Efros-Shklovskii variable range hopping and nonlinear transport in 1T/1T${}^{\mathrm{\prime }}$-MoS${}_2$

We have studied temperature- and electric-field dependent carrier transport in single flakes of MoS${}_2$ treated with n-butyllithium. The temperature dependence of the four-terminal resistance follows the Efros-Shklovskii variable range hopping conduction mechanism. From measurements in the Ohmic and non-Ohmic regime, we estimate the localization length and the average hopping length of the carriers, as well as the effective dielectric constant. Furthermore, comparison between two- and four-probe measurements yield a contact resistance that increases significantly with decreasing temperature.