Density Functional Theory of the Seebeck coefficient in the Coulomb blockade regime

TL;DR

This paper improves the theoretical calculation of the Seebeck coefficient in the Coulomb blockade regime by introducing a correction based on the temperature derivative of the exchange correlation potential, aligning well with experiments.

Contribution

It proposes a simple correction to density functional theory calculations to accurately evaluate the Seebeck coefficient in the Coulomb blockade regime.

Findings

Corrected DFT results match rate equation calculations.

The method aligns with experimental data on carbon nanotubes.

Enhances the predictive power of DFT for thermoelectric properties.

Abstract

The Seebeck coefficient plays a fundamental role in identifying the efficiency of a thermoelectric device. Its theoretical evaluation for atomistic models is routinely based on Density Functional Theory calculations combined with the Landauer-B\"uttiker approach to quantum transport. This combination, however, suffers from serious drawbacks for devices in the Coulomb blockade regime. We show how to cure the theory through a simple correction in terms of the {\em temperature derivative} of the exchange correlation potential. Our results compare well with both rate equations and experimental findings on carbon nanotubes.