Graphene the future silicon

Researchers at Manchester University have found that graphene could be the best possible material for electronic applications because of its semiconducting qualities.

The study also opens doors for new applications such as ultra-high frequency detectors for full-body security scanners, which could operate at terahertz frequencies.

‘Graphene is the only material where electrons at room temperature can move thousands of interatomic distances without scattering,’ said Prof Andre Geim, director of Manchester University’s Centre for Mesoscience and Nanotechnology.

‘We knew that it could be a long distances – and longer than for silicon – but before our latest work we did not know, nor expected, that graphene could beat carbon nanotubes or the record holder Indium antimonide (InSb). Our work singles it out as the best possible material for electronic applications.’

The scientists discovered that electrons move more easily in graphene than all other materials, including gold, silicon, gallium arsenide and carbon nanotubes. They claim that this could benefit the future development of ultra-high frequency transistors and wiring in electronic circuits.

Graphene's carrier mobility - 200,000cm2/Vs - was more than 100 times higher than that of silicon.

‘Our findings mean it is worth investing even more effort to develop the material into viable products. Neither graphene nor carbon nanotubes can hope to compete with silicon for about another 20 years. The advantage of graphene is that it still holds a lot of promise,’ said Geim.

Geim admitted that there are some obstacles to overcome before graphene could become more widely available, but that the challenges were not the same as those encountered by the development of nanotubes, which were impossible a few years ago and are still impossible today.

‘The major problem is that graphene is not yet available in wafers suitable for mass production. For some applications, like the substitution of silicon as a basic material for electronics it is not feasible for the next twenty years, but for applications like coating for solar cells or for liquid crystals, it would be feasible in the next three to five years,’ he said.

‘With nanotubes, there are hundreds of different varieities of nanotubes so after ten years, it is still very hard to get a homogenous material.’

The research was carried out in conjunction with the Institute for Microelectronics Technology in Russia, the University of Nijmegen in the Netherlands and the Department of Physics at Michigan Technological University in the US.