The adage there's nothing new under the sun may be true, but sometimes that which we know can take on new shape and meaning. Such is the case with graphene, a material comprised of a single plane of atoms “pulled” from conventional graphite. The inverse way of conceptualizing this is that common graphite is made up of layers of graphene.
Jointly discovered by Dr. Kostya Novoselov and Professor Andre Geim at the School of Physics and Astronomy at The University of Manchester in England, graphene can actually form molecule-sized transistors. This breakthrough is so important that Novoselov and Geim were awarded the Europhysics Prize for Condensed Matter Physics for discovering graphene and its electronic properties.
Especially intriguing is that as you make graphene transistors smaller, they will likely tend to outperform silicon devices. Researchers are
discussing graphene devices with feature sizes smaller than 10 nm. In the lab, graphene-based single-electron transistors have already been fabbed with feature sizes of about 30 nm. Amazingly, these experimental devices have demonstrated the ability to control the motion of single electrons.
Supplanting SiliconHere in the US, researchers at Rensselaer Polytechnic Institute support the idea that graphene may ultimately supplant the role of silicon in nanoelectronic devices, especially for analog ICs. So far, the folks at RPI have run computer simulations showing graphene nanoscale ribbons exhibiting metallic conduction as well as semiconducting behaviors.
The material's energy gaps determine if graphene is metallic or semiconducting. These mixed properties promise nanoscale devices that could also be used as replacements for copper interconnects on ICs, as well as for the active devices themselves. At 25°C, graphene is an excellent metallic-like conductor. Researchers are hoping that graphene interconnects at the die level may run cooler than copper interconnects of the same dimensions.
Magic Properties"Graphene continues to surprise us beyond our wildest imagination," said professor Geim, when presented with the Europhysics Prize. "It's just the tip of an iceberg. It works like a magic wand. Whatever property or phenomenon you address with graphene, it brings you magic."
Geim and others note that prior studies had suggested two-dimensional graphene crystals would be destroyed by thermal fluctuations at any temperature. However, graphene has now been processed into freestanding membranes that exhibit perfect crystal structures regardless of temperature change.
Moreover, graphene's ability to transport charge carriers, and its electric field effects, suggest the substance may indeed replace silicon in electronic applications – perhaps sooner than most people realize. Geim is a sanguine convert. “We're on the verge of graphene-based technologies,” he says. "In ten years time graphene will be as common as silicon is today."
Is graphene pie-in-the-sky? What are your thoughts? Write me at
amm at en-genius dot net, or post your comments on our blog.
