Achieving zT > 2 in p-Type AgSbTe2−xSex alloys via exploring the extra light valence band and introducing dense stacking faults
Article
Article Title | Achieving zT > 2 in p-Type AgSbTe2−xSex alloys via exploring the extra light valence band and introducing dense stacking faults |
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ERA Journal ID | 200105 |
Article Category | Article |
Authors | Hong, Min (Author), Chen, Zhi-Gang (Author), Yang, Lei (Author), Liao, Zhi-Ming (Author), Zou, Yi-Chao (Author), Chen, Yan-Hui (Author), Matsumura, Syo (Author) and Zou, Jin (Author) |
Journal Title | Advanced Energy Materials |
Journal Citation | 8 (9), pp. 1-7 |
Article Number | 1702333 |
Number of Pages | 7 |
Year | 2018 |
Publisher | John Wiley & Sons |
Place of Publication | Germany |
ISSN | 1614-6832 |
1614-6840 | |
Digital Object Identifier (DOI) | https://doi.org/10.1002/aenm.201702333 |
Web Address (URL) | https://onlinelibrary.wiley.com/doi/full/10.1002/aenm.201702333 |
Abstract | Through simultaneously enhancing the power factor by engineering the extra light band and enhancing phonon scatterings by introducing a high density of stacking faults, a record figure-of-merit over 2.0 is achieved in p-type AgSbTe2−xSex alloys. Density functional theory calculations confirm the presence of the light valence band with large degeneracy in AgSbTe2, and that alloying with Se decreases the energy offset between the light valence band and the valence band maximum. Therefore, a significantly enhanced power factor is realized in p-type AgSbTe2−xSex alloys. In addition, transmission electron microscopy studies indicate the appearance of stacking faults and grain boundaries, which together with grain boundaries and point defects significantly strengthen phonon scatterings, leading to an ultralow thermal conductivity. The synergetic strategy of simultaneously enhancing power factor and strengthening phonon scattering developed in this study opens up a robust pathway to tailor hermoelectric performance. |
Keywords | AgSbTe2− xSex alloys; engineering light valence band; stacking fault phonon scattering; thermoelectric |
ANZSRC Field of Research 2020 | 340210. Solid state chemistry |
401807. Nanomaterials | |
510403. Condensed matter modelling and density functional theory | |
401605. Functional materials | |
Byline Affiliations | University of Queensland |
Centre for Future Materials | |
Beijing University of Technology, China | |
Kyushu University, Japan | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q5050/achieving-zt-2-in-p-type-agsbte2-xsex-alloys-via-exploring-the-extra-light-valence-band-and-introducing-dense-stacking-faults
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