Enhancing thermoelectric performance of SrFBiS_(2-x)Se_(x) via band engineering and structural texturing  

作　　者：Hai Huang Chen Lin Shijing Li Kai Guo Jianxin Zhang Wanyu Lyu Jiye Zhang Juanjuan Xing Ying Jiang Jiong Yang Jun Luo 

机构地区：[1]School of Materials Science and Engineering,Shanghai University,99 Shangda Road,Shanghai,200444,China [2]Materials Genome Institute,Shanghai University,99 Shangda Road,Shanghai,200444,China [3]School of Physics and Materials Science,Guangzhou University,Guangzhou,510006,China [4]Centre for Future Materials,University of Southern Queensland,Springfield Central,QLD,4300,Australia

出　　处：《Journal of Materiomics》2022年第2期302-310,共9页无机材料学学报（英文）

基　　金：This work was financially supported by the National Key Research and Development Program of China(2018YFA0702100);the National Natural Science Foundation of China(21771123,52072234);J.Zhang is grateful for the support by the Open Project of Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices(KJS2023).

摘　　要：SrFBiS_(2) is a quaternary n-type semiconductor with rock-salt-type BiS_(2) and fluorite-type SrF layers alternately stacked along the c axis.The tunability of the crystal and electronic structures as well as the intrinsically low thermal conductivity make this compound a promising parent material for thermo-electric applications.In the current work,we show that alloying of Se and S in SrFBi_(S) 2 reduces the optical band gap with the second conduction band serving as an electron-transport medium,simultaneously increasing the electron concentration and effective mass.In addition,the raw material Bi_(2)Se_(3) is shown to act as liquid adjuvant during the annealing process,favoring preferred-orientation grain growth and forming strengthen microstructural texturing in bulk samples after hot-pressed sintering.Highly ordered lamellar grains are stacked perpendicular to the pressure direction,leading to enhanced mobility along this direction.The synthetic effect results in a maximum power factor of 5.58 μm W cm^(-1) K^(-2) at 523 K for SrFBiSSe and a peak zT=0.34 at 773 K,enhancements of 180%compared with those of pristine SrFBiS_(2).

关 键 词：SrFBiS_(2) Layered compound Energy band engineering Carrier mobility TEXTURING 

分 类 号：TB34[一般工业技术—材料科学与工程]