Investigation of Carrier Transport Mechanism in p-Type Tungsten Diselenide Field-Effect Transistors

Abstract

In this study, we investigate the carrier transport mechanism in p-type tungsten diselenide (WSe2) field-effect transistors (FETs) over a wide range of operation regimes and temperatures. By using temperature-dependent field-effect conductance measurements, the variable range hopping and the multiple trapping and release are considered as dominant carrier transport mechanisms in the WSe2 FET at low and high temperatures, respectively, in the sub-threshold region. In the above-threshold region, the intrinsic field-effect mobility (mu(FEi)) decreases with an increase in temperature for temperatures above -75 degrees C (198 K). This suggests that phonon scattering is the dominant physical mechanism that limits mu(FEi) in the p-type WSe2 FET, in the above-threshold region, at real operating temperatures above room temperature.