Intrinsic electronic transport and thermoelectric power factor in n-type doped monolayer MoS2

The electronic transport and thermoelectric properties in n-type doped monolayer MoS2 are investigated by a parameter-free method based on first-principles calculations, electron-phonon coupling (EPC), and Boltzmann transport equation (BTE). Remarkably, the calculated electron mobility mu similar to 47 cm(2) V-1 s(-1) and thermoelectric power factor sigma S-2 similar to 2.93 x 10(-3) W m(-1) K-2 at room temperature are much lower than the previous theoretical values (e.g. mu similar to 130-410 cm(2) V-1 s(-1) and sigma S-2 similar to 2.80 x 10(-3) W m(-1) K-2), but agree well with the most recent experimental findings of mu similar to 37 cm(2) V-1 s(-1) and sigma S-2 similar to 3.00 x 10(-3) W m(-1) K-2 Wm(-1) K-2. The EPC projections on phonon dispersion and the phonon branch dependent scattering rates indicate that the acoustic phonons, especially the longitudinal acoustic phonons, dominate the carrier scattering. Therefore, a mobility of 68 cm(2) V-1 s(-1) is achieved if only the acoustic phonons induced scattering is included, in accordance with the result of 72 cm(2) V-1 s(-1) estimated from the deformation potential driven by acoustic modes. Furthermore, via excluding the scattering from the out-of-plane modes to simulate the EPC suppression, the obtained mobility of 258 cm(2) V-1 s(-1) is right in the range of 200-700 cm(2) V-1 s(-1) measured in the samples with top deposited dielectric layer. In addition, we also compute the lattice thermal conductivity K-L of monolayer MoS2 using phonon BTE, and obtain K-L similar to 123 W m(-1) K-1 at 300 K.