BiSbSe_1.25Te_1.75, a typical multi-layered compound, has great potential for use in the manufacture of high-efficiency thermoelectric conversion devices due to its ability to be fabricated with p–n junctions of identical chemical composition by defect engineering. However, the thermoelectric properties of n-type BiSbSe_1.25Te_1.75 remain limited due to its poor electrical transport properties. Herein, we report an effective strategy to decouple its electrical and thermal transport properties, which can be realized by simple hot deformation of BiSbSe_1.25Te_1.75. Nanoscale lamellar structures with large surface areas and strongly preferred orientation formed by preferred growth along the ab planes provide expressways for electron transport. These structures are beneficial for promoting S while maintaining high σ because the expressways will effectively reduce the sacrifice through μ_H. Meanwhile, multidimensional defects are also introduced into samples by hot deformation, evoking strong scattering locations for phonons of different frequencies. Benefiting from the decoupling of carrier–phonon transport via hot deformation, a high average ZT value of 0.53 from 323 to 550 K (∼112% increase) and a high ZT value of 0.60 at 470 K (∼107% increase) are achieved in BiSbSe_1.25Te_1.75. This work undoubtedly paves the way for the utilization of TE materials with identical chemical composition in the fabrication of well-matched p–n junctions.

中文翻译：

---

构建纳米层状高速公路和多维缺陷，实现 BiSbSe1.25Te1.75 中载流子-声子传输的解耦


BiSbSe_1.25Te_1.75 是一种典型的多层化合物，由于它能够通过缺陷工程制造具有相同化学成分的 p-n 结，因此在制造高效热电转换器件方面具有很大的潜力。然而，由于 n 型 BiSbSe_1.25Te_1.75 的电传输性能较差，其热电性能仍然有限。在此，我们报道了一种解耦其电和热传输特性的有效策略，这可以通过 BiSbSe_1.25Te_1.75 的简单热变形来实现。纳米级层状结构具有较大的表面积和沿 ab 平面的优先生长形成的强烈择优取向，为电子传输提供了高速公路。这些结构有利于在保持高 σ的同时促进 S，因为高速公路将有效减少通过 μ_H 的牺牲。同时，多维缺陷也通过热变形引入样品中，为不同频率的声子引起强烈的散射位置。得益于载流子-声子传输通过热变形的解耦，BiSbSe_1.25Te_1.75 在 323 至 550 K 时的平均 ZT 值为 0.53（∼增加 ∼112%），在 470 K 时实现了 0.60 的高 ZT 值（∼增加 107%）。这项工作无疑为利用具有相同化学成分的 TE 材料制造匹配良好的 p-n 结铺平了道路。