Theory of enhancement of thermoelectric properties of materials with nanoinclusions

TL;DR

This paper develops a theoretical model showing how metallic nanoinclusions can enhance thermoelectric efficiency by increasing the Seebeck coefficient and reducing thermal conductivity through energy filtering and phonon scattering.

Contribution

It introduces a new theory linking nanoinclusion-induced band bending to improved thermoelectric properties, considering both electron and phonon scattering effects.

Findings

Seebeck coefficient can be significantly increased by energy-dependent scattering.

Enhancement of ZT is more pronounced at high doping levels due to electron scattering.

At low doping, ZT improvement mainly results from reduced phonon thermal conductivity.

Abstract

Based on the concept of band bending at metal/semiconductor interfaces as an energy filter for electrons, we present a theory for the enhancement of the thermoelectric properties of semiconductor materials with metallic nanoinclusions. We show that the Seebeck coefficient can be significantly increased due to a strongly energy-dependent electronic scattering time. By including phonon scattering, we find that the enhancement of ZT due to electron scattering is important for high doping, while at low doping it is primarily due to a decrease in the phonon thermal conductivity.