材料科学
热电效应
凝聚态物理
晶体缺陷
热导率
热电材料
声子
声子散射
散射
功勋
塞贝克系数
光电子学
热力学
复合材料
光学
物理
作者
Yilin Jiang,Jinfeng Dong,Hua‐Lu Zhuang,Jincheng Yu,Bogong Su,Hezhang Li,Jun Pei,Fu‐Hua Sun,Min Zhou,Haihua Hu,Jingwei Li,Zhanran Han,Bo‐Ping Zhang,Takao Mori,Jing‐Feng Li
标识
DOI:10.1038/s41467-022-33774-z
摘要
GeTe is a promising mid-temperature thermoelectric compound but inevitably contains excessive Ge vacancies hindering its performance maximization. This work reveals that significant enhancement in the dimensionless figure of merit (ZT) could be realized by defect structure engineering from point defects to line and plane defects of Ge vacancies. The evolved defects including dislocations and nanodomains enhance phonon scattering to reduce lattice thermal conductivity in GeTe. The accumulation of cationic vacancies toward the formation of dislocations and planar defects weakens the scattering against electronic carriers, securing the carrier mobility and power factor. This synergistic effect on electronic and thermal transport properties remarkably increases the quality factor. As a result, a maximum ZT > 2.3 at 648 K and a record-high average ZT (300-798 K) were obtained for Bi0.07Ge0.90Te in lead-free GeTe-based compounds. This work demonstrates an important strategy for maximizing the thermoelectric performance of GeTe-based materials by engineering the defect structures, which could also be applied to other thermoelectric materials.
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