Xie Hongyao, Li Zhi, Liu Yukun, Zhang Yinying, Uher Ctirad, Dravid Vinayak P, Wolverton Christopher, Kanatzidis Mercouri G
Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States.
J Am Chem Soc. 2023 Feb 8;145(5):3211-3220. doi: 10.1021/jacs.2c13179. Epub 2023 Jan 26.
The class I-III-VI diamondoid compounds with tetrahedral bonding are important semiconductors widely applied in optoelectronics. Understanding their heat transport properties and developing an effective method to predict the diamondoid solid solutions' thermal conductivity will help assess their impact as thermoelectrics. In this work, we investigated in detail the heat transport properties of CuGaInTe and CuAgGaTe and found that in the Ag-alloyed solid solutions, the Ag atom off-centering effect results in crystallographic distortion and extra strong acoustic-optical phonon scattering and an extremely low lattice thermal conductivity. Moreover, we integrate the alloy scattering and the off-centering effect with the crystallographic distortion parameter to develop a modified Klemens model that predicts the thermal conductivity of diamondoid solid solutions. Finally, we demonstrate that CuAgGaTe solid solutions are promising p-type thermoelectric materials, with a maximum of 1.23 at 850 K for CuAgGaTe.
具有四面体键合的I-III-VI类类金刚石化合物是广泛应用于光电子学的重要半导体。了解它们的热输运特性并开发一种有效的方法来预测类金刚石固溶体的热导率，将有助于评估它们作为热电材料的影响。在这项工作中，我们详细研究了CuGaInTe和CuAgGaTe的热输运特性，发现在含银合金固溶体中，银原子的偏心效应导致晶体畸变以及额外强烈的声光声子散射和极低的晶格热导率。此外，我们将合金散射和偏心效应与晶体畸变参数相结合，开发了一种改进的克莱门斯模型，用于预测类金刚石固溶体的热导率。最后，我们证明CuAgGaTe固溶体是有前景的p型热电材料，在850 K时，CuAgGaTe的最大值为1.23 。
