Stanford Advanced Materials http://www.samaterials.com

Graphene The “Next Big Thing”

The use of graphene in everyday life is not far off, due in part to existing research into carbon nanotubes

— the rolled, cylindrical version of graphene. The tubes were popularized by a 1991 paper and pushed

for their incredible physical qualities, most of which are very similar to graphene. But it is easier to

produce large sheets of graphene and it can be made in a similar way to silicon. Many of the current and

planned applications for carbon nanotubes are now being adapted to graphene.

Much has been made of graphene's potential. It can be used for anything from composite materials -

like how carbon-fiber is used currently - to electronics. It is a good thermal and electric conductor and

can be used to develop semiconductor circuits and computer parts. Experiments have shown it to be

incredibly strong.

Perhaps we could soon see security-orientated clothing manufactured from graphene-enhanced

photovoltaic cells and super capacitors that could repel the use of electrical discharge. Furthermore we

could even be able to charge mobile telephones and tablet computers in a matter of minutes

(potentially even seconds) outdoor.

So what is this new wonder material?

Graphene is the strongest and the most conducive material ever known to man. In simple terms it is a

single, thin, tightly packed layer of carbon atoms arranged together into a hexagonal two-dimensional

honeycomb lattice. In more complex terms, it is an allotrope of carbon in the structure of a plane of sp2

hybridized carbon atoms with a molecule bond length of 0.142 nanometers. Layers of graphene stacked

on top of each other form graphite, with spacing of 0.335 nanometers.

It is the thinnest compound known to man at one atom thick, the lightest material known (with 1 square

meter coming in at around 0.77 milligrams), the strongest compound discovered (between 100-300

times stronger than steel and with a tensile stiffness of 150,000,000 psi), the best conductor of heat at

room temperature (at (4.84±0.44) × 103 to (5.30±0.48) × 103 W·m−1·K−1) and also the best conductor

of electricity known (studies have shown electron mobility at values of more than 15,000 cm2·V−1·s−1).

Other notable properties of graphene are its unique levels of light absorption at πα ≈ 2.3% of white light,

and its potential suitability for use in spin transport.

Arguably graphene was discovered in the most diffident of ways, with just two scientists and a bit of

scotch tape. However its potential is anything but diffident. With excitement growing as graphene paves

the way to make the impossible, possible. The 21st century could see, invisibility cloaks, smart phones

that last weeks between charges, smaller and faster electronics that can be folded, rolled or squashed!