Dirac-source field-effect transistors as energy-efficient, high-performance electronic switches

Abstract

An efficient way to reduce the power is to lower the supply voltage VDD, but this voltage is restricted by the 60 millivolts per decade thermionic limit of subthreshold swing (SS) in field-effect transistors (FETs). We show that a graphene Dirac source (DS) with a much narrower electron density distribution around the Fermi level than that of conventional FETs can lower SS. A DS-FET with a carbon nanotube channel provided an average SS of 40 millivolt per decade over four decades of current at room temperature and high device current I60 of up to 40 microampere per micrometer at 60 millivolts per decade. When compared with state-of-the-art Si 14-nanometer node FETs, a similar Ion is realized but at much lower supply voltage of 0.5 versus 0.7 volts for Si, and a much steeper SS below 35 millivolts per decade in the off-state.