Graphene

By: Troy Morse11/22/2009

"We are like dwarfs sitting on the shoulders of giants. We see more, and things that are more distant, than they did, not because our sight is superior or because we are taller than they, but because they raise us up, and by their great stature add to ours."

Only a half century after their development was initiated, integrated circuits have become ubiquitous. Computers, cellular phones, and other digital appliances are now inextricable parts of the structure of modern societies.

Single-layer crystallites of NbSe2 (a), graphite (b), Bi2Sr2CaCu2Ox (c), and MoS2 (d) visualized by AFM (a and b), by scanning electron microscopy (c), and in an optical microscope (d). (All scale bars: 1 micron.) Image and text: Proc. Natl. Acad. Sci. 2005 102 10451

Image: Jannik MeyerGraphene, the hottest new material in electronics, is remarkably simple: a flat sheet of pure carbon rings—just one atom thick—that resembles chicken wire.

Graphene is a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, and is a basic building block for graphitic materials of all other dimensionalities. It can be wrapped up into 0D fullerenes or buckyballs, rolled into 1D nanotubes or stacked into 3D graphite.

Graphene is a single atomic plane of graphite, which—and this is essential—is sufficiently isolated from its environment to be considered free-standing.

The simplest method of exfoliation is can be described as the repeated peeling of 3D graphite crystals.

Epitaxial growth is a method where graphene is ‘grown’ on a substrate of another crystalline substance.

By placing graphite oxide paper into a solution of pure hydrazine the paper will be reduced to a single layer of graphene.

Graphene can be created by slicing a nanotube along the vertical axis.

Drawing represents a probe scanning and mapping the atomic contours of graphene, a single layer of carbon atoms arranged in a honeycomb-like array. Simultaneously applying a magnetic field causes electrons (ball) to organize in circular orbits, like a dog chasing its tail. Orbits hold clues to the material's exotic properties. (Credit: Kubista, Georgia Institute of Technology/NIST)

The scientific community has been praising graphene as some sort of miracle material for years now—even going so far as to say that it could eventually replace silicon. Well, graphene can now add another statistic to its impressive resume now that researchers have confirmed it as the strongest material ever tested.

According to Science News, the researchers found that by heating one side of a magnetized nickel-iron rod they were

able to change the arrangement of the electrons in the material according to their

"spins," which is the quantum-physics equivalent of the south-north magnetic

axes in bar magnets. One of the big advantages of that, it seems, is that,

unlike with electric currents, transferring information by "flipping spins" does not

generate heat, which would let "spintronics devices" operate at higher

speeds without overheating, and cut down on power consumption in the process.

Ultracapacitors could allow laptops and cell phones to be charged in a minute. Unlike laptop batteries, which start to lose their ability to hold a charge after a year or two (several hundred charge/discharge cycles),  ultracapacitors have hundreds of thousands of charge/discharge cycles and could still be going strong long after the device is obsolete.

Double-decker: IBM researchers have found that they can significantly reduce noise in graphene devices by stacking two layers together. Here, the noise produced from a single layer of graphene (left) is compared with that from two layers (right). Credit: IBM

Graphene sheets could detect just a single molecule of nitrogen dioxide

“The high electron mobility of graphene makes it an excellent candidate for analog ultra-high-frequency oscillators and switches” (Johnson).

Q & A

When will the public be able to see this available?

Professor De Heer has already proven the use of graphene in transistors. He demostrated a microchip with only a few thousand transistors. Reviewing the previous graph, based on Moore’s Law, we should expect to see this on the market within the next couple of years.

How will this be used in the gaming industry?

That’s a good question. As I’ve mentioned graphene will make available much smaller and faster digital devices. Also, it’s expected to have an enormous effect on displays, both standard and touch screen. I cannot tell the future, but I will go as far as saying I believe it will bring about the next revolution in gaming; making games more realistic, faster and more powerful.

Can we expect to see as rapid an increase in technology as we did with silicon based chips?

Rapid is good way to put it. The more advanced out chips get, the more we discover. We couldn’t have discovered graphene without the use of silicon based technology. I’d expect to see increases in technology even more rapidly if it delivers on all it’s promises.