摘要：Radio-frequency application of graphene transistors is attracting much recent attention due to the high carrier mobility of graphene. The measured intrinsic cut-off frequency ( f T) of graphene transistor generally increases with the reduced gate length ( L gate) till L gate = 40 nm, and the maximum measured f T has reached 300 GHz. Using ab initio quantum transport simulation, we reveal for the first time that f T of a graphene transistor still increases with the reduced L gate when L gate scales down to a few nm and reaches astonishing a few tens of THz. We observe a clear drain current saturation when a band gap is opened in graphene, with the maximum intrinsic voltage gain increased by a factor of 20. Our simulation strongly suggests it is possible to design a graphene transistor with an extraordinary high f T and drain current saturation by continuously shortening L gate and opening a band gap.
