Ternary compounds Cu3RTe3 (R=Y, Sm, and Dy): a family of new thermoelectric materials with trigonal structures.
Ternary compounds Cu3RTe3 (R=Y, Sm, and Dy): a family of new thermoelectric materials with trigonal structures.
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DOI：
10.1021/acsami.0c09918
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发表时间：
2020-08
影响因子：
9.5
通讯作者：
Tao Wang;Yifei Xiong;Hui Huang;P. Qiu;K. Zhao;Jiong Yang;J. Xiao;Xun Shi;Lidong Chen
中科院分区：
文献类型：
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作者：
Tao Wang;Yifei Xiong;Hui Huang;P. Qiu;K. Zhao;Jiong Yang;J. Xiao;Xun Shi;Lidong Chen
本文报道了一系列具有三角结构的Cu_3RTe_3（R= Y，Sm，Dy）三元化合物（R ′ 3），它们是一种有希望的中温热电材料。第一性原理计算表明Cu 3RTe 3（R= Y，Sm，Dy）化合物是具有相似能带结构和中等带隙（0.69-0.82 eV）的半导体。合成的多晶Cu 3RTe 3（R= Y，Sm和Dy）化合物具有中等的载流子浓度（0.8-2.2*1020 cm-3）和态密度有效质量（约1.1 me），产生良好的电输运性能。此外，固有的低晶格热导率，低于1 W m-1 K-1在300-900 K，起源于重的平均原子质量和大量的原子在晶胞中，观察到的Cu 3RTe 3（R= Y，Sm，和Dy）。最后，Cu 3DyTe 3在900 K时表现出0.9的峰值无量纲品质因数，这是Cu/Ag基碲化物中报道的最高品质因数。
In this work, we report a series of Cu3RTe3 (R= Y, Sm, and Dy) ternary compounds with trigonal structure (R¯3) as promising new thermoelectric materials in intermediate temperature range. First-principles calculations show Cu3RTe3 (R= Y, Sm, and Dy) compounds are semiconductors with similar band structures and moderate band gaps (0.69-0.82 eV). The synthesized polycrystalline Cu3RTe3 (R= Y, Sm, and Dy) compounds possess moderate carrier concentrations (0.8-2.2*1020 cm-3) and density-of-state effective masses (around 1.1 me), yielding decent electrical transport performance. Furthermore, intrinsically low lattice thermal conductivities, below 1 W m-1 K-1 at 300-900 K, originated from the heavy average atomic masses and large number of atoms in the unit cell, are observed for Cu3RTe3 (R= Y, Sm, and Dy). Finally, Cu3DyTe3 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.