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dc.contributor.authorWei, Pai-Chun
dc.contributor.authorCai, Cheng-Xun
dc.contributor.authorHsing, Cheng-Rong
dc.contributor.authorWei, Ching-Ming
dc.contributor.authorYu, Shih-Hsun
dc.contributor.authorWu, Hsin-Jay
dc.contributor.authorChen, Cheng-Lung
dc.contributor.authorWei, Da-Hua
dc.contributor.authorNguyen, Duc-Long
dc.contributor.authorChou, Mitch M. C.
dc.contributor.authorChen, Yang-Yuan
dc.date.accessioned2019-08-08T11:18:43Z
dc.date.available2019-08-08T11:18:43Z
dc.date.issued2019-06-13
dc.identifier.citationWei, P.-C., Cai, C.-X., Hsing, C.-R., Wei, C.-M., Yu, S.-H., Wu, H.-J., … Chen, Y.-Y. (2019). Enhancing thermoelectric performance by Fermi level tuning and thermal conductivity degradation in (Ge1−xBix)Te crystals. Scientific Reports, 9(1). doi:10.1038/s41598-019-45071-9
dc.identifier.doi10.1038/s41598-019-45071-9
dc.identifier.urihttp://hdl.handle.net/10754/656431
dc.description.abstractIn this work, a high thermoelectric figure of merit, zT of 1.9 at 740 K is achieved in Ge1−xBixTe crystals through the concurrent of Seebeck coefficient enhancement and thermal conductivity reduction with Bi dopants. The substitution of Bi for Ge not only compensates the superfluous hole carriers in pristine GeTe but also shifts the Fermi level (EF) to an eligible region. Experimentally, with moderate 6–10% Bi dopants, the carrier concentration is drastically decreased from 8.7 × 1020 cm−3 to 3–5 × 1020 cm−3 and the Seebeck coefficient is boosted three times to 75 μVK−1. In the meantime, based on the density functional theory (DFT) calculation, the Fermi level EF starts to intersect with the pudding mold band at L point, where the band effective mass is enhanced. The enhanced Seebeck coefficient effectively compensates the decrease of electrical conductivity and thus successfully maintain the power factor as large as or even superior than that of the pristine GeTe. In addition, the Bi doping significantly reduces both thermal conductivities of carriers and lattices to an extremely low limit of 1.57 W m−1K−1 at 740 K with 10% Bi dopants, which is an about 63% reduction as compared with that of pristine GeTe. The elevated figure of merit observed in Ge1−xBixTe specimens is therefore realized by synergistically optimizing the power factor and downgrading the thermal conductivity of alloying effect and lattice anharmonicity caused by Bi doping.
dc.description.sponsorshipThis work is fnancially supported by Ministry of Science and Technology (MOST), Taiwan, Grant No. MOST 106-2112-M-001 -019 -MY3
dc.publisherSpringer Nature
dc.relation.urlhttp://www.nature.com/articles/s41598-019-45071-9
dc.rightsThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Te images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/.
dc.titleEnhancing thermoelectric performance by Fermi level tuning and thermal conductivity degradation in (Ge1−xBix)Te crystals
dc.typeArticle
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
dc.identifier.journalScientific Reports
dc.eprint.versionPublisher's Version/PDF
dc.contributor.institutionInstitute of Physics, Academia Sinica, Taipei, Taiwan
dc.contributor.institutionGraduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, Taiwan
dc.contributor.institutionInstitute of Atomic and Molecular Science, Academia Sinica, Taipei, Taiwan
dc.contributor.institutionDepartment of Materials and Optoelectronic Science, National Sun Yat-sen University, Kaohsiung, Taiwan
dc.contributor.institutionDepartment of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
kaust.personWei, Pai-Chun
refterms.dateFOA2019-08-08T11:19:39Z
dc.date.published-online2019-06-13
dc.date.published-print2019-12


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This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Te images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Except where otherwise noted, this item's license is described as This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Te images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.