In this paper, we reported the enhanced thermoelectric properties of Cd and Sn dual-doped Cu3SbSe4-based material prepared by the vacuum melting combined with spark plasma sintering process. X-ray photoelectron spectroscopy studies revealed the presence of Cu+, Cd2+, Sb5+, Sn4+ and Se2− states of Cu, Cd, Sb, Sn and Se, respectively. All samples exhibited p-type conduction with carrier concentrations varying from 0.54 × 1018 to 46.42 × 1018 cm−3, while carrier mobility changes from 18.2 to 46.6 cm2 V−1 s−1 at room temperature. Cd doping at Cu sites in the Cu3SbSe4 can reduce the lattice thermal conductivity, while Sn doping at Sb sites is effective to adjust the carrier concentration. The further reduction in thermal conductivity is observed in Cd-Sn co-doped samples resulting from an accumulated effect combining point defects and the secondary-phase CdSe. Consequently, the maximum dimensionless figure of merit (ZT) value reaches 0.66 at 623 K for the Cu2.75Cd0.25Sb0.94Sn0.06Se4 sample, which is 190% larger than that of the intrinsic sample (ZT of 0.35). The findings provide an alternative strategy of boosting the carrier and phonon transports of the Cu3SbSe4, which is also a meaningful guidance to achieve high performance in other copper-based chalcogenides.

中文翻译：

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具有二次相 CdSe 的 Cd 和 Sn 共掺杂 Cu3SbSe4 基复合材料的热导率降低

在本文中，我们报道了通过真空熔化结合放电等离子体烧结工艺制备的 Cd 和 Sn 双掺杂 Cu3SbSe4 基材料的增强的热电性能。X 射线光电子能谱研究表明，Cu、Cd、Sb、Sn 和 Se 分别存在 Cu+、Cd2+、Sb5+、Sn4+ 和 Se2- 态。所有样品都表现出 p 型传导，载流子浓度从 0.54 × 1018 变化到 46.42 × 1018 cm-3，而载流子迁移率在室温下从 18.2 变化到 46.6 cm2 V-1 s-1。Cu3SbSe4中Cu位的Cd掺杂可以降低晶格热导率，而Sb位的Sn掺杂可以有效调节载流子浓度。在 Cd-Sn 共掺杂样品中观察到热导率的进一步降低，这是由于点缺陷和第二相 CdSe 的累积效应导致的。因此，Cu2.75Cd0.25Sb0.94Sn0.06Se4 样品的最大无量纲品质因数 (ZT) 值在 623 K 时达到 0.66，比本征样品（ZT 为 0.35）大 190%。该发现提供了一种促进 Cu3SbSe4 的载流子和声子传输的替代策略，这也是在其他铜基硫属化物中实现高性能的有意义的指导。