NEW YORK, April 18 (UPI) -- The carbon sheets that make up the graphite in pencils could serve as the foundation for a new class of electronics just nanometers or billionths of a meter in scale, experts told UPI's Nano World.
These devices could have the attractive electronic properties of carbon nanotubes, which conduct electricity at high speed with little energy loss, yet have the added bonus of being produced using established microelectronics techniques, explained researcher Walt de Heer, a physicist at the Georgia Institute of Technology in Atlanta.
Still, de Heer cautioned practical devices could be a decade away. "There is a long road ahead," he said.
Graphite is made of layers just a single carbon atom thick known as graphene. Carbon nanotubes are simply graphene that has been rolled into a cylindrical shape, de Heer explained.
Investigators worldwide are researching for carbon nanotubes for use in transistors and other devices. However, scientists have faced a great deal of difficulty when it comes producing nanotubes of consistent sizes and electronic properties as well as integrating nanotubes into circuitry using processes suitable for mass production.
De Heer and his colleagues with researchers at the Centre National de la Recherche Scientifique in Paris have created transistors made of graphene with features just 80 nanometers in size and hope to reach a size of just 10 nanometers with new equipment.
In findings reported online April 13 via the journal Science, the researchers found that when electrons are confined in the graphene circuitry, they behave as if they are waves, or virtually massless particles. "Using narrow ribbons of graphene, we can get all the properties of nanotubes because those properties are due to the graphene and the confinement of the electrons, not the nanotube structures," de Heer said.
"This will allow the production of very small devices with very high efficiencies and low power consumption," de Heer said.
The future might even include chips made completely of graphene. "One trouble carbon nanotube electronics have conceptually is that contact between wires and carbon nanotubes is poor, which can lead to a lot of resistance at the contact," de Heer said. "In our concept, you would have the entire device made of graphene. That makes sure there are no annoying contact resistances."
Challenges ahead include improving the methods for generating patterns with graphene, since the way the electrons travel is affected by the smoothness of the edges in the circuitry. "We are at the proof-of-principle stage, comparable to where transistors were in the late 1940s," de Heer said. "We have a lot to do, but I believe this technology will advance rapidly."
Physicist Andre Geim at the University of Manchester in England, who with his colleagues and Russian researchers reported the first graphene transistor in 2004, noted, "de Heer and his colleagues show for the first time that industrial scale production of graphene is possible. That will be absolutely major impact for years to come."
