Electron–phonon scattering limited hole mobility at room temperature in a MoS2 monolayer: first-principles calculations

Abstract

Based on first-principles calculations and iterative solution of the Boltzmann transport equation, we theoretically study the room temperature mobility (RTM) of a valence band hole in a MoS₂ monolayer (ML) limited by electron–phonon (e–ph) scattering. The hole mobility obtained by us is 26.0 cm² V⁻¹ s⁻¹ at 300 K. This is a value much closer to the experimental result (about 40.0 cm² V⁻¹ s⁻¹). In contrast, the semi-empirical estimate based on the deformational potential (DP) model in previous literature gave a value of 200.5 cm² V⁻¹ s⁻¹, far away from the experimental data. By a detailed analysis, we find that unlike the case of conduction band electrons, the intervalley scattering realized by longitudinal acoustic (LA) phonons plays a dominant role in influencing the hole mobility. And this is the main reason for the DP model failing to give a quantitative estimate of the hole RTM in MoS₂-ML.