Tetrahedral Distortion and Thermoelectric Performance of the Ag-Substituted CuInTe2 Chalcopyrite Compound
Tetrahedral Distortion and Thermoelectric Performance of the Ag-Substituted CuInTe2 Chalcopyrite Compound
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Ag取代CuInTe2黄铜矿化合物的四面体畸变和热电性能
DOI：
10.1021/acsaem.0c01867
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发表时间：
2020
影响因子：
6.4
通讯作者：
Luo Jun
中科院分区：
文献类型：
--
作者：
Wang Chenyang;Ma Quanying;Xue Huarui;Wang Qin;Luo Pengfei;Yang Jiong;Zhang Wenqing;Luo Jun
众所周知，热电材料的电子传输和热传导对结构变化非常敏感。在本文中，研究了Ag取代对Cu1–xAgxInTe2(x= 0、0.05、0.15、0.25、0.50、0.75和1.00)固溶体的晶体结构和热电性能的影响。结构分析表明，随着Ag含量的增加，晶格应变由拉应力转变为压应力，四面体畸变先减轻后加剧，不仅影响电子性能，还影响热传输性能。 Ag取代Cu导致载流子浓度和晶格热导率降低。虽然Cu1-xAgxInTe2样品的inzT值的增强主要源于晶格热导率的显着降低，但由于Ag替代而改善的电子传输性能也发挥了重要作用。结果，Cu0.75Ag0.25InTe2 在 823 K 时实现了 ~1.36 的最大 zT 值，与原始 CuInTe2 的值相比提高了 92%。我们的研究提供了结构与热电性能之间关系的初步视图，这有利于热电性能的优化。
It is known that the electronic transport and heat conduction of thermoelectric materials are very sensitive to structural changes. In this article, the effect of Ag substitution on the crystal structure and hence thermoelectric properties of Cu1–xAgxInTe2(x= 0, 0.05, 0.15, 0.25, 0.50, 0.75, and 1.00) solid solutions are investigated. The structural analysis shows that with the increasing Ag content, the lattice strain changes from tensile stress to compressive stress, and the tetrahedral distortion first relieves and then aggravates, which influences not only electronic but also thermal transport properties. The replacement of Cu by Ag results in the reduction of carrier concentration and lattice thermal conductivity. Although the enhancement inzTvalues of Cu1–xAgxInTe2samples mainly originates from the significantly reduced lattice thermal conductivity, the improved electronic transport properties due to Ag substitution also play an important role. As a result, a maximumzTvalue of ∼1.36 is achieved for Cu0.75Ag0.25InTe2at 823 K, which is a 92% improvement compared with the value of pristine CuInTe2. Our study provides a primary view of the relationship between the structure and thermoelectric performance, which is beneficial to the optimization of thermoelectric properties.