In-situ observation of the continuous phase transition in determining the high thermoelectric performance of polycrystalline Sn0.98Se

Dargusch, Matthew and Shi, Xiao-Lei ORCID: https://orcid.org/0000-0003-0905-2547 and Tran, Xuan Quy and Feng, Tianli and Somidin, Flora and Tan, Xin and Liu, Weidi and Jack, Kevin and Venezuela, Jeffrey and Maeno, Hiroshi and Toriyama, Takaaki and Matsumura, Syo and Pantelides, Sokrates T. and Chen, Zhi-Gang (2019) In-situ observation of the continuous phase transition in determining the high thermoelectric performance of polycrystalline Sn0.98Se. Journal of Physical Chemistry Letters, 10 (21). pp. 6512-6517.


Abstract

We report a comprehensive in-situ phase-change study on polycrystalline Sn0.98Se via high-temperature X-ray diffraction and in-situ high-voltage transmission electron microscopy from room temperature to 843 K. The results clearly demonstrate a continuous phase transition from Pnma to Cmcm starting from 573 to 843 K, rather than a sudden transition at 800 K. We also find that the thermal-conductivity rise at high temperature after the phase transition, as commonly seen in pristine SnSe, does not occur in Sn0.98Se, leading to a high thermoelectric figure of merit. Density functional theory calculations reveal the origin to be the suppression of bipolar thermal conduction in the Cmcm phase of Sn0.98Se due to the enlarged bandgap. This work fills the gap of in-situ characterization on polycrystalline Sn0.98Se and provides new insights into the outstanding thermoelectric performance of polycrystalline Sn0.98Se.


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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: 09 Mar 2020 05:24
Last Modified: 13 Mar 2020 06:50
Fields of Research : 09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Identification Number or DOI: 10.1021/acs.jpclett.9b02818
URI: http://eprints.usq.edu.au/id/eprint/37944

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