Rational band engineering and structural manipulations inducing high thermoelectric performance in n-type CoSb3 thin films

Zheng, Zhuang-Hao and Shi, Xiao-Lei ORCID: https://orcid.org/0000-0003-0905-2547 and Ao, Dong-Wei and Liu, Wei-Di and Chen, Yue-Xing and Li, Fu and Chen, Shuo and Tian, Xiao-Qing and Li, Xin-Ru and Duan, Jing-Yi and Ma, Hong-Li and Zhang, Xiang-Hua and Liang, Guang-Xing and Fan, Ping and Chen, Zhi-Gang ORCID: https://orcid.org/0000-0002-9309-7993 (2021) Rational band engineering and structural manipulations inducing high thermoelectric performance in n-type CoSb3 thin films. Nano Energy, 81:105683. pp. 1-12. ISSN 2211-2855


Abstract

Owing to the earth-abundancy, eco-friendliness and high thermoelectric performance, CoSb3 skutterudites have been employed in thermoelectric devices with a high energy conversion efficiency. However, the thermoelectric performance of CoSb3-based thin films is still relatively low within the medium temperature range. In this work, we report a record high ZT of ~0.65 at 623 K in the n-type Ag/In co-doped CoSb3 thin films, fabricated by a facile magnetron sputtering technique. Extensive characterizations and computational results indicate both Ag and In as fillers prefer to occupy the interstitial sites in the CoSb3 lattice. A 0.2% Ag doping induces impurity states in the band structure of CoSb3, boosts the density-of-states near the Fermi level and enhances the absolute Seebeck coefficient up to ~198 μV K−1. Simultaneously, a 4.2% In doping further tunes the bandgap, increases the electrical conductivity up to ~75 S cm−1, and contributes to an optimized power factor of ~2.94 μW cm−1 K−2 at 623 K. In addition, these interstitial dopants accompanying with dense grain boundaries contribute an ultra-low thermal conductivity of ~0.28 W m−1 K−1 at 623 K, leading to a high ZT in the film system. This work demonstrates that rational band engineering and structural manipulations can achieve high performance in n-type CoSb3-based thin films, which possess full potential for applying to miniature thermoelectric devices.


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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: 06 Jan 2021 04:01
Last Modified: 06 Jan 2021 04:23
Uncontrolled Keywords: Thermoelectric; CoSb3; Thin film; Doping; Characterization; Calculation
Fields of Research (2008): 09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401605 Functional materials
Socio-Economic Objectives (2008): B Economic Development > 85 Energy > 8507 Energy Conservation and Efficiency > 850799 Energy Conservation and Efficiency not elsewhere classified
Socio-Economic Objectives (2020): 17 ENERGY > 1701 Energy efficiency > 170199 Energy efficiency not elsewhere classified
Identification Number or DOI: https://doi.org/10.1016/j.nanoen.2020.105683
URI: http://eprints.usq.edu.au/id/eprint/40383

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