Researchers at the University of Manchester, UK, are using the world’s thinnest material to build novel electronics devices, in a move that should accelerate the development of electronics for a post-silicon age.
Andre Geim, a world leading expert on graphene, together with his colleague Kostya Novoselov, had published recently in Nature Materials a review (subscription required) of the state of graphene research. Graphene is a single planar sheet of carbon atoms, and graphenes are the two-dimensional counterparts of three-dimensional graphite.
Geim and Novoselov’s review focuses on the physics of graphene, but the authors also discuss potential practical applications of the material, including in electronics. For example, they refer to room-temperature ballistic transistors, in which the flow of electrons is unimpeded by collisions with atoms.
But an even more exciting possibility is to use graphene not as a new material for field-effect transistors (FET), but as a conductive sheet in which nanometre-sized structures can be carved to make a single-electron transistor (SET). An SET based on graphene exploits the fact that the material’s nanostructures are stable possibly down to the size of a single benzene ring.
The mass production of such devices remains some way off. but talk of the post-silicon age is not premature. Miniaturisation of silicon-based electronics proceeds apace, but Moore’s Law will not hold for much longer in its original form.
Geim and his colleagues – who have formed a spin-off company called Graphene Industries – are at the forefront of research into graphene and its uses. “We make proof-of-concept devices and demonstrate what is possible,” says Geim. “But other groups with more appropriate expertise in crystal growth have already demonstrated graphene wafers suitable for large scale applications. When the aim is clear, people tend to apply various techniques, and some of them should eventually work. Having said that, even the very first approach – using epitaxy on a silicon carbide surface – is already working.”
Geim adds that non-transistor applications of graphene, such as for composite materials and electrical batteries, are likely within five years.
Image: Jannik Meyer, University of Manchester.
Article first published in Nanomaterials News.