The unique transport properties make CuInTe emerge as a promising thermoelectric material. However, the intrinsically low carrier concentration and high lattice thermal conductivity of CuInTe limit its thermoelectric performance. In this work, firstly, we investigate the influence of excess Te on the electrical and thermal transport properties of CuInTe. The results suggest that excess Te can act as both electron acceptors and phonon scattering centers, which simultaneously optimizes the carrier concentration and impedes the propagation of high-frequency phonons. Furthermore, the substitutional Ag/Cu defects integrated with excess Te lead to a further reduction in lattice thermal conductivity. DFT calculations indicate that the substitution of Ag for Cu can reduce phonon group velocity and intensify the acoustic phonon scattering, which agrees well with our experimental data. Finally, a high value of 1.03 is obtained @840 K for sample CuAgInTe. This study demonstrates a facile but effective approach to boost the thermoelectric performance of chalcopyrite compounds.

中文翻译：

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同时调控电学和热学性能以提高 CuInTe2 的热电性能

独特的输运特性使 CuInTe 成为一种有前途的热电材料。然而，CuInTe固有的低载流子浓度和高晶格热导率限制了其热电性能。在这项工作中，我们首先研究了过量的Te对CuInTe的电和热传输性能的影响。结果表明，过量的Te可以充当电子受体和声子散射中心，同时优化载流子浓度并阻碍高频声子的传播。此外，替代的Ag/Cu缺陷与过量的Te结合导致晶格热导率进一步降低。 DFT计算表明，用Ag替代Cu可以降低声子群速度并增强声学声子散射，这与我们的实验数据非常吻合。最后，样品 CuAgInTe 在 840 K 时获得了 1.03 的高值。这项研究展示了一种简单而有效的方法来提高黄铜矿化合物的热电性能。