1. Realizing high thermoelectric performance of polycrystalline SnS through optimizing carrier concentration and modifying band structure.
- Author
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Wang, Ziyao, Wang, Dongyang, Qiu, Yuting, He, Jiaqing, and Zhao, Li-Dong
- Subjects
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CARRIER density , *THERMOELECTRIC materials , *THERMOELECTRIC power , *ELECTRONIC band structure , *SEEBECK coefficient , *VALENCE bands , *THERMAL conductivity - Abstract
Tin sulfide (SnS), a typical IV–VI compound with low-cost, abundant-earth and eco-friendly elements, has aroused widespread attentions in the thermoelectric community due to its similar electron and phonon structures with SnSe. However, undoped SnS possesses the features of low carrier concentration and inferior band structures, which produces indecent thermoelectric performance. In this work, we successfully resolved these shortcomings of SnS through stepwise Na doping and Se alloying. Firstly, the carrier concentration of SnS was increased and optimized through Na doping, which leads to an enhancement both in electrical conductivity and Seebeck coefficients through activating multiple valance bands. Secondly, the electronic band structure of SnS was modified through Se alloying, both narrowing band gap and flatting valence band shape contribute excellent electrical transport properties, resulting in maximum power factor ∼6.0 μWcm−1K−2. After synergistically optimizing interdependent thermoelectric parameters through Na doping and Se alloying, a record high ZT of 0.70 at 873 K was obtained in polycrystalline SnS. Our work indicates that SnS is one of very promising earth-abundant thermoelectric materials for power generation in mediate-temperature range. • Power factor of p -type SnS was improved from 2.5 μWcm−1K−2 to 4.8 μWcm−1K−2 at 923 K through Na doping. • Power factor of p -type SnS was improved from 4.8 μWcm−1K−2 to 6.0 μWcm−1K−2 at 873 K through Se alloying. • ZT max of p -type SnS is distinctly enhanced from 0.25 to 0.70 at 873 K after Na doping and Se alloying. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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