Leveraging bipolar effect to enhance transverse thermoelectricity in semimetal Mg<sub>2</sub>Pb for cryogenic heat pumping.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34158499.
- Also identified by DOI 10.1038/s41467-021-24161-1 and PMC identifier 8219662.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Toward high-performance thermoelectric energy conversion, the electrons and holes must work jointly like two wheels of a cart: if not longitudinally, then transversely. The bipolar effect - the main performance restriction in the traditional longitudinal thermoelectricity, can be manipulated to be a performance enhancer in the transverse thermoelectricity. Here, we demonstrate this idea in semimetal Mg<sub>2</sub>Pb. At 30 K, a giant transverse thermoelectric power factor as high as 400 μWcm<sup>-1</sup>K<sup>-2</sup> is achieved, a 3 orders-of-magnitude enhancement than the longitudinal configuration. The resultant specific heat pumping power is ~ 1 Wg<sup>-1</sup>, higher than those of existing techniques at 10~100 K. A large number of semimetals and narrow-gap semiconductors making poor longitudinal thermoelectrics due to severe bipolar effect are thus revived to fill the conspicuous gap of thermoelectric materials for solid-state applications.