Abstract
SnSe,possessing strong lattice anharmonicity and structural anisotropy,has attracted massive attention in thermoelectric conversion.Herein,we demonstrate that simultaneously optimized electrical and ther-mal transport properties are achieved in SnS2-alloyed SnSe polycrystalline materials,which were fabri-cated 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 ex-ample,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.
基金项目
国家自然科学基金(51802034)
国家自然科学基金(52071041)
国家自然科学基金(11904039)
国家自然科学基金(11874356)
重庆市自然科学基金(cstc2021jcyj-msxmX0407)
NETL
NSTL
万方数据