Intrinsic carrier mobility of multi-layered MoS2 field-effect transistors on SiO2

Abstract

By fabricating and characterizing multi-layered MoS2-based field-effect transistors in a four terminal configuration, we demonstrate that the two terminal-configurations tend to underestimate the carrier mobility μ due to the Schottky barriers at the contacts. For a back-gated two-terminal configuration, we observe mobilities as high as 91 cm2 V−1 s−1 which is considerably smaller than 306.5 cm2 V−1 s−1 as extracted from the same device when using a four-terminal configuration. This indicates that the intrinsic mobility of MoS2 on SiO2 is significantly larger than the values previously reported, and provides a quantitative method to evaluate the charge transport through the contacts.