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

TL;DR

This study explores how electron-phonon interactions influence transport and thermoelectric properties in 2D tin selenide, revealing significant scattering effects and potential for magnetic field-controlled thermoelectric devices.

Contribution

It provides the first detailed analysis of electron-phonon coupling effects on transport and magnetothermoelectric properties in 2D SnSe, highlighting their importance beyond traditional approximations.

Findings

EPC significantly affects scattering rates in 2D SnSe.

Magnetothermoelectric resistivity exceeds 500% at low temperatures.

Results align well with experimental observations.

Abstract

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.