Graphene may be best conductor ever
By Ron Wilson, Executive Editor -- EDN, February 7, 2008
Researchers at the University of Manchester in the United Kingdom, working in conjunction with teams at the Institute for Microelectronics Technology and High Purity Materials in Russia, the Radboud University Nijmegen in the Netherlands, and the department of physics at Michigan Technological University, have concluded that graphene—a monatomic-thickness sheet of carbon atoms connected by sp² bonding—offers the greatest intrinsic mobility of any known material. To the researchers’ surprise, graphene sheets, with a mobility of 200,000 cm²/Vsec, beat out both carbon nanotubes—essentially tubes formed by rolling up graphene—and current research darling indium antimonide. That intrinsic mobility is more than 100 times that of bulk silicon.
“Graphene exhibits the highest electronic quality among all known materials—higher than copper, gold, silicon, gallium arsenide, carbon nanotubes, and anything we know,” says Professor Andre Geim, director of the University of Manchester’s Centre for Mesoscience and Nanotechnology. “It is the only material where electrons at room temperature can move thousands of interatomic distances without scattering.” Because mobility translates directly into both intrinsic speed for MOS transistors and conductance in interconnect, the findings imply that graphene could be the material of choice for future terahertz-speed circuits.
