High thermoelectric performance enabled by convergence of nested conduction bands in Pb₇Bi₄Se₁₃ with low thermal conductivity.

ABSTRACT: Thermoelectrics enable waste heat recovery, holding promises in relieving energy and environmental crisis. Lillianite materials have been long-term ignored due to low thermoelectric efficiency. Herein we report the discovery of superior thermoelectric performance in Pb₇Bi₄Se₁₃ based lillianites, with a peak figure of merit, zT of 1.35 at 800 K and a high average zT of 0.92 (450-800 K). A unique quality factor is established to predict and evaluate thermoelectric performances. It considers both band nonparabolicity and band gaps, commonly negligible in conventional quality factors. Such appealing performance is attributed to the convergence of effectively nested conduction bands, providing a high number of valley degeneracy, and a low thermal conductivity, s

SUBMITTER: Hu L 

PROVIDER: S-EPMC8352968 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature