Two-step phase manipulation by tailoring chemical bonds results in high-performance GeSe thermoelectrics
Article
Yao, Wenqing, Zha, Yihua, Lyu, Tu, Huang, Weibo, Huang, Nuoxian, Li, Xiang, Zhang, Chaohua, Liu, Fusheng, Wuttig, Matthias, Yu, Yuan, Hong, Min and Hu, Lipeng. 2023. "Two-step phase manipulation by tailoring chemical bonds results in high-performance GeSe thermoelectrics." The Innovation. 4 (6).
Article Title | Two-step phase manipulation by tailoring chemical bonds results in high-performance GeSe thermoelectrics |
---|---|
ERA Journal ID | 214291 |
Article Category | Article |
Authors | Yao, Wenqing, Zha, Yihua, Lyu, Tu, Huang, Weibo, Huang, Nuoxian, Li, Xiang, Zhang, Chaohua, Liu, Fusheng, Wuttig, Matthias, Yu, Yuan, Hong, Min and Hu, Lipeng |
Journal Title | The Innovation |
Journal Citation | 4 (6) |
Article Number | 100522 |
Number of Pages | 24 |
Year | 2023 |
Publisher | Cell Press |
ISSN | 2666-6758 |
Abstract | In thermoelectrics, phase engineering serves a crucial function in determining the power factor by affecting the band degeneracy. However, for low-symmetry compounds, the mainstream one-step phase manipulation strategy, depending solely on the valley or orbital degeneracy, is inadequate to attain a high density-of-states effective mass and exceptional zT. Here, we employ a distinctive two-step phase manipulation strategy through stepwise tailoring chemical bonds in GeSe. Initially, we amplify the valley degeneracy via CdTe alloying, which elevates the crystal symmetry from a covalently bonded orthorhombic to a metavalently bonded rhombohedral phase by significantly suppressing the Peierls distortion. Subsequently, we incorporate Pb to trigger the convergence of multivalence bands and further enhance the density-of-states effective mass by moderately restraining the Peierls distortion. Additionally, the atypical metavalent bonding in rhombohedral GeSe enables a high Ge vacancy concentration and a small band effective mass, leading to increased carrier concentration and mobility. This weak chemical bond along with strong lattice anharmonicity also reduces lattice thermal conductivity. Consequently, this unique property ensemble contributes to an outstanding zT of 0.9 at 773 K for Ge0.80Pb0.20Se(CdTe)0.25. This work underscores the pivotal role of the two-step phase manipulation by stepwise tailoring of chemical bonds in improving the thermoelectric performance of p-bonded chalcogenides. © 2023 The Author(s) |
ANZSRC Field of Research 2020 | 401605. Functional materials |
Byline Affiliations | Shenzhen University, China |
RWTH Aachen University, Germany | |
Forschungszentrum Julich, Germany |
Permalink -
https://research.usq.edu.au/item/z2732/two-step-phase-manipulation-by-tailoring-chemical-bonds-results-in-high-performance-gese-thermoelectrics
48
total views0
total downloads1
views this month0
downloads this month