CHAMPAIGN, Ill. — Graphene, a single-atom-thick sheet of carbon, holds remarkable promise for future nanoelectronics applications. Whether graphene actually cuts it in industry, however, depends upon how graphene is cut, say researchers at the University of Illinois.
Graphene consists of a hexagonal lattice of carbon atoms. While scientists have predicted that the orientation of atoms along the edges of the lattice would affect the material’s electronic properties, the prediction had not been proven experimentally.
Now, researchers at the U. of I. say they have proof.
Atomic resolution scanning tunneling microscope image of a nanometer scale piece of graphene on silicon. Photo courtesy Joseph Lyding.
|“Our experimental results show, without a doubt, that the crystallographic orientation of the graphene edges significantly influences the electronic properties,” said Joseph Lyding, a professor electrical and computer |
“To utilize nanometer-size pieces of graphene in future nanoelectronics, atomically precise control of the geometry of these structures will be required.”
“We found that pieces of graphene smaller than about 10 nanometers with predominately zigzag edges exhibited metallic behavior rather than the semiconducting behavior expected from size alone,” Lyding said. “This has major implications in that semiconducting behavior is mandatory for transistor fabrication.”
Unlike carbon nanotubes, graphene is a flat sheet, and therefore compatible with conventional fabrication processes used by today’s chipmakers. But, based on the researchers’ experimental results, controlled engineering of the graphene edge structure will be required for obtaining uniform performance among graphene-based nanoelectronic devices.
“Even a tiny section of zigzag orientation on a 5-nanometer piece of graphene will change the material from a semiconductor into a metal,” Lyding said. “And a transistor based on that, will not work. Period.”
The Office of Naval Research and the National Science Foundation funded the work.
Editor’s note: To reach Joseph Lyding, call 217-333-8370; e-mail: firstname.lastname@example.org.
Contact: James E. Kloeppel, Physical Sciences Editor email@example.com 217-244-1073 University of Illinois at Urbana-Champaign