文献类型：期刊文献

英文题名：Realizing high thermoelectric performance in GeTe through decreasing the phase transition temperature via entropy engineering

作者：Qiu, Yuting[1];Jin, Yang[2];Wang, Dongyang[2];Guan, Mengjia[3];He, Wenke[2];Peng, Shang[4,5];Liu, Ruiheng[6];Gao, Xiang[7];Zhao, Li-Dong[2]

机构：[1]Beihang Univ, Beihang Sch, Beijing 100191, Peoples R China;[2]Beihang Univ, Sch Mat Sci & Engn, Beijing 100191, Peoples R China;[3]East China Univ Sci & Technol, Minist Educ, Key Lab Ultrane Mat, Shanghai 200237, Peoples R China;[4]Wuhan Univ, Sch Phys & Technol, Ctr Electron Microscopy, Wuhan 430072, Hubei, Peoples R China;[5]Wuhan Univ, MOE Key Lab Artificial Micro & Nanostruct, Wuhan 430072, Hubei, Peoples R China;[6]Chinese Acad Sci, Shanghai Inst Ceram, Shanghai 201899, Peoples R China;[7]Center High Pressure Sci & Technol Adv Res, Beijing 100094, Peoples R China

年份：2019

卷号：7

期号：46

起止页码：26393

外文期刊名：JOURNAL OF MATERIALS CHEMISTRY A

收录：;EI(收录号：20194907783169);WOS:【SCI-EXPANDED(收录号:WOS:000501213600020)】；

基金：This work was financially supported by the National Key Research and Development Program of China (2018YFA0702100 and 2018YFB0703600), the National Natural Science Foundation of China (51571007, 51632005 and 51772012), the Beijing Natural Science Foundation (JQ18004), the Shenzhen Peacock Plan Team (KQTD2016022619565991) and the 111 Project (B17002). Dr Liu would like to thank the support from the Youth Innovation Promotion Association CAS (2019253).

语种：英文

外文关键词：Temperature - Tellurium compounds - Thermal conductivity - Entropy - Germanium alloys - Thermoelectricity - Germanium compounds - Electric power factor

摘要：Entropy engineering is one of the powerful approaches to suppress phase transitions. GeTe has a very high thermoelectric performance at relatively high temperatures, but the low structure symmetry and phase transition in the low temperature range limits its performance stability for power generation applications. Therefore, the optimized electrical transport properties of GeTe in a low temperature range are expected for improving the structural symmetry via suppressing phase transition. Herein, the phase transition temperature for GeTe was successfully decreased by introducing high entropy via continuously multiple doping; the phase transition temperature is correspondingly reduced from 660 K to 523 K. The Seebeck coefficient was enhanced by the improved structural symmetry through enhancing band effective mass while the carrier concentration is maintained in an optimum range. A record-high power factor of similar to 23 mu W cm(-1) K-2 was obtained at 300 K in the highest entropy sample. We found that the increased configurational entropy obtained by continuous, multiple doping produces short-range disordered microstructures, which lead to an ultralow lattice thermal conductivity of similar to 0.4 W m(-1) K-1. Combining the record high power factor and low thermal conductivity, a maximum ZT value of similar to 2.1 at 800 K was achieved for the highest entropy species Ge0.84In0.01Pb0.1Sb0.05Te0.997I0.003. This study provides an effective path to enhance thermoelectric performances via introducing entropy engineering.