Phonon-limited mobility in n-type single-layer MoS2 from first principles

We study the phonon-limited mobility in intrinsic n-type single-layer MoS₂ for temperatures T>100 K. The materials properties including the electron-phonon interaction are calculated from first principles and the deformation potentials and Fröhlich interaction in single-layer MoS₂ are established. The calculated room-temperature mobility of ∼410 cm²V^-1s^-1 is found to be dominated by optical phonon scattering via intra and intervalley deformation potential couplings and the Fröhlich interaction. The mobility is weakly dependent on the carrier density and follows a μ∼T^-γ temperature dependence with γ=1.69 at room temperature. It is shown that a quenching of the characteristic homopolar mode, which is likely to occur in top-gated samples, increases the mobility with ∼70 cm²V^-1s^-1 and can be observed as a decrease in the exponent to γ=1.52. In comparison to recent experimental findings for the mobility in single-layer MoS₂ (∼200 cm²V^-1s^-1), our results indicate that mobilities close to the intrinsic phonon-limited mobility can be achieved in two-dimensional materials via dielectric engineering that effectively screens static Coulomb scattering on, e.g., charged impurities.