Analysis of ballistic monolayer and bilayer graphene field-effect transistors

We examine and compare ballistic performance limits of metal-oxide-semiconductor field-effect transistors with monolayer and bilayer graphene channels. Under low source-drain biases and cryogenic temperatures, the leakage current of the bilayer device is orders of magnitude smaller than that of the monolayer device. The advantage lowers at raised temperatures and source-drain biases. The bilayer device, however, still has qualitatively different and more favorable I-V characteristics. We find the ballistic on-state channel conductance and the minimum channel conductance have distinctly different dependences on the channel length.