Holey topological thermoelectrics

TL;DR

This paper investigates how introducing many holes into three-dimensional topological insulators enhances thermoelectric efficiency by leveraging surface conduction and reduced phonon thermal conductivity, with tunable properties via external fields.

Contribution

It demonstrates that holey topological insulators can achieve high thermoelectric figure of merit ZT, surpassing unity, due to surface states and phonon suppression, with tunable efficiency.

Findings

High ZT values achievable with holey structures

Surface states contribute significantly to thermoelectric performance

Efficiency can be tuned with external magnetic fields or tunneling

Abstract

We study the thermoelectric properties of three-dimensional topological insulators with many holes (or pores) in the bulk. We show that at high density of these holes the thermoelectric figure of merit ZT can be large due to the contribution of the conducting surfaces and the suppressed phonon thermal conductivity. The maximum efficiency can be tuned by an induced gap in the surface states dispersion through tunneling or external magnetic fields. The large values of ZT, much higher than unity for reasonable parameters, make this system a strong candidate for applications in heat management of nanodevices, especially at low temperatures.