Researchers at the Georgia Institute of Technology in Atlanta have devised a new way to make graphene-based digital applications, potentially laying another milestone towards finally replacing silicon in computers.
A team led by physicist Walt de Heer has made graphene ribbons that conduct electricity for more than 10 micrometers without meeting resistaance. That’s 1,000 farther than previous attempts, and that’s not even the exciting bit. The real kicker was the speed at which electrons passed from one end of the nanoribbon to the other – 10 times faster than standard theories suggested. The results baffled the physicists, leading them to believe that their already-bold estimates had been way off. The findings were published in Nature magazine.
Cooler chips, faster computers
Graphene is an exotic material that has the potential to revolutionize the computing industry. With Walt de Heer’s findings, circuits could transmit signals much faster and without the overheating issues associated with traditional silicon chips.
According to de Heer, electrons move down the edges of the ribbons much in the same way light travels down an optical fibre. In a standard conductor – such as a copper – electrons bump and scatter, wasting energy while also generating heat. Graphene not only promises to address these issues, but also to make chips much faster.
Scientists are excited
“The team have been improving both the substrate and the graphene layer on top for about ten years,” said Francisco Guinea, a theoretical physicist at the Institute of Materials Science in Madrid, adding that the evidence for this ‘ballistic’ transport was convincing. “And indeed now they are bearing the fruits of their work,” he said.
James Tour, an organic chemist at Rice University in Houston, Texas, described the results as ”remarkable.” Tour, who also works on graphene nanoribbons, believes the new findings are going to serve as a landmark in the ongoing effort to replace silicon with graphene in computers.
Barking at the wrong tree?
While most scientists are optimistic about these results, some are skeptical about switching to graphene-based electronics. Antonio Castro Neto, director of the National University of Singapore’s Graphene Research Centre, doesn’t believe it’s possible to use the material in digital applications. Disorder due to imperfections will destroy the rapid conduction, he says.
Neto believes phosophorene stands a much better chance of being successfully used in computer chips. Phosphorene is similar to graphene in that it’s also one-atom-thick. This one, however, goes the extra mile in semi-conductivity because it has a natural band gap – where electrons cannot exist freely allowing the flow to be switched on and off.
The good news is that, as we edge closer to the physical limits of silicon, we have not one but two promising options to explore.