Attaining enhanced thermoelectric performance in p-type (SnSe)1–x(SnS2)x produced via sintering their solution-synthesized micro/nanostructures. (1st September 2022)

• Record Type: Journal Article
• Authors: Liu, Xiaofang; Wang, Hengyang; Zhang, Bin; Zheng, Sikang; Chen, Yao; Zhang, Hong; Chen, Xianhua; Wang, Guoyu; Zhou, Xiaoyuan; Han, Guang
• Is Part Of: Journal of materials science & technology. Volume 120(2022)
• Page Start: 205
• Page End: 213
• Publication Date: 2022-09-01
• Subjects: Thermoelectric -- SnSe -- SnS2 -- Solvothermal synthesis -- Lattice thermal conductivity; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2021.11.072
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: (SnSe)1– x (SnS2 ) x materials were synthesized by sintering SnSe microplates and SnS2 nanoplates. By tuning the alloying amount of SnS2, the carrier concentration and power factor of SnSe are optimized. κ lat is reduced resulting from the enhanced phonon scattering by various crystal defects. SnS2 alloying synergistically optimizes the electrical and thermal properties of polycrystalline SnSe . Abstract: SnSe, possessing strong lattice anharmonicity and structural anisotropy, has attracted massive attention in thermoelectric conversion. Herein, we demonstrate that simultaneously optimized electrical and thermal transport properties are achieved in SnS2 -alloyed SnSe polycrystalline materials, which were fabricated via sintering the mixture of solution-synthesized SnSe microplates and SnS2 nanoplates. Resulting from the increased carrier concentration, p-type (SnSe)1– x (SnS2 ) x ( x = 0.5%, 1%) samples obtain much-improved power factor between 300 K and 373 K, e.g. 0.72 mW m –1 K –2 at 300 K for (SnSe)0.99 (SnS2 )0.01, which is enhanced by 53% compared to that of SnSe. Additionally, the existing point defects and planar defects effectively strengthen phonon scattering, thus reducing the lattice thermal conductivity, for example, 0.47 W m –1 K –1 at 773 K for the x = 0.02 sample. Eventually, a maximum zT of 0.80 at 823 K and an average zT of 0.52 over 300 – 823 K are obtained in the (SnSe)0.99 (SnS2 )0.01 sample, which are increased by 33% and 45% compared to those of SnSe, respectively. This study demonstrates a secondary phase alloying strategy to synergistically optimize the electrical and thermal properties of polycrystalline SnSe. Abstract : Image, graphical abstract