Semiconducting Graphene CreatedCategory: Science & Technology
Posted: November 20, 2012 12:30PM
Graphene, that amazing atom-thick allotrope of carbon, has been viewed as the possible replacement for silicon in modern electronics since it was discovered. Considering its high electron mobility and strength, this is not too surprising, but development of graphene electronics has been delayed because graphene behaves like a conductor, instead of a semiconductor. Now researchers at the Georgia Institute of Technology have found a way to make semiconductor graphene at a large scale.
What makes a material a semiconductor is its bandgap. This is the energy difference between the conducting and non-conducting electron bands of a material, so at least that much energy must be applied for a signal to be transmitted through a device. Graphene typically does not have a bandgap but it has been theorized that by bending it, the physical deformation will affect the material's electronic properties, and this is apparently the case. The researchers grew two layers of graphene on top of a silicon carbide substrate with grooves etched into it. As the graphene grows, it falls into these grooves, creating the bends needed to become a semiconductor.
The next step will be to better understand what is going on here, as the size of the grooves may affect the bandgap. Not only could this knowledge lead to even more advanced devices than currently envisioned, it may be able to explain why the band gap the researchers measured is actually greater than theory predicts for the bends they introduced.