Rashba effect maximizes thermoelectric performance of GeTe derivatives

Hong, Min and Lyv, Wanyu and Li, Meng and Xu, Shengduo and Sun, Qiang and Zou, Jin and Chen, Zhi-Gang ORCID: https://orcid.org/0000-0002-9309-7993 (2020) Rashba effect maximizes thermoelectric performance of GeTe derivatives. Joule, 4 (9). pp. 2030-2043. ISSN 2542-4351


Abstract

Advances in thermoelectrics are motivated by the innovation of thermoelectric theories. The Rashba effect, spin-dependent band splitting, paves a new path to enhance thermoelectric performance. Herein, we investigate the Rashba effect in GeTe, in which the rhombohedral distortion provides a unique handle to examine the mechanism of the Rashba effect for tuning thermoelectric properties. Fundamentally, we discover that the Rashba effect originates from the specific atomic site displacement. Experimentally, Sn-doped GeTe has a strong Rashba effect and yields an ultra-high power factor, meanwhile additional Sb alloying effectively tunes the carrier concentration. Moreover, microstructure characterizations reveal that the co-existence of grain boundaries, nanoprecipitates, and stacking faults significantly reinforces phonon scatterings and leads to an ultra-low lattice thermal conductivity. Finally, a high figure of merit is achieved in Ge1−x−ySnxSbyTe. The demonstrated benchmark figure of merit originated from the Rashba effect can provide a promising arena for enhancing thermoelectric performance in wide materials.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version in accordance with the copyright policy of the publisher.
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 21 Jan 2021 03:30
Last Modified: 29 Jan 2021 04:34
Uncontrolled Keywords: thermoelectric energy conversion; GeTe-based alloys; Rashba spin-dependent band splitting; spin-orbital coupling; band structure engineering; stacking faults
Fields of Research (2008): 02 Physical Sciences > 0204 Condensed Matter Physics > 020404 Electronic and Magnetic Properties of Condensed Matter; Superconductivity
09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401605 Functional materials
51 PHYSICAL SCIENCES > 5104 Condensed matter physics > 510404 Electronic and magnetic properties of condensed matter; superconductivity
Funding Details:
Identification Number or DOI: https://doi.org/10.1016/j.joule.2020.07.021
URI: http://eprints.usq.edu.au/id/eprint/40550

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