Chemical Pressure‐Induced Unconventional Band Convergence Leads to High Thermoelectric Performance in SnTe
Abstract Band convergence is considered a net benefit to thermoelectric performance as it decouples the density of states effective mass (md∗) and carrier mobility (µ) by increasing valley degeneracy. Unlike conventional methods that typically prioritize md∗ at the expense of µ, this study theoretic...
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Wiley
2025-01-01
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| Series: | Advanced Science |
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| Online Access: | https://doi.org/10.1002/advs.202409735 |
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| author | Hongwei Ming Zhong‐Zhen Luo Zhigang Zou |
| author_facet | Hongwei Ming Zhong‐Zhen Luo Zhigang Zou |
| author_sort | Hongwei Ming |
| collection | DOAJ |
| description | Abstract Band convergence is considered a net benefit to thermoelectric performance as it decouples the density of states effective mass (md∗) and carrier mobility (µ) by increasing valley degeneracy. Unlike conventional methods that typically prioritize md∗ at the expense of µ, this study theoretically demonstrates an unconventional band convergence strategy to enhance both md∗ and µ in SnTe under pressure. Density functional theory calculations reveal that increasing pressure from 0 to 5 GPa moves the Σ‐band of SnTe upward, reducing the energy offset between L‐ and Σ‐band from 0.35 to 0.2 eV while preserving the light band feature of the L‐band. Consequently, a high power factor (PF) of 119.2 µW cm−1 K−2 at 300 K is achieved for p‐type SnTe under 5 GPa. Chemical pressure also induces conduction band convergence, significantly enhancing the PF of n‐type SnTe. Additionally, the interplay between pressure‐induced phonon modes leads to a moderate increase in lattice thermal conductivity of SnTe below 3 GPa, which combined with the significantly enhanced PF, contributes to a large enhancement in ZT. Consequently, predicted ZT values of 2.12 at 650 K and 2.55 at 850 K are obtained for p‐ and n‐type SnTe, respectively, showcasing substantial performance enhancements. |
| format | Article |
| id | doaj-art-5840d1fadda743f4a6f7d2704f60efba |
| institution | Kabale University |
| issn | 2198-3844 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Wiley |
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| series | Advanced Science |
| spelling | doaj-art-5840d1fadda743f4a6f7d2704f60efba2025-01-09T11:44:46ZengWileyAdvanced Science2198-38442025-01-01121n/an/a10.1002/advs.202409735Chemical Pressure‐Induced Unconventional Band Convergence Leads to High Thermoelectric Performance in SnTeHongwei Ming0Zhong‐Zhen Luo1Zhigang Zou2Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou Fujian 350108 P. R. ChinaFujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou Fujian 350108 P. R. ChinaFujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou Fujian 350108 P. R. ChinaAbstract Band convergence is considered a net benefit to thermoelectric performance as it decouples the density of states effective mass (md∗) and carrier mobility (µ) by increasing valley degeneracy. Unlike conventional methods that typically prioritize md∗ at the expense of µ, this study theoretically demonstrates an unconventional band convergence strategy to enhance both md∗ and µ in SnTe under pressure. Density functional theory calculations reveal that increasing pressure from 0 to 5 GPa moves the Σ‐band of SnTe upward, reducing the energy offset between L‐ and Σ‐band from 0.35 to 0.2 eV while preserving the light band feature of the L‐band. Consequently, a high power factor (PF) of 119.2 µW cm−1 K−2 at 300 K is achieved for p‐type SnTe under 5 GPa. Chemical pressure also induces conduction band convergence, significantly enhancing the PF of n‐type SnTe. Additionally, the interplay between pressure‐induced phonon modes leads to a moderate increase in lattice thermal conductivity of SnTe below 3 GPa, which combined with the significantly enhanced PF, contributes to a large enhancement in ZT. Consequently, predicted ZT values of 2.12 at 650 K and 2.55 at 850 K are obtained for p‐ and n‐type SnTe, respectively, showcasing substantial performance enhancements.https://doi.org/10.1002/advs.202409735band convergencechemical pressurefermi velocityphonon scatteringSnTe |
| spellingShingle | Hongwei Ming Zhong‐Zhen Luo Zhigang Zou Chemical Pressure‐Induced Unconventional Band Convergence Leads to High Thermoelectric Performance in SnTe Advanced Science band convergence chemical pressure fermi velocity phonon scattering SnTe |
| title | Chemical Pressure‐Induced Unconventional Band Convergence Leads to High Thermoelectric Performance in SnTe |
| title_full | Chemical Pressure‐Induced Unconventional Band Convergence Leads to High Thermoelectric Performance in SnTe |
| title_fullStr | Chemical Pressure‐Induced Unconventional Band Convergence Leads to High Thermoelectric Performance in SnTe |
| title_full_unstemmed | Chemical Pressure‐Induced Unconventional Band Convergence Leads to High Thermoelectric Performance in SnTe |
| title_short | Chemical Pressure‐Induced Unconventional Band Convergence Leads to High Thermoelectric Performance in SnTe |
| title_sort | chemical pressure induced unconventional band convergence leads to high thermoelectric performance in snte |
| topic | band convergence chemical pressure fermi velocity phonon scattering SnTe |
| url | https://doi.org/10.1002/advs.202409735 |
| work_keys_str_mv | AT hongweiming chemicalpressureinducedunconventionalbandconvergenceleadstohighthermoelectricperformanceinsnte AT zhongzhenluo chemicalpressureinducedunconventionalbandconvergenceleadstohighthermoelectricperformanceinsnte AT zhigangzou chemicalpressureinducedunconventionalbandconvergenceleadstohighthermoelectricperformanceinsnte |