Dependence of Tunneling Mechanism on Two-Dimensional Material Parameters: A High-Throughput Study

A band-to-band tunneling FET (TFET) with an atomical two-dimensional (2D) channel is a potential candidate for the next-generation electronic device in view of its steep subthreshold swing and low power consumption. However, how to establish a precise physical model between the band property of 2D channel materials and the device performance of 2D TFETs is the key to accelerate their practical applications. Herein, through high-throughput first-principles calculations, we study the tunneling transport properties of 44 representative 2D materials with four kinds of crystal system. Particularly, we propose a well-defined and striking exponential scaling law $(\mathrm{SS}=A{\mathrm{e}}^{B{m}_{r}}+C)$ between the subthreshold swings (SSs) and reduced effective masses $({m}_{r})$ of 10-nm TFETs. According to the exponential model, 2D orthorhombic and trigonal crystal TFETs with the steep SS hold the reduced effective masses of more than 0.1 and $0.2\phantom{\rule{0.25em}{0ex}}{m}_{0}$, which could inhibit tunneling leakage current. These insights provide guidance for material screening in the construction of post-Moore 2D low-power transistors.