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

An efficient way to reduce the power is to lower the supply voltage V DD , 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 I 60 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 I on 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.