title: Synergistic Strategy to Enhance the Thermoelectric Properties of CoSbS1-xSexCompounds via Solid Solution.
abstract: High thermal conductivity of CoSbS-based limited its own prospect application in thermoelectric energy conversion. Solid solution is an effective approach to optimize the performance of thermoelectric materials with high lattice thermal conductivity because of the enhanced phonons scattering from disorder atoms. In this paper, we have synthesized and measured the thermoelectric properties of solid solution CoSbS1-xSex(x = 0, 0.05, 0.10, 0.15, 0.20, 0.30) series samples. The collaborative optimization (enhancing the power factors and reducing the thermal conductivities) to add zT values were realized via substitution of S atoms with the isoelectronic Se atoms in the matrix. Meanwhile, the lowest room temperature lattice thermal conductivity in CoSbS-based materials is obtained (4.72 W m-1K-1) at present. Benefiting from the results of synergistic strategy, a zT of 0.35 was achieved at 923 K for sample CoSbS0.85Se0.15, a 59% improvement as compared with that of the pristine CoSbS. Band calculation demonstrated that CoSbS0.85Se0.15present a similar band dispersion with CoSbS. The mechanism of point defect scattering for reducing the lattice thermal conductivity at room temperature, was also analyzed by the Callaway model. The contributions to decrease the room temperature lattice thermal conductivity from the mass and the strain fluctuation in the crystal are comparable. These results can also be extended to other high-efficiency thermoelectric materials with stiff bond and smaller Gruneisen parameters.
authors.affiliation: College of Physics, Chongqing University , Chongqing 401331, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yao
authors.affiliation: Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences , Chongqing 400714, People's Republic of China.
authors.forename: Dingfeng
authors.initials: D
authors.lastname: Yang
authors.affiliation: College of Physics, Chongqing University , Chongqing 401331, People's Republic of China.|Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences , Chongqing 400714, People's Republic of China.
authors.forename: Yanci
authors.initials: Y
authors.lastname: Yan
authors.affiliation: College of Physics, Chongqing University , Chongqing 401331, People's Republic of China.|Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences , Chongqing 400714, People's Republic of China.
authors.forename: Kunling
authors.initials: K
authors.lastname: Peng
authors.affiliation: College of Physics, Chongqing University , Chongqing 401331, People's Republic of China.
authors.forename: Heng
authors.initials: H
authors.lastname: Zhan
authors.affiliation: College of Physics, Chongqing University , Chongqing 401331, People's Republic of China.
authors.forename: Anping
authors.initials: A
authors.lastname: Liu
authors.affiliation: College of Physics, Chongqing University , Chongqing 401331, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: Lu
authors.affiliation: Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences , Chongqing 400714, People's Republic of China.
authors.forename: Guoyu
authors.initials: G
authors.lastname: Wang
authors.affiliation: College of Physics, Chongqing University , Chongqing 401331, People's Republic of China.
authors.forename: Xiaoyuan
authors.identifier: http://orcid.org/0000-0002-0930-1278
authors.initials: X
authors.lastname: Zhou
keywords: CoSbS; point defect; solid solution; thermal conductivity; zT