(a)–(c) Schematic description of the transistor structures considered in Fig. 2. (a) The standard source gated transistor (SGT). (b) The double work function DIFT (DWF-DIFT). (c) The double doped function DIFT (DDF-DIFT). The light blue regions depict the depletion, which in (b) and (c) corresponds to the Schottky region of the source electrode (Ls). The dark green lines illustrate the current path. (d) Calculated band structure under the source contact at two distinct regions. The blue line is within the Schottky (undoped) region, and the orange line is in the doped region.