Multipocket synergy towards high thermoelectric performance in topological semimetal TaAs<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39747059.
- Also identified by DOI 10.1038/s41467-024-55490-6 and PMC identifier 11696835.
- 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
Charge-carrier compensation in topological semimetals amplifies the Nernst signal and simultaneously degrades the Seebeck coefficient. In this study, we report the simultaneous achievement of both a large Nernst signal and an unsaturating magneto-Seebeck coefficient in a topological nodal-line semimetal TaAs<sub>2</sub> single crystal. The unique dual-high transverse and longitudinal thermopowers are attributed to multipocket synergy effects: the combination of a strong phonon-drag effect and the two overlapping highly dispersive conduction and valence bands with electron-hole compensation and high mobility, promising a large Nernst effect; the third Dirac band causes a large magneto-Seebeck effect. High transverse and longitudinal power factors of ~3100 and ~50 μW cm<sup>-1</sup> K<sup>-2</sup>, respectively, are achieved, surpassing those of other topological semimetals and mainstream semiconductors. Our study presents a feasible approach for optimizing the longitudinal and transverse thermopowers in topological semimetals simultaneously and demonstrates the potential of TaAs<sub>2</sub> for low temperature solid-state cooling.