High thermoelectric figure of merit ZT>1 in SnS polycrystals  

作　　者：Asfandiyar Bowen Cai Li-Dong Zhao Jing-Feng Li 

机构地区：[1]State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing,100084,China [2]School of Materials Science and Engineering,Beihang University,Beijing,100191,China

出　　处：《Journal of Materiomics》2020年第1期77-85,共9页无机材料学学报（英文）

基　　金：supported by the Basic Science Center Project of Natural Science Foundation of China(51788104);the National Key R&D Program of China(2018YFB0703603).

摘　　要：Eco-friendly tin sulfide(SnS)has attracted increasing attention in the thermoelectric community because of its elemental abundance and analogous crystal structure to SnSe as a new thermoelectric material.However,so far no high dimensionless thermoelectric figure of merit ZT>1 was reported in SnS polycrystals.This work found an effective strategy for enhancing the thermoelectric performance of ptype polycrystalline SnS by Ag doping and vacancy engineering,leading to three orders of magnitude increase in carrier concentration and optimized effective mass and carrier mobility.As a result of the enhanced electrical conductivity,three times higher power factor ~3.85 μW/cm K^(2) at 877 K is realized in Sn_(0.995)Ag_(0.005)S sample.Interestingly,nanostructuring with Ag nano-precipitates were formed in the Agdoped SnS sample.Moreover,with introducing Sn vacancies in the crystal structure of Sn_(0.995-vac)Ag_(0.005)S,the power factor further enhanced to~4.25 μW/cm K^(2).In addition to the low-frequency phonons scattering by Ag nano-precipitates,dislocations strengthens the scattering of mid-frequency phonon,leading to an ultralow lattice thermal conductivity <0.5 W/m K above 800 K and a record high ZT up to 1.1 at 877 K in Sn_(0.99)Ag_(0.005)S polycrystals.

关 键 词：Thermoelectric tin sulfide Spark plasma sintering NANOPRECIPITATION DISLOCATION 

分 类 号：TB34[一般工业技术—材料科学与工程]