Phonon-Driven Electron Scattering and Magnetothermoelectric Effect in Two-Dimensional Tin Selenide

The bulk tin selenide (SnSe) is the best thermoelectric material currently with the highest figure-of-merit due to the strong phonon-phonon interactions. We investigate the effect of electron-phonon coupling (EPC) on the transport properties of two-dimensional (2D) SnSe sheet. We demonstrate that EPC plays a key role in the scattering rate where the constant relaxation time approximation is deficient. The EPC strength is especially large in contrast to that of pristine graphene. The scattering rate depends sensitively on the system temperatures and the carrier densities when the Fermi energy approaches the band edge. We also investigate the magnetothermoelectric effect of the 2D SnSe. It is found that at low temperatures there are enormous magnetoelectrical resistivity and magnetothermal resistivity above 500\%, suggesting the high potential for device applications. Our results agree reasonably well with the experimental data.