First-Principles Thermodynamic Theory of Seebeck Coefficients

TL;DR

This paper introduces a thermodynamic first-principles method to calculate Seebeck coefficients directly from electronic density of states, simplifying the process and enabling high-throughput thermoelectric material discovery.

Contribution

It presents a novel thermodynamic approach to compute Seebeck coefficients from first principles, bypassing traditional Boltzmann transport theory.

Findings

Successfully applied to PbTe and SnSe materials.

Dramatically simplifies Seebeck coefficient calculations.

Facilitates high-throughput thermoelectric material screening.

Abstract

Thermoelectric effects, measured by the Seebeck coefficients, refer to the phenomena in which a temperature difference or gradient imposed across a thermoelectric material induces an electrical potential difference or gradient, and vice versa, enabling the direct conversion of thermal and electric energies. All existing understanding and first-principles calculations of Seebeck coefficients have been based on the Boltzmann kinetic transport theory. Here we demonstrate that the Seebeck coefficient is a well-defined thermodynamic quantity that can be determined from the change in the chemical potential of electrons induced by the temperature change and thus can be efficiently computed solely based on the electronic density of states through first-principles calculations at different temperatures. The proposed approach is demonstrated using the prototype PbTe and SnSe thermoelectric materials. The proposed thermodynamic approach dramatically simplifies the calculations of Seebeck coefficients, making it possible to search for high performance thermoelectric materials using high-throughput first-principles calculations.