The University of Manchester has proved graphene is the fastest semiconductor.

“We knew this material is exceptionally good, but we couldn’t put a number on it,” Professor Andre Geim, director of the University’s Centre for Mesoscience and Nanotechnology told Electronics Weekly.

His team has proved mobility is above 200,000cm2/Vs at room temperature. “Greater than 100 times that of silicon, 30 times GaAs, and larger even than carbon nanotubes,” he said. “It is the only material where electrons at room temperature can move thousands of interatomic distances without scattering.”

Graphene is a chicken wire-like array of carbon atoms - effectively a single layer of graphite.

Manchester was behind the technique of isolating graphene by rubbing a lump of graphite to flake it off in sheets. “This technique will always remain the technique of choice for research and proof-of-concept,” said Geim. “Now people are finding ways of making graphene in bulk, but they are still not single layer.”

Ideally one layer only, or two at the most, of graphene would be grown on a substrate. More than this and the astounding mobility does not appear.

“Graphene which is now grown epitaxially using SiC underneath is very thin, with perhaps five to seven layers: good enough for chemical sensors, but still not good enough for electronic circuits,” said Geim.

According to him, powdered graphene is available and looking useful. “Many groups are making powder and spinning it on to surfaces for interconnect,” he said. The resulting film is transparent and could be used in displays.

Emphasising that work is “very preliminary”, Geim said: “Its nearest equivalent is ITO [indium tin oxide] and graphene is a slight electrical improvement, but the biggest advantage is indium is too expensive. Powdered graphene is certainly less expensive, easier to produce, and spinning is easier than vacuum deposition.”

Geim believes graphene-based devices like chemical gas sensors, and THz sources and detectors, could begin to materialise within three to five years.

Manchester has been working with The Institute for Microelectronics Technology in Russia, The University of Nijmegen in the Netherlands and The Department of Physics at Michigan Technological University.