the attention of the community, then it would have been unfair to take it away from carbon nanotubes. But it was given for graphene’s properties, and I think carbon nanotubes did not deliver that range of properties. Everyone knows that — in terms of physics, not applications — carbon nanotubes were not as successful as graphene.

Why do you think graphene has become so popular in the physics community?

I would say there are three important things about graphene. It’s two-dimensional, which is the best possible number for studying fundamental physics. The second thing is the quality of graphene, which stems from its extremely strong carbon–carbon bonds. And finally, the system is also metallic.

What do you think graphene will be used for first?

Two or three months ago, I was in South Korea, and I was shown a graphene roadmap, compiled by Samsung. On this roadmap were approximately 50 dots, corresponding to particular applications. One of the closest applications with a reasonable market value was a flexible touch screen. Samsung expects something within two to three years.

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The Graphene Revolution

[div class=attrib]From Discover:[end-div]

Flexible, see-through, one-atom-thick sheets of carbon could be a key component for futuristic solar cells, batteries, and roll-up LCD screens—and perhaps even microchips.

Under a transmission electron microscope it looks deceptively simple: a grid of hexa­gons resembling a volleyball net or a section of chicken wire. But graphene, a form of carbon that can be produced in sheets only one atom thick, seems poised to shake up the world of electronics. Within five years, it could begin powering faster and better transistors, computer chips, and LCD screens, according to researchers who are smitten with this new supermaterial.

Graphene’s standout trait is its uncanny facility with electrons, which can travel much more quickly through it than they can through silicon. As a result, graphene-based computer chips could be thousands of times as efficient as existing ones. “What limits conductivity in a normal material is that electrons will scatter,” says Michael Strano, a chemical engineer at MIT. “But with graphene the electrons can travel very long distances without scattering. It’s like the thinnest, most stable electrical conducting framework you can think of.”

In 2009 another MIT researcher, Tomas Palacios, devised a graphene chip that doubles the frequency of an electromagnetic signal. Using multiple chips could make the outgoing signal many times higher in frequency than the original. Because frequency determines the clock speed of the chip, boosting it enables faster transfer of data through the chip. Graphene’s extreme thinness means that it is also practically transparent, making it ideal for transmitting signals in devices containing solar cells or LEDs.

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