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Significant Enhancement of Thermoelectric Figure of Merit in BiSbTe-Based Composites by Incorporating Carbon Microfiber |
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| Authors: | Guangsai Yang Lina Sang Frank Fei Yun David R G Mitchell Gilberto Casillas Ning Ye Khay See Jun Pei Xungai Wang Jing-Feng Li G Jeffrey Snyder Xiaolin Wang |
| Affiliation: | 1. Institute for Superconducting and Electronic Materials, Australian, Institute for Innovative Materials, University of Wollongong, North Wollongong, NSW, 2500 Australia
Australian Research Council Centre of Excellence in Future Low-Energy Electronics Technologies, University of Wollongong, North Wollongong, NSW, 2500 Australia;2. Electron Microscopy Centre, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong, NSW, 2500 Australia;3. Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002 P. R. China;4. Institute for Superconducting and Electronic Materials, Australian, Institute for Innovative Materials, University of Wollongong, North Wollongong, NSW, 2500 Australia;5. State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084 P. R. China;6. Institute for Frontier Materials (IFM), Deakin University, Geelong, Victoria, 3216 Australia;7. Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208 USA |
| Abstract: | Bismuth telluride-based materials are already being commercially developed for thermoelectric (TE) cooling devices and power generators. However, the relatively low efficiency, which is characterized by a TE figure of merit, zT, is the main obstacle to more widespread application. Significant advances in the TE performance have been made through boundary engineering via embedding nanoinclusions or nanoscale grains. Herein, an effective approach to greatly enhance the TE performance of p-type BiSbTe material by incorporating carbon microfibers is reported. A high zT of 1.4 at 375 K and high average zT of 1.25 for temperatures in the range of 300 to 500 K is achieved in the BiSbTe/carbon microfiber (BST/CF) composite materials. Their superior TE performance originates from the low thermal conductivity and the relatively high power factor. A TE unicouple device based on the p-type BST/CF composite material and the commercially available n-type bismuth telluride-based material shows a huge cooling temperature drop in the operating temperature range of 299–375 K, and is greatly superior to the unicouple device made of both commercial p-type and n-type bismuth telluride-based material. The materials demonstrate a high average zT and excellent mechanical properties and are strong candidates for practical applications. |
| Keywords: | Bi 0 5Sb 1 5Te 3 carbon microfibers cooling performance high zT thermoelectric materials |