Semiclassical Electron and Phonon Transport from First Principles: Application to Layered Thermoelectrics

TL;DR

This paper reviews first-principles computational methods for designing and optimizing thermoelectric materials, focusing on electronic and phononic transport, with application to layered tin and germanium selenides.

Contribution

It provides a comprehensive overview of first-principles approaches for thermoelectric property prediction and demonstrates their application to layered thermoelectric materials.

Findings

Accurate assessment of thermoelectric properties via simulations

Application to layered tin and germanium selenides

Guidelines for computational design of thermoelectrics

Abstract

Thermoelectrics are a promising class of materials for renewable energy owing to their capability to generate electricity from waste heat, with their performance being governed by a competition between charge and thermal transport. A detailed understanding of energy transport at the nanoscale is thus of paramount importance for developing efficient thermoelectrics. Here, we provide a comprehensive overview of the methodologies adopted for the computational design and optimization of thermoelectric materials from first-principles calculations. First, we introduce density-functional theory, the fundamental tool to describe the electronic and vibrational properties of solids. Next, we review charge and thermal transport in the semiclassical framework of the Boltzmann transport equation, with a particular emphasis on the various scattering mechanisms between phonons, electrons, and impurities. Finally, we illustrate how these approaches can be deployed in determining the figure of merit of tin and germanium selenides, an emerging family of layered thermoelectrics that exhibits a promising figure of merit. Overall, this review article offers practical guidelines to achieve an accurate assessment of the thermoelectric properties of materials by means of computer simulations.