Abstract Recent studies have shown that SnTe is an attractive thermoelectric material, particularly after band engineering and/or all-scale hierarchical architecturing. In this study, SnTe microcrystals have been firstly synthesized by using a microwave-stimulated wet-chemical method, and then mixed with AgCl for spark plasma sintering. The crowding-out of AgCl induces all length scale hierarchical structures in the sintered SnTe-AgCl pellets, which include the point defects, dislocations, nanopores, and grain boundaries. Such hierarchical structures suppress the transport of phonons and result in a super-low lattice thermal conductivity of ~0.31 Wm−1 K−1 at 775 K in (SnTe)0.95(AgCl)0.05. Moreover, the decomposed AgCl induces cation doping to improve the electrical transport properties of the sintered pellets. Thus, a maximum figure of merit, ZT of ~0.51 at 773 K can be obtained with a composition of (SnTe)0.95(AgCl)0.05, which is 55% higher than that of the pristine SnTe. Our strategy enables to further increase the thermoelectric properties of thermoelectric materials.

中文翻译：

---

使用 AgCl 实现 SnTe 超低晶格热导率的挤出效应策略

摘要 最近的研究表明，SnTe 是一种有吸引力的热电材料，特别是在能带工程和/或全尺度分层结构之后。在这项研究中，首先使用微波刺激湿化学法合成了 SnTe 微晶，然后与 AgCl 混合进行放电等离子体烧结。AgCl 的挤出导致烧结 SnTe-AgCl 颗粒中的所有长度尺度层次结构，其中包括点缺陷、位错、纳米孔和晶界。这种分层结构抑制了声子的传输，并导致在 (SnTe)0.95(AgCl)0.05 中的 775 K 时具有 ~0.31 Wm-1 K-1 的超低晶格热导率。此外，分解的 AgCl 会引起阳离子掺杂，以改善烧结球团的电传输性能。因此，最大的品质因数，773 K 时的 ZT 约为 0.51，其成分为 (SnTe)0.95(AgCl)0.05，比原始 SnTe 的成分高 55%。我们的策略能够进一步提高热电材料的热电性能。