▎ 摘　　要

We propose and analyze an approach to secure a high on/off current ratio in a graphene field effect transistor (FET) by introducing a physical gap along the channel rather than by attempting to open the energy bandgap of graphene. The device simulation results of the newly proposed device structure reveal highly suppressed off-state current of similar to 10(-9) A/mu m, an on/off current ratio of more than seven orders of magnitude, and a subthreshold slope of 2.23 mV/decade more than a 20-fold reduction relative to the theoretical limitation of conventional metal-oxide-semiconductor FETs. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4756795]