Method to enhance resonant interlayer tunneling in bilayer-graphene systems

Energy- and momentum-conserving resonant tunneling observed between two layers of two-dimensional semiconductors could be used to create interlayer tunnel field-effect transistors (ITFETs), which could have digital and analog applications, including neuromorphic computing. Two key metrics that decide the quality of ITFETs are the resonance width and the relative magnitude of the background current. Lower resonance widths and background currents are desirable to build power-efficient circuits with reduced operating voltages. In this work, we investigate the use of multiple tunnel barriers to create a multi-barrier ITFET (or mITFET) to improve these metrics. We study the electron transport in the ballistic limit in which the electron coherently tunnels across the entire tunnel-barrier stack without scattering. We show that a background current reduction is possible with the introduction of at least one additional tunnel barrier and the resonance width is dramatically reduced with the introduction of two tunnel barriers compared to an ITFET.