Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor

Bi2Si2Te6, a 2D compound, is a direct band gap semiconductor with an optical band gap of 0.25 eV, and is a promising thermoelec-tric material. Single-phase Bi2Si2Te6 is prepared by a scalable ball-milling and annealing process and the highly densified polycrys-talline samples are prepared by spark p...

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Main Authors: Luo, Yubo, Ma, Zheng, Hao, Shiqiang, Cai, Songting, Luo, Zhong-Zhen, Wolverton, Christopher, Dravid, Vinayak P., Yang, Junyou, Yan, Qingyu, Kanatzidis, Mercouri G.
Other Authors: School of Materials Science and Engineering
Format: Journal Article
Language:English
Published: 2022
Subjects:
Online Access:https://hdl.handle.net/10356/159223
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author Luo, Yubo
Ma, Zheng
Hao, Shiqiang
Cai, Songting
Luo, Zhong-Zhen
Wolverton, Christopher
Dravid, Vinayak P.
Yang, Junyou
Yan, Qingyu
Kanatzidis, Mercouri G.
author2 School of Materials Science and Engineering
author_facet School of Materials Science and Engineering
Luo, Yubo
Ma, Zheng
Hao, Shiqiang
Cai, Songting
Luo, Zhong-Zhen
Wolverton, Christopher
Dravid, Vinayak P.
Yang, Junyou
Yan, Qingyu
Kanatzidis, Mercouri G.
author_sort Luo, Yubo
collection NTU
description Bi2Si2Te6, a 2D compound, is a direct band gap semiconductor with an optical band gap of 0.25 eV, and is a promising thermoelec-tric material. Single-phase Bi2Si2Te6 is prepared by a scalable ball-milling and annealing process and the highly densified polycrys-talline samples are prepared by spark plasma sintering. Bi2Si2Te6 shows a p-type semiconductor transport behavior and exhibits an intrinsically low lattice thermal conductivity of ~0.48 Wm-1K-1 (cross-plane) at 573 K. The first-principles density functional theory calculations indicate that such low lattice thermal conductivity is derived from the interactions between acoustic phonons and low-lying optical phonons, local vibrations of Bi, the low Debye temperature and strong anharmonicity result from the unique 2D crystal structure and metavalent bonding of Bi2Si2Te6. The Bi2Si2Te6 exhibits an optimal figure of merit ZT of ~0.51 at 623 K, which can be further enhanced by the substitution of Bi with Pb. Pb doping leads to a large increase in power factor S2σ, from ~4.0 μWcm-1K-2 of Bi2Si2Te6 to ~8.0 μWcm-1K-2 of Bi1.98Pb0.02Si2Te6 at 775 K, owing to the increase in carrier concentration. Moreover, Pb doping in-duces a further reduction in the lattice thermal conductivity to ~0.38 Wm-1K-1 (cross-plane) at 623 K in Bi1.98Pb0.02Si2Te6, due to strengthened point defect (PbBi’) scattering. The simultaneous optimization of the power factor and lattice thermal conductivity achieves a peak ZT of ~0.90 at 723 K and a high average ZT of ~0.66 at 400–773 K in Bi1.98Pb0.02Si2Te6.
