A Physical Model for the Hysteresis in MoS2 Transistors

Even though the hysteresis in the gate transfer characteristics of two-dimensional (2D) transistors is a frequently encountered phenomenon, the physics behind it are up to now only barely understood, let alone modeled. Here, we demonstrate that the hysteresis phenomenon can be captured accurately by a previously established non-radiative multiphonon model describing charge capture and emission events in the surrounding dielectrics. The charge transfer model is embedded into a drift-diffusion based TCAD simulation environment, which was adapted to 2D devices. Our modeling setup was validated against measurement data on a back-gated single-layer MoS₂ transistor with SiO₂ as a gate dielectric. We use the modeling approach to gain a thorough understanding of the hysteresis, which will help to control this problem in future devices.