▎ 摘　　要

In this paper, we present a theoretical evaluation of ballistic electron transport in field-effect transistors (FETs) with semiconducting graphehe channels; bilayer graphenes (BLGs), monolayer graphene nanoribbons (MLGNRs), and bilayer graphene nanoribbons (BLGNRs). We found that the use of BLGNRs produces little advantage in either increasing the band gap energy or improving the device performance, as compared with a pristine BLG device. We also demonstrated that BLG-based FETs exhibit quite different behavior in the drain current versus gate voltage characteristics from that of MLGNR-FETs, since a distorted dispersion relation around the conduction band minima significantly affects the drain current property. (C) 2012 The Japan Society of Applied Physics