Comprehensive Analytical Model for Exploring the Dominant Scattering Mechanism of Two-Dimensional MoS₂ FETs

Abstract

This work proposes a comprehensive analytical model for two-dimensional molybdenum disulfide (MoS2) field-effect transistors (FETs). This model incorporates single-particle and transport relaxation times intended to investigate the dominant scattering mechanism in these devices. Our results show that in MoS2 FETs with a short channel length, there is a shift in short-range scattering from anisotropy mediated by the tunneling mechanism toward isotropy due to thermionic emission when the gate voltage is increased, which is in line with density functional theory (DFT). Meanwhile, long-range scattering by the interface traps electrons responsible for carrier transport in long-channel MoS2 FETs. We validate the model against experimental data on $I_{d}$ - $V_{d}$ and $I_{d}$ - $V_{g}$ characteristics, including mobility. The validations indicate that our model can accurately capture negative differential resistance (NDR) phenomenon and interface traps in MoS2 FETs. Therefore, our model is suitable to gain detailed insight into the dominant scattering mechanism directly from the current-voltage characteristics curve, minimizing the need for complex measurements and simulations.

Keywords

• Dominant scattering mechanism
• MoS₂ FETs
• negative drain resistance
• interface traps
• quantum relaxation time
• transport relaxation time