Phonon-Limited Electron Mobility in Single-Layer MoS₂

The dynamics of electron transport in single-layer MoS₂ is simulated by employing the single particle Monte Carlo method. Acoustic phonon scattering, optical phonon scattering and Fr?hlich scattering are taken into account. It is found that the electron mobility decreases from 806 cm²/V?s for a transverse electrical field of 10³ V/m to 426/112 cm²/V?s for a transverse electrical field of 10⁵/10⁷ V/m. Further detailed analysis on carrier dynamics reveals that the low field mobility is dominated by the acoustic phonon scattering while the role of optical phonon scattering is to relax the electron energy below the optical phonon energy by efficient energy relaxation through optical phonon emission. Only when the transverse electrical field is larger than 10⁶ V/m, the mobility can be determined by the optical phonon scattering, leading to a strong mobility degradation.