Improved figure of merit (z) at low temperatures for superior thermoelectric cooling in Mg3(Bi,Sb)2

Autor: Nan Chen, Hangtian Zhu, Guodong Li, Zhen Fan, Xiaofan Zhang, Jiawei Yang, Tianbo Lu, Qiulin Liu, Xiaowei Wu, Yuan Yao, Youguo Shi, Huaizhou Zhao
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Nature Communications, Vol 14, Iss 1, Pp 1-9 (2023)
Druh dokumentu: article
ISSN: 2041-1723
DOI: 10.1038/s41467-023-40648-5
Popis: Abstract The low-temperature thermoelectric performance of Bi-rich n-type Mg3(Bi,Sb)2 was limited by the electron transport scattering at grain boundaries, while removing grain boundaries and bulk crystal growth of Mg-based Zintl phases are challenging due to the volatilities of elemental reactants and their severe corrosions to crucibles at elevated temperatures. Herein, for the first time, we reported a facile growth of coarse-grained Mg3Bi2-x Sb x crystals with an average grain size of ~800 μm, leading to a high carrier mobility of 210 cm2 · V−1 · s−1 and a high z of 2.9 × 10−3 K−1 at 300 K. A $$\Delta$$ Δ T of 68 K at T h of 300 K, and a power generation efficiency of 5.8% below 450 K have been demonstrated for Mg3Bi1.5Sb0.5- and Mg3Bi1.25Sb0.75-based thermoelectric modules, respectively, which represent the cutting-edge advances in the near-room temperature thermoelectrics. In addition, the developed grain growth approach can be potentially extended to broad Zintl phases and other Mg-based alloys and compounds.
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