Impact of Gate-Induced Mobility Attenuation on Accurate Characterization of Perovskite Field Effect Transistors

Halide perovskites have recently gained attention as promising semiconducting materials for field-effect transistors (FETs), offering potential for low-cost, easily fabricable, and high-mobility devices. However, accurately extracting key device characteristics, such as carrier mobility and contact resistance, remains challenging due to limitations of conventional current-voltage models, as well as due to the absence of standardized extraction procedures. Furthermore, gate-induced mobility attenuation, which represents mobility reduction under high gate field, is often overlooked despite its potential significance in perovskite channels. Here, we experimentally verify gate-induced mobility attenuation in perovskite FETs and study refined extraction methods that explicitly incorporate this effect. Four-probe measurements directly unveil that mobility decreases at high overdrive voltages, consistent with the analytical form of gate-induced attenuation. Applying this framework to experimental data reveals that neglecting gate-induced mobility attenuation can result in up to 10-fold overestimation of contact resistance and a 2-fold underestimation of mobility. Pulsed measurements with suppressed ion migration effect further confirm that gate-induced mobility attenuation continues to occur, and the degree of overestimation and underestimation of device characteristics remains almost the same regardless of ion migration effect. A comparative study with MoS2 FETs also confirms the general applicability of our approach, establishing an accurate methodology for FET device characterization.