High-Performance Ballistic Quantum Transport of Sub-10 nm Monolayer GeS Field-Effect Transistors

As a mature two-dimensional (2D) semiconductor, GeS has attracted huge interest due to its potential for wide applications in optical and electrical devices. However, research on the quantum transport of monolayer (ML) GeS field-effect transistors (FETs) is still lacking so far. In this work, we comprehensively reveal the ballistic transport performance and gate control mechanism of sub-10 nm ML GeS metal–oxide–semiconductor FETs (MOSFETs) by ab initio quantum transport simulation, including on-state current, subthreshold swing, intrinsic delay time, and power consumption. The on-state current of GeS p-MOSFETs (Lg = 4.0–8.8 nm) along the armchair direction distinctly exceeds the high-performance requirements of the 2013 International Technology Roadmap for Semiconductors, and the p-devices along the zigzag direction perform well in the low-power applications. Encouragingly, by adopting underlap structures, the ballistic transport performance of GeS MOSFETs can be further developed until the gate length decreases to 2.0 nm. Furthermore, compared with the previous typical 2D semiconductor MOSFETs, ML GeS MOSFETs exhibit superior competitiveness with short-channel length. We infer that the GeS monolayer will become a promising candidate for the short-channel material of transistors.