High thermoelectric performance in p-type polycrystalline Cd-doped SnSe achieved by a combination of cation vacancies and localized lattice engineering

Shi, Xiaolei and Wu, Angyin and Feng, Tianli and Zheng, Kun and Liu, Weidi and Sun, Qiang and Hong, Min and Pantelides, Sokrates T. and Chen, Zhi-Gang and Zou, Jin (2019) High thermoelectric performance in p-type polycrystalline Cd-doped SnSe achieved by a combination of cation vacancies and localized lattice engineering. Advanced Energy Materials, 9 (11 - Article 180352). pp. 1-15. ISSN 1614-6832

Abstract

Herein, a high figure of merit (ZT) of ≈1.7 at 823 K is reported in p‐type polycrystalline Cd‐doped SnSe by combining cation vacancies and localized‐lattice engineering. It is observed that the introduction of Cd atoms in SnSe lattice induce Sn vacancies, which act as p‐type dopants. A combination of facile solvothermal synthesis and fast spark plasma sintering technique boosts the Sn vacancy to a high level of ≈2.9%, which results in an optimum hole concentration of ≈2.6 × 1019 cm−3 and an improved power factor of ≈6.9 µW cm−1 K−2. Simultaneously, a low thermal conductivity of ≈0.33 W m−1 K−1 is achieved by effective phonon scattering at localized crystal imperfections, as observed by detailed structural characterizations. Density functional theory calculations reveal that the role of Cd atoms in the SnSe lattice is to reduce the formation energy of Sn vacancies, which in turn lower the Fermi level down into the valence bands, generating holes. This work explores the fundamental Cd‐doping mechanisms at the nanoscale in a SnSe matrix and demonstrates vacancy and localized‐lattice engineering as an effective approach to boosting thermoelectric performance. The work provides an avenue in achieving high‐performance thermoelectric properties of materials.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published version cannot be displayed due to copyright restrictions.
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: 27 Sep 2019 05:20
Last Modified: 30 Sep 2019 00:22
Uncontrolled Keywords: Cd-doping; characterization; solvothermal; thermoelectric; tin selenide
Fields of Research : 09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Funding Details:
Identification Number or DOI: 10.1002/aenm.201803242
URI: http://eprints.usq.edu.au/id/eprint/36059

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