Globally Optimal Band Structure for Thermoelectrics in Realistic Systems

TL;DR

This paper proposes that a linear dispersion with specific transport gaps can theoretically optimize thermoelectric performance by maximizing the figure of merit, offering insights into ideal band structures for real systems.

Contribution

It introduces a theoretical model identifying a globally optimal band structure with linear dispersion and transport gaps for thermoelectrics, advancing understanding of ideal electronic properties.

Findings

Linear dispersion under acoustic phonon scattering leads to a constant charge transport distribution.

A band structure with two transport gaps and optimized bandwidth is theoretically optimal.

This model suggests real systems could exhibit such ideal band structures.

Abstract

Observation is made that a linear dispersion in any dimension under acoustic-phonon-deformation-potential scattering theoretically prescribes a constant charge transport distribution, required for the boxcar profile known to maximize the thermoelectric figure of merit. A linear dispersion squeezed by two transport gaps for optimized bandwidth under scattering by phonon deformation then theoretically constitutes a globally optimal qualitative band structure that may arise in real systems.