Electron-phonon-averaged approximation for first-principles computations of electron relaxation times and transport properties in semiconductor materials

TL;DR

This paper introduces a simplified approximation for electron-phonon scattering rates to efficiently evaluate electronic transport properties in semiconductors, aiding high-throughput thermoelectric material screening.

Contribution

It proposes a new approximation method for electron-phonon scattering that is computationally efficient and validated on half-Heusler compounds.

Findings

Agreement with experimental transport data

Deviations from Wiedemann-Franz law at high temperatures

Effective for high-throughput material screening

Abstract

We present a simple and efficient approximation to the electron-phonon scattering rate suitable for high-throughput screening of candidate materials for thermoelectric devices, based on electronic transport. The method is applied to calculate the electronic transport coefficients of half-Heusler compounds, showing agreement with experimental data. By directly computing electrical and the electronic part of the thermal conductivities, we find deviations from the Wiedemann-Franz law in these compounds at high temperatures and low carrier concentrations.