Defect engineering synergistically modulates power factor and thermal conductivity of CuGaTe2 for ultra-high thermoelectric performance

作     者：Zipei Zhang Wenhao Li Lu Yu Sitong Wei Shikai Wei Zhen Ji Weiyu Song Shuqi Zheng Zipei Zhang;Wenhao Li;Lu Yu;Sitong Wei;Shikai Wei;Zhen Ji;Weiyu Song;Shuqi Zheng

作者机构：State Key Laboratory of Heavy Oil ProcessingCollege of New Energy and MaterialsChina University of PetroleumBeijing 102249China College of ScienceChina University of PetroleumBeijing 102249China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2022年第128卷第33期

页      面：213-220页

核心收录：

学科分类：08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：financially supported by the National Natural Science Foundation of China(No.51871240) supported by the National Supercomputing Center in Shenzhen(Shenzhen Cloud Computing Center)。 

主　　题：Thermoelectric CuGaTe_(2) Carrier concentration Thermal conductivity 

摘      要：The ternary chalcopyrite CuGaTe_(2)has emerged as a promising p-type thermoelectric material with its advantages of low cost,good stability,and non-toxic elements.However,its thermoelectric performance is limited by the intrinsic low electrical conductivity and high lattice thermal conductivity.In this work,A deficiency of Cu in Cu_(1–x)Ga Te_(2)semiconductors can be used to optimize the electrical properties by improving the carrier concentration and to reduce thermal conductivity through multi-scale phonon scattering,which is predicted and guided by the First-principles density functional theory calculations.The carrier concentration is increased to 1020,which compensates for the low electrical performance caused by the intrinsic low nHof CuGaTe_(2).The average power factor of Cu_(0.96)Ga Te_(2)reaches 106.3%higher than that of the original CuGaTe_(2).In addition,the lattice thermal conductivity of the defective samples is greatly reduced at high temperatures,which is mainly due to the reduction of sound speed and phonon scattering.All the above factors contribute to the highest dimensionless figure of merit(ZT)value of 1.23 at 823 K in Cu_(0.96)GaTe_(2),which is 114%higher than the pristine CuGaTe_(2),and the average ZT is 171.4%higher.