Boosting the thermoelectric performance of n-type Bi2S3 by hierarchical structure manipulation and carrier density optimization

Ji, Wenting and Shi, Xiao-Lei ORCID: https://orcid.org/0000-0003-0905-2547 and Liu, Wei-Di and Yuan, Hualei and Zheng, Kun and Wan, Biao and Shen, Weixia and Zhang, Zhuangfei and Fang, Chao and Wang, Qianqian and Chen, Liangchao and Zhang, Yuewen and Jia, Xiaopeng and Chen, Zhi-Gang ORCID: https://orcid.org/0000-0002-9309-7993 (2021) Boosting the thermoelectric performance of n-type Bi2S3 by hierarchical structure manipulation and carrier density optimization. Nano Energy, 87:106171. ISSN 2211-2855


Abstract

Te-free Bi2S3-based thermoelectric materials show great potential for eco-friendly and industrial scale-up applications because of their high-abundance, low-cost, low-toxicity, and low-thermal-conductivity features. However, their low figure of merit, ZT limits their further applications. In this work, we report a high ZT of ~0.8 at ~760 K in n-type polycrystalline Bi2S3 by a combination of hierarchical structure manipulation and carrier density optimization. A step-by-step fabrication by using mechanical alloying, high-pressure and high-temperature treatment, spark plasma sintering, and annealing leads to unique micro/nanostructures in polycrystalline Bi2S3 including refined grains, high-density Bi-rich nanoprecipitates, significant lattice distortions, and nanopores that confirmed by comprehensive characterizations, which contribute to significantly suppressed lattice thermal conductivity of 0.41 W m-1 K-1 at ~760 K. A further 0.5 mol% CuCl2-doping triggers impurity band in the electronic structure of Bi2S3 and narrows the bandgap for optimizing the carrier concentration at ~1×1020 cm-3, confirmed by both experimental results and first-principles density functional theory calculations. The optimized carrier concentration and maintained low lattice thermal conductivity give rise to a high power factor of ~5.3 μW cm-1 K-2 and high ZT that ranks as a top value. This work provides a new route to achieve high thermoelectric performance in n-type polycrystalline Bi2S3.


Statistics for USQ ePrint 42009
Statistics for this ePrint Item
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: 24 May 2021 07:07
Last Modified: 18 Aug 2021 23:39
Uncontrolled Keywords: thermoelectric; Bi2S3; structure; doping; 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
Identification Number or DOI: https://doi.org/10.1016/j.nanoen.2021.106171
URI: http://eprints.usq.edu.au/id/eprint/42009

Actions (login required)

View Item Archive Repository Staff Only