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Realizing high thermoelectricity in polycrystalline tin sulfide via manipulating fermi surface anisotropy and phonon dispersion
Wu, H.1,2; Peng, K.1; Zhang, B.3; Gong, X. N.3; Feng, Z. Z.4; Zhang, X. M.4; Xi, M.1; Yan, X. M.1; Zhang, Y. S.4; Wang, G. Y.2
2020-08-01
摘要Tin sulfide (SnS) with an analogous structure to SnSe has attracted increasing attentions owing to its low cost, earth abundance, and environmental compatibility. In this work, the thermoelectric properties of polycrystalline SnS1-xSex (0 <= x <= 0.5) are systematically investigated. With the assistance of the theoretical calculations and experimental results, the intrinsic characteristic of the markedly diminished lattice thermal conductivity with increasing Se alloying content is due to the decreased phonon vibration frequency associated with the reduced phonon group velocity and the strengthened phonon scattering. In addition, compared with SnS, the more localized Sn_5s(2) lone pair electrons in SnS0.5Se0.5 are propitious to strengthen the anisotropy of Fermi surface and lattice anharmonicity, leading to high quality factor (B). Finally, a highest zT value (similar to 1.1) at 820 K is obtained for Na0.02Sn0.98S0.5Se0.5 by optimizing the carrier concentration through Na doping. These results contribute to a comprehensive understanding of the modification of phonon dispersion and band structure of SnS-SnSe solid solutions and indicate their high thermoelectric performance in SnS-based materials. (C) 2020 Elsevier Ltd. All rights reserved.
关键词Thermoelectric SnS Fermi surface anisotropy Phonon dispersion Lattice dynamics
DOI10.1016/j.mtphys.2020.100221
发表期刊MATERIALS TODAY PHYSICS
ISSN2542-5293
卷号14页码:10
通讯作者Wang, G. Y.(guoyuw@cigit.ac.cn) ; Lu, X.(luxu@cqu.edu.cn) ; Zhou, X. Y.(xiaoyuan2013@cqu.edu.cn)
收录类别SCI
WOS记录号WOS:000572900300002
语种英语