Lateral Heterostructure Field-Effect Transistors Based on Two-Dimensional Material Stacks with Varying Thickness and Energy Filtering Source

The bandgap dependence on the number of atomic layers of some families of two-dimensional (2D) materials can be exploited to engineer and use lateral heterostructures (LHs) as high-performance field-effect transistors (FETs). This option can provide very good lattice matching as well as high heterointerface quality. More importantly, this bandgap modulation with layer stacking can give rise to steep transitions in the density of states (DOS) of the 2D material that can eventually be used to achieve sub-60 mV/decade subthreshold swing in LH-FETs thanks to an energy-filtering source. We have observed this effect in the case of a PdS 2 LH-FET due to the particular DOS of its bilayer configuration. Our results are based on ab initio and multiscale materials and device modeling and incite the exploration of the 2D-material design space in order to find more abrupt DOS transitions and better suitable candidates.