Effects of topological edge states on the thermoelectric properties of Bi nanoribbons

TL;DR

This study uses first-principles calculations to explore how topological edge states influence the thermoelectric properties of Bi nanoribbons, revealing potential for improved thermoelectric performance.

Contribution

It demonstrates that topological edge states dominate electronic transport in Bi nanoribbons, leading to high Seebeck coefficients and thermoelectric efficiency at room temperature.

Findings

Edge states dominate electronic transport due to higher conductivity.

Room temperature Seebeck coefficient exceeds 3.0 with proper tuning.

Topological edge states could enable industrial thermoelectric applications.

Abstract

Using first-principles calculations combined with Boltzmann transport theory, we investigate the effects of topological edge states on the thermoelectric properties of Bi nanoribbons. It is found that there is a competition between the edge and bulk contributions to the Seebeck coefficients. However, the electronic transport of the system is dominated by the edge states because of its much larger electrical conductivity. As a consequence, a room temperature value exceeding 3.0 could be achieved for both p- and n-type systems when the relaxation time ratio between the edge and the bulk states is tuned to be 1000. Our theoretical study suggests that the utilization of topological edge states might be a promising approach to cross the threshold of the industrial application of thermoelectricity.