▎ 摘　　要

We present an analytical device model for a graphene field-effect transistor (GFET) on a highly conducting substrate, playing the role of the back gate, with relatively short top gate which controls the source-drain current The equations of the GFET device model include the Poisson equation in the weak nonlocality approximation. Using this model, we find explicit analytical formulae for the spatial distributions of the electric potential along the channel and for the voltage dependences of the thermionic and tunneling currents. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.