Effects of the Dielectric Environment on Electronic Transport in Monolayer MoS2: Screening and Remote Phonon Scattering

We investigate theoretically the impact of the dielectric environment on electronic transport in monolayer MoS2. In particular, we extend our first-principles Monte Carlo method to account for the screening of the electron-phonon interaction by the free carriers in the layer and the dielectric environment. In addition, we include the effect of remote-phonon scattering induced by the surrounding dielectrics. For monolayer MoS2 on various dielectric substrates, we find that screening could improve the mobility significantly, but the inclusion of remote-phonon scattering degrades the mobility below its free-standing value. In our model, the introduction of gates in a dual-gate configuration does not appreciably decrease the remote-phonon interaction as it does in inversion layers or thicker films. However, for a double-gate field-effect transistor, we still obtain reasonable transport characteristics.