Prediction of Semiconducting 2D Nanofilms of Janus WSi₂P₂As₂ for Applications in Sub-5 nm Field-Effect Transistors

Searching for eligible two-dimensional (2D) semiconductors to fabricate high-performance (HP) short-channel field-effect transistors (FETs) at the nanoscale is essential toward the continuous miniaturization of devices. Herein, we predict the 2D Janus WSi 2 P 2 As 2 semiconductor and propose it as a qualified channel material for sub-5 nm FETs by using first-principles calculations. The results demonstrate that the monolayer Janus WSi 2 P 2 As 2 is a 2D semiconducting nanofilm with a band gap of 0.83 eV, a hole mobility of 490 cm 2 V –1 s –1 in the armchair direction, and an out-of-plane polarization. Benefiting from these outstanding intrinsic characteristics, the performance of the 5 and 3 nm gate-length WSi 2 P 2 As 2 FETs can fulfill the International Technology Roadmap for Semiconductors for HP standards after employing optimizing strategies, including underlap structure, dielectric project, and cold source. Our results promote the development of new 2D nanomaterials and device architectures for designing HP short-channel FETs.