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spelling ntu-10356/1592232023-07-14T16:05:30Z Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor Luo, Yubo Ma, Zheng Hao, Shiqiang Cai, Songting Luo, Zhong-Zhen Wolverton, Christopher Dravid, Vinayak P. Yang, Junyou Yan, Qingyu Kanatzidis, Mercouri G. School of Materials Science and Engineering Science::Chemistry::Inorganic chemistry Engineering::Materials Thermal Conductivity Bi₂Si₂Te₆ Bi2Si2Te6, a 2D compound, is a direct band gap semiconductor with an optical band gap of 0.25 eV, and is a promising thermoelec-tric material. Single-phase Bi2Si2Te6 is prepared by a scalable ball-milling and annealing process and the highly densified polycrys-talline samples are prepared by spark plasma sintering. Bi2Si2Te6 shows a p-type semiconductor transport behavior and exhibits an intrinsically low lattice thermal conductivity of ~0.48 Wm-1K-1 (cross-plane) at 573 K. The first-principles density functional theory calculations indicate that such low lattice thermal conductivity is derived from the interactions between acoustic phonons and low-lying optical phonons, local vibrations of Bi, the low Debye temperature and strong anharmonicity result from the unique 2D crystal structure and metavalent bonding of Bi2Si2Te6. The Bi2Si2Te6 exhibits an optimal figure of merit ZT of ~0.51 at 623 K, which can be further enhanced by the substitution of Bi with Pb. Pb doping leads to a large increase in power factor S2σ, from ~4.0 μWcm-1K-2 of Bi2Si2Te6 to ~8.0 μWcm-1K-2 of Bi1.98Pb0.02Si2Te6 at 775 K, owing to the increase in carrier concentration. Moreover, Pb doping in-duces a further reduction in the lattice thermal conductivity to ~0.38 Wm-1K-1 (cross-plane) at 623 K in Bi1.98Pb0.02Si2Te6, due to strengthened point defect (PbBi’) scattering. The simultaneous optimization of the power factor and lattice thermal conductivity achieves a peak ZT of ~0.90 at 723 K and a high average ZT of ~0.66 at 400–773 K in Bi1.98Pb0.02Si2Te6. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) Submitted/Accepted version This work was supported in part the Department of Energy, Office of Science Basic Energy Sciences under grant DESC0014520, DOE Office of Science (materials synthesis, TE characterization, TEM, DFT) and in part by the National Natural Science Foundation of China (Grant Nos. 52002137, 92163211, 51802070, and 51632006). This work made use of the EPIC facilities of Northwestern’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. User Facilities are supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-06CH11357 and DE-AC02- 05CH11231. Access to facilities of high-performance computational resources at the Northwestern University is acknowledged. The authors also acknowledge Singapore MOE AcRF Tier 2 under Grant Nos. 2018-T2-1-010, Singapore A*STAR Pharos Program SERC 1527200022, Singapore A*STAR project A19D9a0096, the Fundamental Research Funds for the Central Universities under Grant No. 2021XXJS008 and 2018KFYXKJC002. 2022-06-03T01:17:07Z 2022-06-03T01:17:07Z 2022 Journal Article Luo, Y., Ma, Z., Hao, S., Cai, S., Luo, Z., Wolverton, C., Dravid, V. P., Yang, J., Yan, Q. & Kanatzidis, M. G. (2022). Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor. Journal of the American Chemical Society, 144(3), 1445-1454. https://dx.doi.org/10.1021/jacs.1c12507 0002-7863 https://hdl.handle.net/10356/159223 10.1021/jacs.1c12507 3 144 1445 1454 en MOE 2018-T2-1-010 SERC 1527200022 A19D9a0096 Journal of the American Chemical Society This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/jacs.1c12507 application/pdf
spellingShingle Science::Chemistry::Inorganic chemistry
Engineering::Materials
Thermal Conductivity
Bi₂Si₂Te₆
Luo, Yubo
Ma, Zheng
Hao, Shiqiang
Cai, Songting
Luo, Zhong-Zhen
Wolverton, Christopher
Dravid, Vinayak P.
Yang, Junyou
Yan, Qingyu
Kanatzidis, Mercouri G.
Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor
title Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor
title_full Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor
title_fullStr Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor
title_full_unstemmed Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor
title_short Thermoelectric performance of the 2D Bi₂Si₂Te₆ semiconductor
title_sort thermoelectric performance of the 2d bi₂si₂te₆ semiconductor
topic Science::Chemistry::Inorganic chemistry
Engineering::Materials
Thermal Conductivity
Bi₂Si₂Te₆
url https://hdl.handle.net/10356/159223
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