Effects of Defects on Thermoelectric Properties of Carbon Nanotubes

TL;DR

This study provides a theoretical analysis of how defects like vacancies and Stone-Wales defects impair the thermoelectric performance of carbon nanotubes by reducing electrical conductance and overall efficiency.

Contribution

It offers new insights into the impact of specific defects on CNT thermoelectric properties and emphasizes the importance of defect control for device optimization.

Findings

Defects strongly suppress electron conductance in CNTs.

Defects deteriorate the thermoelectric performance of individual CNTs.

Defects significantly degrade the thermoelectric efficiency of CNT networks.

Abstract

Carbon nanotubes (CNTs) have recently attracted attention as materials for flexible thermoelectric devices. To provide theoretical guideline of how defects influence the thermoelectric performance of CNTs, we theoretically studied the effects of defects (vacancies and Stone-Wales defects) on its thermoelectric properties; thermal conductance, electrical conductance, and Seebeck coefficient. The results revealed that the defects mostly strongly suppresses the electron conductance, and deteriorates the thermoelectric performance of a CNT. By plugging in the results and the intertube-junction properties into the network model, we further show that the defects with realistic concentrations can significantly degrade the thermoelectric performance of CNT-based networks. Our findings indicate the importance of the purification of CNTs for improving CNT-based thermoelectrics.