title: Realizing High Figure of Merit in Phase-Separated Polycrystalline Sn1-xPbxSe.
abstract: Solid-state thermoelectric technology, interconverting heat to electrical energy, offers a promising solution for relaxing global energy problems. A high dimensionless figure of merit ZT is desirable for high-efficiency thermoelectric power generation. To date, thermoelectric materials research has focused on increasing the material's ZT. Here we first fabricated phase-separated Sn1-xPbxSe materials by hydrothermal synthesis. We demonstrate that the simultaneous optimization of the power factor and significant reduction in thermal conductivity can be achieved in the phase-separated Sn1-xPbxSe material. The introduction of the PbSe phase contributes to improvement of the electrical conductivity and power factor of the SnSe phase. Meanwhile, nanoscale precipitates and mesoscale grains define all-scale hierarchical architectures to scattering phonons, leading to low lattice thermal conductivity. These two favorable factors lead to remarkably high thermoelectric performance with ZT ∼ 1.7 at 873 K in polycrystalline SnSe + 1% PbSe along the pressing direction, which is a record-high ZT for SnSe polycrystals. These findings highlight the prospects of realizing highly effective solid-state thermoelectric devices.
authors.affiliation: School of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Tang
authors.affiliation: School of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences , Hefei 230031, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
authors.forename: Guizhou
authors.initials: G
authors.lastname: Xu
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 10091, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Chang
authors.affiliation: National Laboratory of Solid State Microstructures, Department of Physics, Nanjing University , Nanjing 210093, China.
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Wang
authors.affiliation: National Laboratory of Solid State Microstructures, Department of Physics, Nanjing University , Nanjing 210093, China.
authors.forename: Youwei
authors.initials: Y
authors.lastname: Du
authors.affiliation: School of Materials Science and Engineering, Beihang University , Beijing 10091, China.
authors.forename: Li-Dong
authors.initials: LD
authors.lastname: Zhao