Enhanced thermoelectric performance in MnTe due to doping and insitu nanocompositing effects by Ag2S addition  

作　　者：Jinfeng Dong Jun Pei Kei Hayashi Wataru Saito Hezhang Li Bowen Cai Yuzuru Miyazaki 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]Department of Applied Physics,Graduate School of Engineering,Tohoku University,Sendai,980-8579,Japan

出　　处：《Journal of Materiomics》2021年第3期577-584,共8页无机材料学学报（英文）

基　　金：supported by the National Key R&D Program of China(No.2018YFB0703603)。

摘　　要：Extremely low lattice thermal conductivity is always the pursuit of thermoelectric materials research.In this work,we reported an exceptional effect of Ag2S addition in MnTe,an emerging promising midtemperature thermoelectric material,to enable the realization of minimum lattice thermal conductivity,namely-0.4 Wm^(-1) K^(-1).Such a low lattice thermal conductivity is guaranteed by the incorporation of in-situ formed Ag rich phase(Ag2Te)with ultralow lattice thermal conductivity and further scattering of phonons from the partial doping effects induced point defects and boundaries between various phases.Apart from the dramatically decreased lattice thermal conductivity,the partial doping of Ag and S simultaneously enhance the electrical conductivity,further contributing to enhanced thermoelectric performance.Meanwhile,an inverse sign of Seebeck and Hall coefficient was observed and rationalized by the influence of highly electron-conductive Ag_(2)Te phase.Thanks to the synergetic modulation of electrical and thermal transport properties by in-situ formed composite,a high ZT value of 1.1 was achieved in MnTe based thermoelectric materials,which also demonstrates the importance of compositing approaches to design state-of-the-art thermoelectric materials.

关 键 词：Manganese telluride THERMOELECTRIC Thermal conductivity Composite 

分 类 号：TB33[一般工业技术—材料科学与工程]