Technical Insight
Plasmarons 'give graphene unique properties'
Particles found in graphene could hold the key to the material's development as a basis for next-generation photonics research.
An international team of researchers led by Aaron Bostwick and Eli Rotenberg of the Advanced Light Source (ALS) at the US Department of Energy's Lawrence Berkeley National Laboratory has unlocked some of the mysteries of the unique properties of graphene.
The team showed how plasmarons - a charge carrier coupled with a plasmon particle - could play an integral role in the development of super-fast computers using graphene for room-temperature applications in the future.
It revealed how the density of graphene's electrical charge carriers can be easily influenced, thereby making it relatively straightforward to tune the electronic properties of graphene nanostructures.
The team revealed how the material has no band-gap and this could be one of the unique selling points for its use in next-generation electronics.
"On the usual band-gap diagram of neutral graphene, the filled valence band and the empty conduction band are shown as two cones, which meet at their tips at a point called the Dirac crossing," Dr Bostwick commented.
As particles get close to the Dirac crossing they move as if they have no mass, travelling at a specific proportion of the speed of light. As a result, the introduction of photons could excite plasmon particles using external sources, thereby channelling the particles into specific conical bands - making the material easily manageable to meet the needs of computer development.
Dr Rotenberg added that "one of the best ways to grow a flat sheet of graphene is by heating a crystal of silicon carbide (SiC) ... As the silicon recedes from the surface it leaves a single carbon layer".
