The vast majority of research on eco-friendly mid-temperature SnTe thermoelectrics has focused solely on improving material performance, often neglecting effective module design. Consequently, constructing high-efficiency thermoelectric devices has posed tremendous challenges. Here, we propose an innovative strategy of “ordered grain boundary reconstruction” in SnTe materials. This strategy induces a robust energy filtering effect and significantly suppresses the high-temperature bipolar diffusion. As a result, it not only enhances the power factor at higher temperatures but also reduces lattice thermal conductivity to ∼0.4 W m⁻¹ K⁻¹ at 850 K, yielding a remarkable average zT of ∼1.0 from 300 to 850 K in Sn_0.88Mn_0.12Sb_0.16Te_1.24 + 0.05Sn sample. Notably, we successfully fabricated seven pairs of devices utilizing p-type SnTe and n-type PbSe for the first time, achieving a conversion efficiency as high as ∼10.5% and an ultra-high output power density of ∼2.0 W cm⁻² at a temperature difference of 461 K. Both of these values set new records for SnTe-based devices. This work not only provides valuable insights into the extraordinary role of ordered reconstruction structures at grain boundaries, but also overcomes the technical hurdles in high-efficiency SnTe-based device fabrication, thereby paving the way for advancements in other thermoelectrics.

中文翻译：

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有序晶界重构诱导 SnTe 高效热电发电


绝大多数关于环保型中温 SnTe 热电技术的研究都只集中在提高材料性能上，而往往忽视了有效的模块设计。因此，构建高效热电器件带来了巨大的挑战。在这里，我们提出了一种在 SnTe 材料中“有序晶界重构”的创新策略。这种策略诱导了强大的能量过滤效应，并显着抑制了高温双极扩散。因此，它不仅提高了较高温度下的功率因数，而且在 850 K 时将晶格热导率降低到 ∼0.4 W ^{m-1 K-1}，在 Sn_0.88Mn_0.12Sb_0.16Te_1.24 中，从 300 到 850 K 产生 ∼1.0 的显着平均 zT ∼1.0+ 0.05Sn 样品。值得注意的是，我们首次利用 p 型 SnTe 和 n 型 PbSe 成功制造了 7 对器件，在 461 K 的温差下实现了高达 ∼10.5% 的转换效率和 ∼2.0 W ^cm-2 的超高输出功率密度。这两个值都为基于 SnTe 的设备创造了新纪录。这项工作不仅为晶界有序重建结构的非凡作用提供了宝贵的见解，而且还克服了高效基于 SnTe 的器件制造的技术障碍，从而为其他热电技术的进步铺平了道路。