Anisotropic transport and scaling trends of pentagonal two-dimensional NiN2 metal–oxide–semiconductor field-effect transistors

Abstract

Pentagonal 2D materials have attracted significant interest for their unique physical properties and low-symmetry lattices. In this work, we investigate the transport properties of pentagonal monolayer NiN2 in sub-10 nm metal–oxide–semiconductor field-effect transistors using non-equilibrium Green’s function simulations with machine-learning tight-binding Hamiltonians. Our simulations reveal direction-dependent behavior, with devices oriented along the 45° axis exhibiting more pronounced short-channel effects than those along the 0° direction. N-type devices consistently deliver higher ON current than p-type devices due to the larger density of states near the conduction band edge, while p-type subthreshold performance degrades more significantly than n-type devices at short channel lengths due to relatively smaller hole effective mass and larger source-to-drain tunneling. Using a high-κ HfO2 gate dielectric, both n- and p-type NiN2 devices with channel lengths (Lch) of 5–10 nm meet the International Roadmap for Devices and Systems high-performance 2037 targets, while the high-density specifications are satisfied for Lch ≥ 6 and 8 nm, respectively. These findings highlight monolayer NiN2 as a promising material platform for future 2D-material electronics and offer valuable guidance for their device design.