非谐性
声子
玻尔兹曼方程
热电效应
凝聚态物理
材料科学
热电材料
热导率
塞贝克系数
兴奋剂
格子(音乐)
电子
物理
热力学
量子力学
复合材料
声学
作者
Shuming Zeng,Lianghui Guo,Zhijing Huang,Qian Sheng,Yinchang Zhao,Hao Huang,Geng Li,Yusong Tu
标识
DOI:10.1021/acs.chemmater.3c01907
摘要
The performance of thermoelectric (TE) materials is restricted by the coupling between electronic and phonon transport. On the basis of first-principles calculations, self-consistent phonon theory, and the Boltzmann transport equation, this study proposes a novel class of cubic weak-bonding antiperovskites, K3IX(Se & Te), which has not been synthesized thus far. These materials exhibit strong lattice anharmonicity and enable the separation of electronic and phonon transport at the atomic level. With quartic anharmonicity correction, antiperovskites K3I(Se & Te) are predicted to exhibit remarkably low lattice thermal conductivities κL. At room temperature, the calculated κL values of K3ISe and K3ITe are only 0.60 and 0.18 W m–1 K–1, respectively. Additionally, these types of materials demonstrate an anomalously weak temperature dependence of κL, approximately conforming to a power-law relationship where κL ∼ T–0.3 for K3ITe. Simultaneously, the high degeneracy and nearly flat band structure endow K3IX(Se & Te) with large power factors when doped. At 800 K, under p-type doping, the calculated ZT values of K3ISe and K3ITe can reach 1.33 and 2.61, respectively, surpassing those of the leading traditional TE materials. The results have revealed that K3IX(Se & Te) represent a promising class of TE materials exhibiting excellent performance, and the structural features that effectively decouple phonon and electron transport also offer novel perspectives for the investigation of high-performance TE materials.
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