Wang Tao, Xiong Yifei, Huang Hui, Qiu Pengfei, Zhao Kunpeng, Yang Jiong, Xiao Jie, Shi Xun, Chen Lidong
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2020 Sep 9;12(36):40486-40494. doi: 10.1021/acsami.0c09918. Epub 2020 Aug 26.
In this work, we report a series of CuTe ( = Y, Sm, and Dy) ternary compounds with a trigonal structure (3̅) as a family of new thermoelectric materials. First-principles calculations show that CuTe ( = Y, Sm, and Dy) compounds are semiconductors with similar band structures and moderate band gaps (0.69-0.82 eV). The synthesized polycrystalline CuTe ( = Y, Sm, and Dy) compounds possess moderate carrier concentrations (0.8-2.2 × 10 cm) and density-of-state effective masses (around 1.1 ), yielding decent electrical transport performance. Furthermore, intrinsically low lattice thermal conductivities, below 1 W m K at 300-900 K, originating from the heavy average atomic masses and large number of atoms in the unit cell, are observed for CuTe ( = Y, Sm, and Dy). Finally, CuDyTe demonstrates a peak dimensionless figure of merit of 0.9 at 900 K, which is among the highest reported for the Cu/Ag-based tellurides.
在本工作中，我们报道了一系列具有三方结构（3̅）的CuTe（ = Y、Sm和Dy）三元化合物，它们是一类新型热电材料。第一性原理计算表明，CuTe（ = Y、Sm和Dy）化合物是具有相似能带结构和适中带隙（0.69 - 0.82 eV）的半导体。合成的多晶CuTe（ = Y、Sm和Dy）化合物具有适中的载流子浓度（0.8 - 2.2×10 cm）和态密度有效质量（约1.1 ），产生了良好的电输运性能。此外，由于平均原子质量较大且晶胞中原子数量众多，在300 - 900 K时，CuTe（ = Y、Sm和Dy）的本征晶格热导率较低，低于1 W m K。最后，CuDyTe在900 K时展示出0.9的峰值无量纲优值，这是基于铜/银的碲化物中报道的最高值之一。
