We study the phonon-limited mobility in intrinsic $n$-type single-layer MoS${}_2$ 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 MoS${}_2$ are established. The calculated room-temperature mobility of $\sim$410 cm${}^2$V${}^{-1}$s${}^{-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 $\mu \sim T^{-\gamma }$ temperature dependence with $\gamma =1.69$ 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 $\sim$70 cm${}^2$V${}^{-1}$s${}^{-1}$ and can be observed as a decrease in the exponent to $\gamma =1.52$. In comparison to recent experimental findings for the mobility in single-layer MoS${}_2$ ($\sim$200 cm${}^2$V${}^{-1}$s${}^{-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.

• Received 14 October 2011

DOI:https://doi.org/10.1103/PhysRevB.85.115317