First-principles study of intrinsic mobilities in monolayer TMDs with two-dimensional Fröhlich interaction

In previous first-principles calculations of two-dimensional (2D) polar materials, the Fröhlich interaction has not been considered due to the lack of effective treatment to isolate the layers. By introducing the truncated Coulomb interactions into Wannier function interpolation, we successfully capture the converged long-range coupling of longitudinal optical (LO) phonons and calculate the intrinsic mobilities of 2H-monolayer TMDs. For MoS₂ and WS₂, the decrease caused by polar effect is small as the dominant scattering is from longitudinal acoustic (LA) phonons, while for MoSe₂, MoTe₂ and WSe₂, the decrease is large due to the comparable contribution from LO phonons. The WS₂ has the largest mobilities, while the MoTe₂ has the smallest mobilities which are much smaller than previous estimations. The mode dependent analysis shows the mean free paths are smaller than 20 nm at room temperature.