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NaCdSb: An Orthorhombic Zintl Phase with Exceptional Intrinsic Thermoelectric Performance |
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| Authors: | Kai Guo Yuting Zhang Song Yuan Qinghang Tang Chen Lin Pengfei Luo Jiong Yang Shusheng Pan Li-Dong Zhao Guofeng Cheng Jiye Zhang Jun Luo |
| Institution: | 1. School of Physics and Materials Science, Guangzhou University, Guangzhou, 510006 China;2. School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444 China
Contribution: Data curation (equal), Investigation (equal), Validation (lead);3. School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444 China Contribution: Data curation (lead), Formal analysis (equal);4. Materials Genome Institute, Shanghai University, 99 Shangda Road, Shanghai, 200444 China Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072 China Contribution: Investigation (equal);5. School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444 China Contribution: Investigation (equal), Methodology (supporting);6. School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444 China Contribution: Investigation (equal);7. Materials Genome Institute, Shanghai University, 99 Shangda Road, Shanghai, 200444 China Contribution: Investigation (equal);8. School of Physics and Materials Science, Guangzhou University, Guangzhou, 510006 China Research Center for Advanced Information Materials (CAIM), Huangpu Research & Graduate School of Guangzhou University, Sino-Singapore Guangzhou Knowledge City Huangpu District, Guangzhou, 510555 China Contribution: Investigation (equal), Writing - review & editing (supporting);9. School of Materials Science and Engineering, Beihang University, Beijing, 100191 China;10. Analysis & Testing Center for Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 China Contribution: Formal analysis (equal), Investigation (supporting);11. School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444 China Contribution: Data curation (equal), Writing - review & editing (supporting);12. School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444 China |
| Abstract: | Many Zintl phases are promising thermoelectric materials owning to their features like narrow band gaps, multiband behaviors, ideal charge transport tunnels, and loosely bound cations. Herein we show a new Zintl phase NaCdSb with exceptional intrinsic thermoelectric performance. Pristine NaCdSb exhibits semiconductor behaviors with an experimental hole concentration of 2.9×1018 cm−3 and a calculated band gap of 0.5 eV. As the temperature increases, the hole concentration rises gradually and approaches its optimal one, leading to a high power factor of 11.56 μW cm−1 K−2 at 673 K. The ultralow thermal conductivity is derived from the small phonon group velocity and short phonon lifetime, ascribed to the structural anharmonicity of Cd−Sb bonds. As a consequence, a maximum zT of 1.3 at 673 K has been achieved without any doping optimization or structural modification, demonstrating that NaCdSb is a remarkable thermoelectric compound with great potential for performance improvement. |
| Keywords: | Electron-Crystal NaCdSb Phonon-Glass Thermoelectric Properties Zintl Phase |