The subthreshold leakage current in transistors has become a critical limiting factor for realizing ultralow-power transistors. The leakage current is predominantly dictated by the long thermal tail of the charge carriers. We propose a solution to this problem by using narrow-bandwidth semiconductors to limit the thermionic leakage current by filtering out the high-energy carriers. We specifically demonstrate this solution in transistors with a laterally confined ${\text{MoSi}}_2{\text{N}}_4$ monolayer with different passivation serving as channel material. Remarkably, we find that the proposed narrow-bandwidth devices can achieve a large on:off current ratio with an ultralow-power supply voltage of $\sim 0.1\text{V}$, even for devices with $\sim 5\mathrm{nm}$ gate length. We also show that several other materials share the unique electronic properties of narrow-bandwidth conduction and valence bands in the same series.

• Received 21 November 2022
• Revised 11 April 2023
• Accepted 21 April 2023

DOI:https://doi.org/10.1103/PhysRevApplied.19.064058