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

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 SnS_(2) -alloyed SnSe polycrystalline materials,which were fabricated via sintering the mixture of solution-synthesized SnSe microplates and SnS_(2) nanoplates.Resulting from the increased carrier concentration,p-type(SnSe)_(1–x)(SnS_(2))_(x)(x=0.5%,1%)samples obtain muchimproved power factor between 300 K and 373 K,e.g.0.72 mW m^(–1)K^(–2)at 300 K for(SnSe)0.99(SnS_(2) )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(SnS_(2))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.