Intrinsic electrical transport properties of monolayer silicene and MoS 2 from first principles

The electron-phonon interaction and related transport properties are investigated in monolayer silicene and MoS${}_{2}$ by using a density functional theory calculation combined with a full-band Monte Carlo analysis. In the case of silicene, the results illustrate that the out-of-plane acoustic phonon mode may play the dominant role unlike its close relative, graphene. The small energy of this phonon mode, originating from the weak $sp$${}^{2}$ $ensuremath{pi}$ bonding between Si atoms, contributes to the high scattering rate and significant degradation in electron transport. In MoS${}_{2}$, the longitudinal acoustic phonons show the strongest interaction with electrons. The key factor in this material appears to be the $Q$ valleys located between the $ensuremath{Gamma}$ and $K$ points in the first Brillouin zone as they introduce additional intervalley scattering. The analysis also reveals the potential impact of extrinsic screening by other carriers and/or adjacent materials. Finally, the effective deformation potential constants are extracted for all relevant intrinsic electron-phonon scattering processes in both materials.