In a paper published this week in Science, a Manchester team lead by Nobel laureates Professor Andre Geim and Professor Konstantin Novoselov has literally opened a third dimension in graphene research. Their research shows a transistor that may prove the missing link for graphene to become the next silicon.
Graphene one atomic plane of carbon is a remarkable material with endless unique properties, from electronic to chemical and from optical to mechanical.
One of many potential applications of graphene is its use as the basic material for computer chips instead of silicon. This potential has alerted the attention of major chip manufactures, including IBM, Samsung, Texas Instruments and Intel. Individual transistors with very high frequencies (up to 300 GHz) have already been demonstrated by several groups worldwide.
Unfortunately, those transistors cannot be packed densely in a computer chip because they leak too much current, even in the most insulating state of graphene. This electric current would cause chips to melt within a fraction of a second.
This problem has been around since 2004 when the Manchester researchers reported their Nobel-winning graphene findings and, despite a huge worldwide effort to solve it since then, no real solution has so far been offered.
The University of Manchester scientists now suggest using graphene not laterally (in plane) as all the previous studies did but in the vertical direction. They used graphene as an electrode from which electrons tunnelled through a dielectric into another metal. This is called a tunnelling diode.
Then they exploited a truly unique feature of graphene that an external voltage can strongly change the energy of tunnelling electrons. As a result they got a new type of a device vertical field-effect tunnelling transistor in which graphene is a critical ingredient.
Dr Leonid Ponomarenko, who spearheaded the experimental ef
|Contact: Daniel Cochlin|
University of Manchester