Improving the Performance of Arsenene Nanoribbon Gate-All-Around Tunnel Field-Effect Transistors Using H Defects.

We systematically study the transport properties of arsenene nanoribbon tunneling field-effect transistors (TFETs) along the armchair directions using first-principles calculations based on density functional theory combined with the non-equilibrium Green's function approach. The pristine nanoribbon TFET devices with and without underlap (UL) exhibit poor performance. Introducing a H defect in the left UL region between the source and channel can drastically enhance the ON-state currents and reduce the SS to below 60 mV/decade. When the H defect is positioned far from the gate and/or at the center sites, the ON-state currents are substantially enhanced, meeting the International Technology Roadmap for Semiconductors requirements for high-performance and low-power devices with 5 nm channel length. The gate-all-around (GAA) structure can further improve the performance of the devices with H defects. Particularly for the devices with H defects near the edge, the GAA structure significantly reduces the SS values as low as 35 mV/decade. Our study demonstrates that GAA structure can greatly enhance the performance of the arsenene nanoribbon TFET devices with H defects, providing theoretical guidance for improving TFET performance based on two-dimensional material nanoribbons through the combination of defect engineering and GAA gate structures.