Liquid‐Phase Hot Deformation to Enhance Thermoelectric Performance of n‐type Bismuth‐Telluride‐Based Solid Solutions
Abstract Bismuth‐telluride‐based solid solutions are the best commercial thermoelectric materials near room temperature. For their n‐type polycrystalline compounds, the maximum figures of merit (zTs) are often less than 1.0 due to the degraded carrier mobility resulting from the loss of texture. Her...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2019-11-01
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| Series: | Advanced Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/advs.201901702 |
| _version_ | 1819023297349681152 |
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| author | Yehao Wu Yuan Yu Qi Zhang Tiejun Zhu Renshuang Zhai Xinbing Zhao |
| author_facet | Yehao Wu Yuan Yu Qi Zhang Tiejun Zhu Renshuang Zhai Xinbing Zhao |
| author_sort | Yehao Wu |
| collection | DOAJ |
| description | Abstract Bismuth‐telluride‐based solid solutions are the best commercial thermoelectric materials near room temperature. For their n‐type polycrystalline compounds, the maximum figures of merit (zTs) are often less than 1.0 due to the degraded carrier mobility resulting from the loss of texture. Herein, a liquid‐phase hot deformation procedure, during which the Bi2(Te,Se)3 ingots are directly hot deformed with the extrusion of liquid eutectic phase, is performed to enhance the thermoelectric performance of n‐type Bi2(Te,Se)3 alloys. The deformation‐induced dynamic recrystallization is remarkably suppressed due to the reduction of nucleation sites and the release of deformation stress by liquid phase, contributing to a weakened carrier scattering and enhanced carrier mobility. The liquid eutectic phase also facilitates the rotation of grains and enhanced (000l) texture, further improving carrier mobility. In addition, the dense dislocations and lattice distortion introduced into the matrix reduce the lattice thermal conductivity. As a result, a high zT value of 1.1 at 400 K is obtained, about 75% increment over the normal one‐step hot deformed alloys. This work not only demonstrates a simple and efficient technique for achieving superior n‐type Bi2Te3‐based materials, but also elucidates the important role of liquid eutectic phase in hot deformation. |
| first_indexed | 2024-12-21T04:36:39Z |
| format | Article |
| id | doaj.art-d4c879f8f58d48fe87184bb782db4553 |
| institution | Directory Open Access Journal |
| issn | 2198-3844 |
| language | English |
| last_indexed | 2024-12-21T04:36:39Z |
| publishDate | 2019-11-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advanced Science |
| spelling | doaj.art-d4c879f8f58d48fe87184bb782db45532022-12-21T19:15:50ZengWileyAdvanced Science2198-38442019-11-01621n/an/a10.1002/advs.201901702Liquid‐Phase Hot Deformation to Enhance Thermoelectric Performance of n‐type Bismuth‐Telluride‐Based Solid SolutionsYehao Wu0Yuan Yu1Qi Zhang2Tiejun Zhu3Renshuang Zhai4Xinbing Zhao5State Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang University Hangzhou 310027 ChinaI. Physikalisches Institut (IA) RWTH Aachen University 52074 Aachen GermanyState Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang University Hangzhou 310027 ChinaState Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang University Hangzhou 310027 ChinaState Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang University Hangzhou 310027 ChinaState Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang University Hangzhou 310027 ChinaAbstract Bismuth‐telluride‐based solid solutions are the best commercial thermoelectric materials near room temperature. For their n‐type polycrystalline compounds, the maximum figures of merit (zTs) are often less than 1.0 due to the degraded carrier mobility resulting from the loss of texture. Herein, a liquid‐phase hot deformation procedure, during which the Bi2(Te,Se)3 ingots are directly hot deformed with the extrusion of liquid eutectic phase, is performed to enhance the thermoelectric performance of n‐type Bi2(Te,Se)3 alloys. The deformation‐induced dynamic recrystallization is remarkably suppressed due to the reduction of nucleation sites and the release of deformation stress by liquid phase, contributing to a weakened carrier scattering and enhanced carrier mobility. The liquid eutectic phase also facilitates the rotation of grains and enhanced (000l) texture, further improving carrier mobility. In addition, the dense dislocations and lattice distortion introduced into the matrix reduce the lattice thermal conductivity. As a result, a high zT value of 1.1 at 400 K is obtained, about 75% increment over the normal one‐step hot deformed alloys. This work not only demonstrates a simple and efficient technique for achieving superior n‐type Bi2Te3‐based materials, but also elucidates the important role of liquid eutectic phase in hot deformation.https://doi.org/10.1002/advs.201901702bismuth tellurideshot deformationthermoelectric materialsthermoelectric properties |
| spellingShingle | Yehao Wu Yuan Yu Qi Zhang Tiejun Zhu Renshuang Zhai Xinbing Zhao Liquid‐Phase Hot Deformation to Enhance Thermoelectric Performance of n‐type Bismuth‐Telluride‐Based Solid Solutions Advanced Science bismuth tellurides hot deformation thermoelectric materials thermoelectric properties |
| title | Liquid‐Phase Hot Deformation to Enhance Thermoelectric Performance of n‐type Bismuth‐Telluride‐Based Solid Solutions |
| title_full | Liquid‐Phase Hot Deformation to Enhance Thermoelectric Performance of n‐type Bismuth‐Telluride‐Based Solid Solutions |
| title_fullStr | Liquid‐Phase Hot Deformation to Enhance Thermoelectric Performance of n‐type Bismuth‐Telluride‐Based Solid Solutions |
| title_full_unstemmed | Liquid‐Phase Hot Deformation to Enhance Thermoelectric Performance of n‐type Bismuth‐Telluride‐Based Solid Solutions |
| title_short | Liquid‐Phase Hot Deformation to Enhance Thermoelectric Performance of n‐type Bismuth‐Telluride‐Based Solid Solutions |
| title_sort | liquid phase hot deformation to enhance thermoelectric performance of n type bismuth telluride based solid solutions |
| topic | bismuth tellurides hot deformation thermoelectric materials thermoelectric properties |
| url | https://doi.org/10.1002/advs.201901702 |
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