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 Frohlich interaction in single-layer MoS2 are established.

The calculated room-temperature mobility of similar to 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 Frohlich interaction. The mobility is weakly dependent on the carrier density and follows a mu similar to 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 similar to 70 cm(2)V(-1)s(-1) and can be observed as a decrease in the exponent to. = 1.52. In comparison to recent experimental findings for the mobility in single-layer MoS2 (similar to 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.