Beyond monolayers: four-layer MoS 2 as the key to next-generation transistors

Abstract This work presents a comprehensive thickness- and channel-length-dependent analysis of MoS 2 MOSFETs using a combined COMSOL drift–diffusion and Python-based NEGF quantum-transport framework. Monolayer, bilayer, four-layer, six-layer, and bulk MoS 2 channels were evaluated across 50–100 nm lengths to capture the coupled effects of quantum confinement, interlayer screening, and short-channel electrostatics. The results reveal strongly thickness-dependent behaviour: monolayer devices offer excellent gate control but limited current drive; bilayer devices improve mobility with moderate electrostatics; six-layer and bulk channels show degraded control with high SS and positive DIBL. Significantly, four-layer MoS 2 consistently outperforms all other configurations, exhibiting the lowest SS (≈62–82 mV/dec), highest g m , maximum intrinsic gain, and robust negative DIBL across all channel lengths. Electrostatic and charge-centroid analysis confirms that four layers achieve the optimal balance between gate coupling and screening. These results establish four-layer MoS 2 as the most promising configuration for high-performance and low-power 2D MOSFET design.