Large thermoelectric power factors by opening the band gap in semimetallic Heusler alloys
- Author(s)
- Fabian Garmroudi, Michael Parzer, Alexander Riss, Simon Beyer, Sergii Khmelevskyi, Takao Mori, Michele Reticcioli, Ernst Bauer
- Abstract
Efficient thermoelectric devices are typically built from semiconducting materials since their band gap leads to an asymmetry in the continuum of energy-dependent charge transport necessary for a large Seebeck effect. Due to their low cost and excellent mechanical properties half- and full-Heusler compounds have emerged as promising candidates for various applications. Here, we demonstrate how the thermopower of semimetallic Fe2VAl-based Heusler alloys can be significantly increased by transferring electronic states from within the pseudogap to higher energies. Density functional theory calculations predict that partial Ti and Si co-substitution in Fe2V1−xTixAl1−ySiy drives an opening of the pseudogap, that can be likewise achieved in Fe2V1−xTaxAl1−ySiy. Consequently, our experimental measurements on these co-substituted systems reveal exceptionally large thermoelectric power factors (7.3 − 10.3 mWm−1K−2 near room temperature), as well as average power factors up to 4.6 mWm−1K−2 in the most pratical temperature range (293 − 573 K). With this work we set the course for a general and reliable way of boosting the thermoelectric performance of semimetallic Heusler alloys.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- Technische Universität Wien, Research and Services Division of Materials Data and Integrated System, University of Tsukuba
- Journal
- Materials Today Physics
- Volume
- 27
- No. of pages
- 7
- DOI
- https://doi.org/10.1016/j.mtphys.2022.100742
- Publication date
- 10-2022
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103009 Solid state physics
- ASJC Scopus subject areas
- Materials Science(all), Energy (miscellaneous), Physics and Astronomy (miscellaneous)
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/large-thermoelectric-power-factors-by-opening-the-band-gap-in-semimetallic-heusler-alloys(1ace7ca1-5392-4865-ba7e-469844097aaa).html