To gain insight into the peculiar temperature dependence of the thermoelectric material SnSe, we employ many-body perturbation theory and explore the influence of the electron-phonon interaction on its electronic and transport properties. We show that a lattice dynamics characterized by soft highly-polar phonons induces a large thermal enhancement of the Fr\"ohlich interaction. We account for these phenomena in ab-initio calculations of the photoemission spectrum and electrical conductivity at finite temperature, unraveling the mechanisms behind recent experimental data. Our results reveal a complex interplay between lattice thermal expansion and Fr\"ohlich coupling, providing a new rationale for the in-silico prediction of transport coefficients of high-performance thermoelectrics.
@article{arxiv.1905.09174,
title = {Thermally-Enhanced Fr\"ohlich Coupling in SnSe},
author = {Fabio Caruso and Maria Troppenz and Santiago Rigamonti and Claudia Draxl},
journal= {arXiv preprint arXiv:1905.09174},
year = {2019}
}