Intrinsic carrier mobility of multi-layered MoS${}_2$ field-effect transistors on SiO${}_2$

Abstract

By fabricating and characterizing multi-layered MoS${}_2$-based field-effect transistors (FETs) in a four terminal configuration, we demonstrate that the two terminal-configurations tend to underestimate the carrier mobility $\hat{I}¼$ due to the Schottky barriers at the contacts. For a back-gated two-terminal configuration we observe mobilities as high as 125 cm${}^2$V${}^{-1}$s${}^{-1}$ which is considerably smaller than 306.5 cm${}^2$V${}^{-1}$s${}^{-1}$ as extracted from the same device when using a four-terminal configuration. This indicates that the intrinsic mobility of MoS${}_2$ on SiO${}_2$ is significantly larger than the values previously reported, and provides a quantitative method to evaluate the charge transport through the contacts.

8 pages, 5 figures, typos fixed, and references updated