High thermoelectric performance in metallic NiAu alloys via interband scattering.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37713496.
- Also identified by DOI 10.1126/sciadv.adj1611 and PMC identifier 10881022.
- 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
Thermoelectric materials seamlessly convert thermal into electrical energy, making them promising for power generation and cooling applications. Although historically the thermoelectric effect was first discovered in metals, state-of-the-art research focuses on semiconductors. Here, we discover unprecedented thermoelectric performance in metals and realize ultrahigh power factors up to 34 mW m<sup>-1</sup> K<sup>-2</sup> in binary Ni<i><sub>x</sub></i>Au<sub>1-<i>x</i></sub> alloys, more than twice larger than in any bulk material above room temperature, reaching <i>zT</i><sub>max</sub> ∼ 0.5. In metallic Ni<i><sub>x</sub></i>Au<sub>1-<i>x</i></sub> alloys, large Seebeck coefficients originate from electron-hole selective scattering of Au <i>s</i> electrons into more localized Ni <i>d</i> states. This intrinsic energy filtering effect owing to the unique band structure yields a strongly energy-dependent carrier mobility. While the metastable nature of the Ni-Au system as well as the high cost of Au pose some constraints for practical applications, our work challenges the common belief that good metals are bad thermoelectrics and presents an auspicious route toward high thermoelectric performance exploiting interband scattering.