Graphene to replace silicon in next gen ICs?

A team of scientists from the UK's Science and Technology Facilities Council (STFC) took a sample of bilayer graphene – in which two layers of graphene are placed one on top of the other, leaving a small band gap to encourage the transfer of energy between layers – and fired ultra short pump laser pulses to boost electrons into the conduction band. A second short, extreme ultraviolet, wavelength pulse then ejected electrons from the sample. These were collected and analysed to provide a snapshot of the energies and movement of the electrons. "We took a series of these measurements, varying the time delay between the infrared laser pump and extreme ultraviolet probe, and sequenced them into a movie," said STFC's Dr Cephise Cacho. "To see how the fast moving electrons behave, each frame of the movie has to be separated by just a fraction of a billionth of a second." Lead researcher Professor Philip Hofmann, from Aarhus University in Denmark, added: "What we've shown with this research is that our sample behaves as a semiconductor, and isn't short-circuited by defects." The researchers believe the research, in which the graphene showed no defects, suggests that further technological effort should be carried out to minimise imperfections. Once this is done, there is a chance that the switch-off performance of bilayer graphene can be boosted enough to challenge silicon based devices. "Graphene transistors could make smaller, faster electronic chips than are achievable with silicon," Prof Hoffman concluded. "Eventually more and more transistors could be placed onto a single microchip to produce faster, more powerful processors for use in electronic equipment."