Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics

GeTe is highly sought-after due to its versatility as high-performance thermoelectrics, phase change materials, as well as ferroelectric Rashba semiconductor. Compared to most thermoelectric materials, it has an additional degree of freedom of rhombohedral-cubic phase transition at 673 K. At this te...

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Main Authors: Ady Suwardi, Cao, Jing, Hu, Lei, Wei, Fengxia, Wu, Jing, Zhao, Yunshan, Lim, Su Hui, Yang, Lan, Tan, Xian Yi, Chien, Sheau Wei, Yin, Yan, Zhou, Wu-Xing, Wong, Nancy Lai Mun, Wang, Xizu, Lim, Suo Hon, Ni, Xiping, Li, Dengfeng, Yan, Qingyu, Zheng, Yun, Zhang, Gang, Xu, Jianwei
Other Authors: School of Materials Science and Engineering
Format: Article
Language:English
Published: 2021
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Online Access:https://hdl.handle.net/10356/148448
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1484482023-07-14T16:03:26Z Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics Ady Suwardi Cao, Jing Hu, Lei Wei, Fengxia Wu, Jing Zhao, Yunshan Lim, Su Hui Yang, Lan Tan, Xian Yi Chien, Sheau Wei Yin, Yan Zhou, Wu-Xing Wong, Nancy Lai Mun Wang, Xizu Lim, Suo Hon Ni, Xiping Li, Dengfeng Yan, Qingyu Zheng, Yun Zhang, Gang Xu, Jianwei School of Materials Science and Engineering Engineering::Materials::Energy materials Thermoelectrics GeTe GeTe is highly sought-after due to its versatility as high-performance thermoelectrics, phase change materials, as well as ferroelectric Rashba semiconductor. Compared to most thermoelectric materials, it has an additional degree of freedom of rhombohedral-cubic phase transition at 673 K. At this temperature, the lattice thermal conductivity approaches theoretical minimum due to ferroelectric instability while the high-energy Σ and low-energy L bands converge to give outstanding electronic properties. Therefore, modulation of the phase transition temperature allows simultaneous and synergistic tuning of electronic and thermal transport properties to achieve high zT. In this work, Sn alloying together with Bi, Sb doping is used to suppress the phase transition to achieve a pure cubic structure with lattice thermal conductivity of around 0.4 W/mK and peak zT of 1.7 at 723 K with average zT of 1.23 between 400 and 800 K. Furthermore, Vickers hardness of 270, and Young’s modulus of 63.5 GPa in Ge0.4Sn0.4Bi0.02Sb0.12Te is by far the highest amongst binary chalcogenides. More importantly, the high quality factor achieved in this work enables ample room for further zT improvements. The fundamental insights drawn from this work provide a pathway towards engineering GeTe-based alloys to achieve high zT at any temperature of interest. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) Accepted version 2021-05-18T14:16:50Z 2021-05-18T14:16:50Z 2020 Journal Article Ady Suwardi, Cao, J., Hu, L., Wei, F., Wu, J., Zhao, Y., Lim, S. H., Yang, L., Tan, X. Y., Chien, S. W., Yin, Y., Zhou, W., Wong, N. L. M., Wang, X., Lim, S. H., Ni, X., Li, D., Yan, Q., Zheng, Y., ...Xu, J. (2020). Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics. Journal of Materials Chemistry A, 8, 18880-18890. https://dx.doi.org/10.1039/D0TA06013E 2050-7488 https://hdl.handle.net/10356/148448 10.1039/D0TA06013E 8 18880 18890 en Journal of Materials Chemistry A © 2020 Royal Society of Chemistry. All rights reserved. This paper was published in Journal of Materials Chemistry A and is made available with permission of Royal Society of Chemistry application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Materials::Energy materials
Thermoelectrics
GeTe
spellingShingle Engineering::Materials::Energy materials
Thermoelectrics
GeTe
Ady Suwardi
Cao, Jing
Hu, Lei
Wei, Fengxia
Wu, Jing
Zhao, Yunshan
Lim, Su Hui
Yang, Lan
Tan, Xian Yi
Chien, Sheau Wei
Yin, Yan
Zhou, Wu-Xing
Wong, Nancy Lai Mun
Wang, Xizu
Lim, Suo Hon
Ni, Xiping
Li, Dengfeng
Yan, Qingyu
Zheng, Yun
Zhang, Gang
Xu, Jianwei
Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics
description GeTe is highly sought-after due to its versatility as high-performance thermoelectrics, phase change materials, as well as ferroelectric Rashba semiconductor. Compared to most thermoelectric materials, it has an additional degree of freedom of rhombohedral-cubic phase transition at 673 K. At this temperature, the lattice thermal conductivity approaches theoretical minimum due to ferroelectric instability while the high-energy Σ and low-energy L bands converge to give outstanding electronic properties. Therefore, modulation of the phase transition temperature allows simultaneous and synergistic tuning of electronic and thermal transport properties to achieve high zT. In this work, Sn alloying together with Bi, Sb doping is used to suppress the phase transition to achieve a pure cubic structure with lattice thermal conductivity of around 0.4 W/mK and peak zT of 1.7 at 723 K with average zT of 1.23 between 400 and 800 K. Furthermore, Vickers hardness of 270, and Young’s modulus of 63.5 GPa in Ge0.4Sn0.4Bi0.02Sb0.12Te is by far the highest amongst binary chalcogenides. More importantly, the high quality factor achieved in this work enables ample room for further zT improvements. The fundamental insights drawn from this work provide a pathway towards engineering GeTe-based alloys to achieve high zT at any temperature of interest.
author2 School of Materials Science and Engineering
author_facet School of Materials Science and Engineering
Ady Suwardi
Cao, Jing
Hu, Lei
Wei, Fengxia
Wu, Jing
Zhao, Yunshan
Lim, Su Hui
Yang, Lan
Tan, Xian Yi
Chien, Sheau Wei
Yin, Yan
Zhou, Wu-Xing
Wong, Nancy Lai Mun
Wang, Xizu
Lim, Suo Hon
Ni, Xiping
Li, Dengfeng
Yan, Qingyu
Zheng, Yun
Zhang, Gang
Xu, Jianwei
format Article
author Ady Suwardi
Cao, Jing
Hu, Lei
Wei, Fengxia
Wu, Jing
Zhao, Yunshan
Lim, Su Hui
Yang, Lan
Tan, Xian Yi
Chien, Sheau Wei
Yin, Yan
Zhou, Wu-Xing
Wong, Nancy Lai Mun
Wang, Xizu
Lim, Suo Hon
Ni, Xiping
Li, Dengfeng
Yan, Qingyu
Zheng, Yun
Zhang, Gang
Xu, Jianwei
author_sort Ady Suwardi
title Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics
title_short Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics
title_full Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics
title_fullStr Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics
title_full_unstemmed Tailoring the phase transition temperature to achieve high-performance cubic GeTe-based thermoelectrics
title_sort tailoring the phase transition temperature to achieve high-performance cubic gete-based thermoelectrics
publishDate 2021
url https://hdl.handle.net/10356/148448
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