Structural Modularization of Cu2 Te Leading to High Thermoelectric Performance near the Mott-Ioffe-Regel Limit

Kunpeng Zhao; Chenxi Zhu; Min Zhu; Hongyi Chen; Jingdan Lei; Qingyong Ren; Tian-Ran Wei; Pengfei Qiu; Fangfang Xu; Lidong Chen; Jian He; Xun Shi

doi:10.1002/adma.202108573

Structural Modularization of Cu₂ Te Leading to High Thermoelectric Performance near the Mott-Ioffe-Regel Limit

Adv Mater. 2022 May;34(19):e2108573. doi: 10.1002/adma.202108573. Epub 2022 Apr 8.

Authors

Kunpeng Zhao^{1

2}, Chenxi Zhu³, Min Zhu⁴, Hongyi Chen⁵, Jingdan Lei¹, Qingyong Ren⁶, Tian-Ran Wei^{1

2}, Pengfei Qiu³, Fangfang Xu³, Lidong Chen³, Jian He⁷, Xun Shi^{1

3}

Affiliations

¹ State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
² Wuzhen Laboratory, Tongxiang, 314500, China.
³ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, China.
⁴ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.
⁵ College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China.
⁶ China Spallation Neutron Source, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
⁷ Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634-0978, USA.

PMID: 35293020
DOI: 10.1002/adma.202108573

Abstract

To date, thermoelectric materials research stays focused on optimizing the material's band edge details and disfavors low mobility. Here, the paradigm is shifted from the band edge to the mobility edge, exploring high thermoelectricity near the border of band conduction and hopping. Through coalloying iodine and sulfur, the plain crystal structure is modularized of liquid-like thermoelectric material Cu₂ Te with mosaic nanograins and the highly size mismatched S/Te sublattice that chemically quenches the Cu sublattice and drives the electronic states from itinerant to localized. A state-of-the-art figure of merit of 1.4 is obtained at 850 K for Cu₂ (S_0.4 I_0.1 Te_0.5 ); and remarkably, it is achieved near the Mott-Ioffe-Regel limit unlike mainstream thermoelectric materials that are band conductors. Broadly, pairing structural modularization with the high performance near the Mott-Ioffe-Regel limit paves an important new path towards the rational design of high-performance thermoelectric materials.

Keywords: copper telluride; structural modularization; the Mott-Ioffe-Regel limit; thermoelectric.

Abstract

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