Qu Luping, Yang Chao, Luo Yong, Du Zhengliang, Li Cong, Cui Jiaolin
School of Materials Science and Physics, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China.
School of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo 315016, China.
ACS Appl Mater Interfaces. 2022 Oct 12;14(40):45628-45635. doi: 10.1021/acsami.2c14688. Epub 2022 Oct 3.
CuSnSe (CTS) ternary chalcogenides have potential applications in thermoelectrics for they crystallize in a high-symmetry cubic structure and consist of earth-abundant and eco-friendly elements. However, the pristine CTS does not have optimal thermoelectric (TE) performance (ZT = 0.35 at ∼700 K), so further investigation is required in this regard. In this work, we propose an incorporation of InTe with a defect zinc-blende cubic structure into CTS, aiming to regulate the electronic and phonon transport mechanism simultaneously. The first-principles calculation reveals that the element In favors the residing at a vacancy site as an interstitial atom while Te at the Se site, which leads to band convergence and degeneracy, respectively. As a result, the electrical property improves with a 22% increase in the power factor (PF), and at the same time, the lattice thermal conductivity (κ) reduces to 0.31 W K m at 718 K. Synergistic engineering realizes a remarkable improvement in TE performance with the highest figure of merit (ZT) of 0.92 at 718 K. This value is ∼3 times that of the pristine CTS and stands among the highest in the CuSnSe family so far, which proves that the incorporation of InTe into CTS is a good proposal.
铜锡硒（CTS）三元硫族化合物因其结晶为高对称立方结构且由储量丰富且环保的元素组成，在热电领域具有潜在应用。然而，原始的CTS并不具备最佳的热电（TE）性能（在约700 K时ZT = 0.35），因此在这方面需要进一步研究。在这项工作中，我们提出将具有缺陷闪锌矿立方结构的InTe掺入CTS中，旨在同时调节电子和声子输运机制。第一性原理计算表明，In元素倾向于以间隙原子的形式驻留在空位处，而Te则占据Se位，这分别导致能带收敛和简并。结果，电学性能得到改善，功率因子（PF）提高了22%，同时，在718 K时晶格热导率（κ）降至0.31 W K⁻¹ m⁻¹。协同工程实现了TE性能的显著提升，在718 K时最高品质因数（ZT）达到0.92。该值约为原始CTS的3倍，是迄今为止铜锡硒家族中最高的之一，这证明将InTe掺入CTS是一个很好的方案。
