Thermoelectric properties of quaternary chalcogenide Cu₂ZnSnS₄ synthesised by mechanical alloying

ABSTRACT

The quaternary chalcogenide Cu₂ZnSnS₄ has emerged as a potential thermoelectric (TE) material due to its low thermal conductivity (κ), high Seebeck coefficient (S) and composition including earth-abundant, low-cost and non-toxic elements. In this work, Cu₂ZnSnS₄ was synthesised from a mixture of Cu, Zn, Sn and S powders using a mechanical alloying method. As a result, Cu₂ZnSnS₄ powders were formed after 16 h of milling, without additional heat treatment. After milling, the powders were heat-treated at 723 K for 24 h and then sintered by spark plasma sintering under an applied pressure of 60 MPa at 873 K for 10 min. The heat-treated Cu₂ZnSnS₄ sample showed a wide-band-gap of 1.49 eV. The sintered Cu₂ZnSnS₄ sample exhibited S and κ values of 170 μV K⁻¹ and 1.06 W m⁻¹ K⁻¹, respectively with an electrical conductivity σ of 1240 S m⁻¹ and a dimensionless figure of merit (ZT) of 0.022 at 663 K.

KEYWORDS:

• Quaternary chalcogenide
• thermoelectric materials
• thermoelectric properties
• mechanical alloying
• powder metallurgy

Acknowledgements

This work is supported by National Foundation for Science and Technology Development (Nafosted), Vietnam [grant number 103.02-2016.18]. We are thankful to Professor Michitaka Ohtaki and Dr Suekuni Koichiro from the Kyushu University, Japan for supporting thermoelectric properties measurements.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes on contributors

Dr. Bui Duc Long received his Engineering degree in Materials Engineering from Hanoi University of Science and Technology (HUST), Vietnam in 2004. Then, he went to the Universiti Sains Malaysia (USM) and Toyohashi University of Technology studied for his doctoral degree. He received his doctoral degree in February, 2011 and was awarded Fellowships from the USM in 2011, and the Royal Institute of Technology (KTH) in 2012. At KTH, he worked on thermoelectric materials. He joined the University of Malaya as the senior lecturer in 2013, and moved to HUST in 2016. Currently, his research interested is focusing on thermoelectric materials and metal matrix composites.

Mr. Nguyen Van Khanh graduated from School of Materials Science and Engineering, Hanoi University of Science and Technology in 2018. His research interested is on the synthesis of materials for thermoelectric applications.

Dr. Duong Ngoc Binh graduated as an engineer from Hanoi University of Science and Technology (HUST) in 2003. In 2010, he received his PhD degree in the field of materials engineering from Universiti Sains Malaysia. His research interests include light metals and alloys, metal recycling, synthesizing of new alloys, composites etc. He is currently working at the School of Materials Science and Engineering, HUST.

Dr. Nguyen Hong Hai received the Engineering degree in materials and foundry technology from Hanoi University of Science and Technology (HUST), Vietnam, in 2004. He received the Ph.D degree in metallurgical engineering from Technical University of Ostrava, Czech Republic, in 2013. His research interests include light metals, exothermic materials as well as discrete materials. Dr. Hai currently serves as Head of Department of Materials and Foundry Technology, School of Materials Science and Engineering, HUST.

Additional information

Funding

This work was supported by National Foundation for Science and Technology Development [grant number 103.02-2016.18].