Transport properties of electrically sintered bismuth antimony telluride with antimony nanoprecipitation

Enhanced carrier mobility and reduced lattice thermal conductivity are essential for high-performance thermoelectric materials. In this letter, the influences of current-induced grain-boundary modification and nanoprecipitation on electrical and thermal transport properties of bismuth antimony telluride (BST) are investigated. With the passage of a high-density pulsed current (similar to 10(3) A/cm(2)), the electrically sintered BST exhibits a two-time enhancement in carrier mobility while maintaining a low lattice thermal conductivity compared to the hot-pressed BST. The modified transport properties are attributed to the reduced carrier scattering at grain boundaries and the increased phonon scattering by Sb nanoprecipitates in the electrically sintered BST. A numerical estimation based on the modified Callaway's model is provided to reveal the impact of nonoprecipitates on phonon transport in BST. Published by AIP Publishing.