Kinetic condition driven phase and vacancy enhancing thermoelectric performance of low-cost and eco-friendly Cu2-xS

Liu, Wei-Di and Shi, Xiao-Lei ORCID: https://orcid.org/0000-0003-0905-2547 and Gao, Han and Moshwan, Raza and Xu, Sheng-Duo and Wang, Yuan and Yang, Lei and Chen, Zhi-Gang and Zou, Jin (2019) Kinetic condition driven phase and vacancy enhancing thermoelectric performance of low-cost and eco-friendly Cu2-xS. Journal of Materials Chemistry C, 7. pp. 5366-5373. ISSN 2050-7526


Abstract

Low-cost and eco-friendly Cu2S has attracted wide research interest in recent years. Here, we synthesized Cu2-xS via a facile solvothermal method. Thermoelectric performance of as-sintered Cu2-xS can be easily tuned via kinetic-condition control due to subsequently changed phase contents. Based on detailed characterization, it is found that reducing the NaOH amount can preferentially boost the formation tetragonal Cu1.96S and monoclinic Cu1.94S phases instead of monoclinic Cu2S phase. This phase content change can promote the formation of Cu vacancies in the high-temperature cubic Cu2-xS after the phase transition at ~700 K. The enhanced Cu vacancy levels can both effectively enhance the power factor (S2σ) and figure of merit (zT) due to simultaneously optimized hole concentration (nH) and reduced phase transition temperature. A peak zT of ~1.1 is achieved in the Cu2-xS synthesized with 2 ml NaOH with an average composition of Cu1.95S. The average zT of as high as ~0.76 (T = 573~833 K) is obtained due to both optimized nH leading to enhanced S2σ and reduced phase transition temperature (at ~700 K).


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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 02:08
Last Modified: 13 Mar 2020 06:35
Fields of Research : 09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Identification Number or DOI: 10.1039/c9tc00819e
URI: http://eprints.usq.edu.au/id/eprint/37931

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