Optimization of the average figure-of-merit zT in medium-entropy GeTe-based materials via entropy engineering  

作　　者：Xusheng Liu Keli Wang Peng Li Qiqi Tang Zhenlong Huang Yuan Lin Wu Wang Binbin Jiang Jiaqing He 

机构地区：[1]School of Materials and Energy,University of Electronic Science and Technology of China,Chengdu,610054,China [2]Shenzhen Institute for Advanced Study,University of Electronic Science and Technology of China,Shenzhen,518110,China [3]Shenzhen Key Laboratory of Thermoelectric Materials,Department of Physics,Southern University of Science and Technology,Shenzhen,518055,China [4]Institute of Atomic and Molecular Physics,Sichuan University,Chengdu,610065,China

出　　处：《Journal of Materiomics》2024年第4期956-963,共8页无机材料学学报（英文）

基　　金：This work is supported by the National Natural Science Foundation of China(Grant No.52222209,11934007,and 52302262);the Science and Technology Innovation Committee Foundation of Shenzhen(Grant No.JCYJ20220530165000001);the Young Elite Scientists Sponsorship Program by CAST(Grant No.2021QNRC001);the Outstanding Talents Training Fund in Shenzhen(202108);the Natural Science Foundation of Sichuan(Grant No.2023NSFSC0953).

摘　　要：Entropy engineering has emerged as an effective strategy for improving the figure-of-merit zT by decelerating the phonon transport while maintaining good electrical transport properties of thermoelectric materials.Herein,a high average zT of 1.54 and a maximum zT of 2.1 are achieved in the mid-entropy GeTe constructed by Ag,Sb,and Pb alloying.At room temperature,the mid-entropy GeTe tends to be a cubic structure.And the power factor is improved from 7.7μW·cm^(-1)·K^(-2) to 16.2μW·cm·cm^(-1)·K^(-2) due to the large increase in effective mass and the optimized carrier concentration.The increasing disorder created by heavy and off-centering Ag,Sb,and Pb atoms induces strong mass/strain fluctuations and phonon scattering to decelerate the phonon transport in GeTe.A low lattice thermal conductivity is obtained in the medium-entropy GeTe-based material.Moreover,a GeTe-based thermoelectric cooler is fabricated with the cooling temperature difference of 66.6 K with the hot end fixed at 363 K.This work reveals the effectiveness of entropy engineering in improving the average zT in GeTe and shows potential application of GeTe as a thermoelectric cooler.

关 键 词：Thermoelectric Germanium telluride Entropy engineering Thermoelectric cooler 

分 类 号：O48[理学—固体物理]