Realizing high figure of merit in heavy-band p-type half-Heusler thermoelectric materials.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 26330371.
- Also identified by DOI 10.1038/ncomms9144 and PMC identifier 4569725.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Solid-state thermoelectric technology offers a promising solution for converting waste heat to useful electrical power. Both high operating temperature and high figure of merit zT are desirable for high-efficiency thermoelectric power generation. Here we report a high zT of ∼1.5 at 1,200 K for the p-type FeNbSb heavy-band half-Heusler alloys. High content of heavier Hf dopant simultaneously optimizes the electrical power factor and suppresses thermal conductivity. Both the enhanced point-defect and electron-phonon scatterings contribute to a significant reduction in the lattice thermal conductivity. An eight couple prototype thermoelectric module exhibits a high conversion efficiency of 6.2% and a high power density of 2.2 W cm(-2) at a temperature difference of 655 K. These findings highlight the optimization strategy for heavy-band thermoelectric materials and demonstrate a realistic prospect of high-temperature thermoelectric modules based on half-Heusler alloys with low cost, excellent mechanical robustness and stability.