Fastest transistor yet boosts graphene's super-status

This week, IBM began something of a band-gap backlash against wunder material graphene. After the computer firm said graphene would never fully replace silicon, a group of scientists in Switzerland announced that there was another two dimensional industrial lubricant with more traditional semi-conductor properties – molybdenum - that could send silicon into retirement.

But now University of Southampton researchers have made a new transistor from graphene with an on/off switching ratio 1000 times higher than previously recorded, bringing graphene right back into the battle. The researchers found that if they introduced “geometrical singularities” (that’s corners, to you and me) into the material, the current flow could be turned off.

Professor Hiroshi Mizuta, Head of the Nano Group acknowledged the difficulties of working with graphene: "Enormous effort has been made across the world to pinch off the channel of GFETs electrostatically, but the existing approaches require either the channel width to be much narrower than 10 nm or a very high voltage to be applied vertically across bilayer graphene layers. This hasn’t achieved an on/off ratio which is high enough, and is not viable for practical use."

So, a research group led by Dr. Zakaria Moktadir tried a new approach and used the University’s new helium ion beam microscope and a focused gallium ion beam system to introduce kinks into a bilayer graphene nanowire. The result was a switching ration 1000 times better than previously reported.

Having established that switching the current off is now possible, the group plans more research to work out exactly why, and how noise and temperature will affect performance and reliability of the device.

The work is published in the February 3 edition of Electronics Letters.