Bandstructure Effects in Phosphorene Nanoribbon MOSFETs from NEGF Simulations Using a New DFT-based Tight-binding Hamiltonian Model

Abstract

Electronic and transport properties of monolayer black phosphorus (phosphorene) make it promising for future nanoscale field-effect transistors (FETs), especially in the form of phosphorene nanoribbons (PNRs). Currently, these devices can be explored appropriately only by means of advanced formalisms such as quantum transport that accounts for atomically-resolved description of the system under study. In this work we report a new tight-binding (TB) model for phosphorene calibrated on ab initio density-functional theory (DFT) calculations that accurately reproduces the bandstructure of PNRs with the widths down to $\sim 0.5$ nm. The new DFT-TB Hamiltonian produces qualitatively and quantitatively different results in terms of PNR FET performance in comparison to the widely used TB model from the literature. We show that PNR FETs with nanoribbon widths larger than $\sim 1.4$ nm can meet industry requirements at the "3 nm" node assuming ballistic transport.