In-situ growth of high-performance (Ag, Sn) co-doped CoSb3 thermoelectric thin films

Zheng, Zhuang-Hao and Niu, Jun-Yun and Ao, Dong-Wei and Jabar, Bushra and Shi, Xiao-Lei ORCID: https://orcid.org/0000-0003-0905-2547 and Li, Xin-Ru and Li, Fu and Liang, Guang-Xing and Chen, Yue-Xing and Chen, Zhi-Gang ORCID: https://orcid.org/0000-0002-9309-7993 and Fan, Ping (2021) In-situ growth of high-performance (Ag, Sn) co-doped CoSb3 thermoelectric thin films. Journal of Materials Science & Technology, 92. pp. 178-185. ISSN 1005-0302

Text (Submitted Version) 20210409- reivsed manuscript JMST final-2.pdf Restricted

Abstract

Owing to the unique features, such as mechanically robust, low-toxic, high stability, and high thermoelectric performance, CoSb3-based skutterudite materials are among art-of-the state thermoelectric candidates. In this work, we develop a facile in-situ method for the growth of well-crystallinity (Ag, Sn) co-doped CoSb3 thin films. This preparation method can efficiently control the dopant concentration and distribution in the thin films. Both the density functional theory calculation and the experimental results suggest that Sn and Ag dopants trend to enter the lattice and preferentially fill interstitial sites. Additionally, band structure calculation results suggest that the Fermi level moves into the conduction bands due to co-doping and eventually induces the increased electrical conductivity, which agrees with the optimization of carrier concentration. Moreover, an increase in the density of state after co-doping is responsible for the increased Seebeck coefficient. As a result, the power factors of (Ag, Sn) co-doped CoSb3 thin films are greatly enhanced, and the maximum power factor achieves over 0.3 mW m−1 K−2 at 623 K, which is almost two times than that of the un-doped CoSb3 film. Multiple microstructures, including Sb vacancies and Ag/Sn interstitial atoms as point defects, and a high density of lattice distortions coupled with nano-sized Ag-rich grains, lead to all scale phonon scatterings. As a result, a reduced thermal conductivity of ∼0.28 W m−1 K−1 and a maximum ZT of ∼0.52 at 623 K are obtained from (Ag, Sn) co-doped CoSb3 thin films. This study indicates our facile in-situ growth can be used to develop high-performance dual doped CoSb3 thins.

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Item Type:	Article (Commonwealth Reporting Category C)
Refereed:	Yes
Item Status:	Live Archive
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:	10 May 2021 02:53
Last Modified:	12 Oct 2021 03:05
Uncontrolled Keywords:	CoSb3 thin films; Thermoelectric; Magnetron sputtering; Co-doping
Fields of Research (2008):	09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Fields of Research (2020):	40 ENGINEERING > 4016 Materials engineering > 401605 Functional materials
Identification Number or DOI:	https://doi.org/10.1016/j.jmst.2021.04.007
URI:	http://eprints.usq.edu.au/id/eprint/41947

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