Computer processors may soon have one fundamental aspect in common with their owners – a structure composed largely of carbon, rather than silicon.
Graphene, carbon arranged in atom-thick sheets, is already known to be an excellent conductor, but electronics requires the ability to insulate too, as well as electrical properties in between those two extremes.
Now research has shown that the material can be easily modified to act as an insulator, paving the way for efficient all-carbon electronics (see our feature What happens when silicon can shrink no more?).
The semiconductor industry exploits the "whole periodic table" to manufacture its components, says Konstantin Novoselov at the University of Manchester, UK. "But what if a single material is modified so that it covers the entire spectrum needed for electronics?" Graphene could be that material, he says.
Discovered in 2004, graphene is made from sheets of carbon atoms in a hexagonal "chicken wire" arrangement. The material is an ideal conductor –
electrons whiz through the layers at near the speed of light.
Novoselov and colleagues have shown the material can be easily modified to act as an insulator by adding hydrogen atoms to its surface. The new material – called graphane – is made by exposing a graphene sheet to ionised hydrogen gas for two hours.
The carbon-hydrogen bonds created lock away electrons that in graphene are free to move as current.