Theoretical evaluation of channel structure in graphene field-effect transistors

Energy band structures for monolayer and bilayer armchair graphene nanoribbons on SiC substrates are investigated using a nearestneighbor tight-binding approximation with two distinct models (interlayer coupling and substrate-induced asymmetry models). Differences in the band structures and charge distributions based on the two models are clarified. The calculation results suggest that wide films of bilayer armchair graphene on SiC substrates should be used for electronics applications such as graphene-channel field-effect transistors.