Electron mean-free-path filtering in Dirac material for improved thermoelectric performance
Recent advancements in thermoelectric materials have largely benefited from various approaches, including band engineering and defect optimization, among which the nanostructuring technique presents a promising way to improve the thermoelectric figure of merit (zT) by means of reducing the character...
| Main Authors: | , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Published: |
National Academy of Sciences (U.S.)
2018
|
| Online Access: | http://hdl.handle.net/1721.1/118460 https://orcid.org/0000-0002-1157-8540 https://orcid.org/0000-0002-9872-5688 https://orcid.org/0000-0002-7055-6368 https://orcid.org/0000-0002-2612-7750 https://orcid.org/0000-0002-1090-4068 https://orcid.org/0000-0002-8803-1017 |
| _version_ | 1811083141196021760 |
|---|---|
| author | Liu, Te Huan Zhou, Jiawei Li, Mingda Ding, Zhiwei Song, Qichen Fu, Liang Chen, Gang |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Liu, Te Huan Zhou, Jiawei Li, Mingda Ding, Zhiwei Song, Qichen Fu, Liang Chen, Gang |
| author_sort | Liu, Te Huan |
| collection | MIT |
| description | Recent advancements in thermoelectric materials have largely benefited from various approaches, including band engineering and defect optimization, among which the nanostructuring technique presents a promising way to improve the thermoelectric figure of merit (zT) by means of reducing the characteristic length of the nanostructure, which relies on the belief that phonons’ mean free paths (MFPs) are typically much longer than electrons’. Pushing the nanostructure sizes down to the length scale dictated by electron MFPs, however, has hitherto been overlooked as it inevitably sacrifices electrical conduction. Here we report through ab initio simulations that Dirac material can overcome this limitation. The monotonically decreasing trend of the electron MFP allows filtering of long-MFP electrons that are detrimental to the Seebeck coefficient, leading to a dramatically enhanced power factor. Using SnTe as a material platform, we uncover this MFP filtering effect as arising from its unique nonparabolic Dirac band dispersion. Room-temperature zT can be enhanced by nearly a factor of 3 if one designs nanostructures with grain sizes of ∼10 nm. Our work broadens the scope of the nanostructuring approach for improving the thermoelectric performance, especially for materials with topologically nontrivial electronic dynamics. Keywords: Dirac material; electrom mean-free-path filtering; thermoelectrics; nanostructuring approach; electron-phonon interactions |
| first_indexed | 2024-09-23T12:24:30Z |
| format | Article |
| id | mit-1721.1/118460 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T12:24:30Z |
| publishDate | 2018 |
| publisher | National Academy of Sciences (U.S.) |
| record_format | dspace |
| spelling | mit-1721.1/1184602022-10-01T09:07:45Z Electron mean-free-path filtering in Dirac material for improved thermoelectric performance Liu, Te Huan Zhou, Jiawei Li, Mingda Ding, Zhiwei Song, Qichen Fu, Liang Chen, Gang Massachusetts Institute of Technology. Department of Mechanical Engineering Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Laboratory for Nuclear Science Liu, Te Huan Zhou, Jiawei Li, Mingda Ding, Zhiwei Song, Qichen Fu, Liang Chen, Gang Recent advancements in thermoelectric materials have largely benefited from various approaches, including band engineering and defect optimization, among which the nanostructuring technique presents a promising way to improve the thermoelectric figure of merit (zT) by means of reducing the characteristic length of the nanostructure, which relies on the belief that phonons’ mean free paths (MFPs) are typically much longer than electrons’. Pushing the nanostructure sizes down to the length scale dictated by electron MFPs, however, has hitherto been overlooked as it inevitably sacrifices electrical conduction. Here we report through ab initio simulations that Dirac material can overcome this limitation. The monotonically decreasing trend of the electron MFP allows filtering of long-MFP electrons that are detrimental to the Seebeck coefficient, leading to a dramatically enhanced power factor. Using SnTe as a material platform, we uncover this MFP filtering effect as arising from its unique nonparabolic Dirac band dispersion. Room-temperature zT can be enhanced by nearly a factor of 3 if one designs nanostructures with grain sizes of ∼10 nm. Our work broadens the scope of the nanostructuring approach for improving the thermoelectric performance, especially for materials with topologically nontrivial electronic dynamics. Keywords: Dirac material; electrom mean-free-path filtering; thermoelectrics; nanostructuring approach; electron-phonon interactions 2018-10-12T16:39:56Z 2018-10-12T16:39:56Z 2018-01 2017-09 2018-09-26T12:01:13Z Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/118460 Liu, Te-Huan et al. “Electron Mean-Free-Path Filtering in Dirac Material for Improved Thermoelectric Performance.” Proceedings of the National Academy of Sciences 115, 5 (January 2018): 879–884 © 2018 National Academy of Sciences https://orcid.org/0000-0002-1157-8540 https://orcid.org/0000-0002-9872-5688 https://orcid.org/0000-0002-7055-6368 https://orcid.org/0000-0002-2612-7750 https://orcid.org/0000-0002-1090-4068 https://orcid.org/0000-0002-8803-1017 http://dx.doi.org/10.1073/PNAS.1715477115 Proceedings of the National Academy of Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences (U.S.) PNAS |
| spellingShingle | Liu, Te Huan Zhou, Jiawei Li, Mingda Ding, Zhiwei Song, Qichen Fu, Liang Chen, Gang Electron mean-free-path filtering in Dirac material for improved thermoelectric performance |
| title | Electron mean-free-path filtering in Dirac material for improved thermoelectric performance |
| title_full | Electron mean-free-path filtering in Dirac material for improved thermoelectric performance |
| title_fullStr | Electron mean-free-path filtering in Dirac material for improved thermoelectric performance |
| title_full_unstemmed | Electron mean-free-path filtering in Dirac material for improved thermoelectric performance |
| title_short | Electron mean-free-path filtering in Dirac material for improved thermoelectric performance |
| title_sort | electron mean free path filtering in dirac material for improved thermoelectric performance |
| url | http://hdl.handle.net/1721.1/118460 https://orcid.org/0000-0002-1157-8540 https://orcid.org/0000-0002-9872-5688 https://orcid.org/0000-0002-7055-6368 https://orcid.org/0000-0002-2612-7750 https://orcid.org/0000-0002-1090-4068 https://orcid.org/0000-0002-8803-1017 |
| work_keys_str_mv | AT liutehuan electronmeanfreepathfilteringindiracmaterialforimprovedthermoelectricperformance AT zhoujiawei electronmeanfreepathfilteringindiracmaterialforimprovedthermoelectricperformance AT limingda electronmeanfreepathfilteringindiracmaterialforimprovedthermoelectricperformance AT dingzhiwei electronmeanfreepathfilteringindiracmaterialforimprovedthermoelectricperformance AT songqichen electronmeanfreepathfilteringindiracmaterialforimprovedthermoelectricperformance AT fuliang electronmeanfreepathfilteringindiracmaterialforimprovedthermoelectricperformance AT chengang electronmeanfreepathfilteringindiracmaterialforimprovedthermoelectricperformance |