Enhancing thermoelectric performance of Bi2Te3-based nanostructures through rational structure design

Abstract

Nanostructuring has been successfully employed to enhance the thermoelectric performance of Bi₂Te₃ due to its obtained low thermal conductivity. In order to further reduce the thermal conductivity, we designed a hierarchical nanostructure assembled with well-aligned Bi₂Te₃ nanoplates using Te nanotubes as templates by a facile microwave-assisted solvothermal synthesis. From the comparisons of their thermoelectric performance and theoretical calculations with simple Bi₂Te₃ nanostructures, we found that Te/Bi₂Te₃ hierarchical nanostructures exhibit a higher figure-of-merit due to the optimized reduced Fermi level and enhanced phonon scattering, as well as the suppressed bipolar conduction. This study provides an effective approach to enhance the thermoelectric performance of Bi₂Te₃-based nanostructures by rationally designing the nanostructures.