April 22 - 26, 2024
Seattle, Washington
May 7 - 9, 2024 (Virtual)

Event Supporters

2024 MRS Spring Meeting
EN08.12.03

Are Topological Insulators Promising Thermoelectrics?

When and Where

Apr 26, 2024
9:30am - 9:45am
Room 336, Level 3, Summit

Presenter(s)

Co-Author(s)

Michael Toriyama1,Jeff Snyder1

Northwestern University1

Abstract

Michael Toriyama1,Jeff Snyder1

Northwestern University1
Some of the best thermoelectric (TE) materials to date are also topological insulators (TIs). While many studies have investigated the effects of topologically-protected surface states on TE properties, it is still unclear how the bulk band structure of a TI can benefit the TE performance. Here, we perform high-throughput transport calculations using density functional theory (DFT) to reveal that TIs, when properly optimized, tend to outperform normal insulators as TEs. Models based on Boltzmann transport theory show that warping driven by band inversion, a key characteristic of TIs, is beneficial for TE performance because of reduced transport mass and effectively higher valley degeneracy. The model also reveals that the band inversion strength is a critical material property dictating the TE performance, where TIs with strongly inverted bands exhibit higher <i>zT</i>. We suggest potential avenues for tuning the band inversion strength and, as a result, enhancing the TE performance in TIs, such as alloying and strain engineering. The study marks TIs as serious candidates for TE applications owing to band inversion-driven warping.

Keywords

quantum materials | thermoelectricity

Symposium Organizers

Ernst Bauer, Vienna Univ of Technology
Jan-Willem Bos, University of St. Andrews
Marisol Martin-Gonzalez, Inst de Micro y Nanotecnologia
Alexandra Zevalkink, Michigan State University

Session Chairs

Ernst Bauer
Kornelius Nielsch

In this Session