The thermoelectric transport of n-type Bi₂Te₃ heavily depends on grain alignment, causing performance limitations that severely restrict the demand for low-grade waste heat recovery. Here, the n-type Bi₂Te_2.7Se_0.3 material with a certain textured structure is prepared by an innovative rotary swaging method. It is found that various defects including Te vacancies, dislocations, and grain boundaries significantly strengthen the phonon scattering. With an obviously suppressed thermal conductivity and well-maintained carrier mobility, the obtained rods extending up to several tens of centimeters achieve a peak ZT of 1.2 at 450 K and an average ZT of 1.0 (300–550 K), with Vickers hardness and compressive strength increased to 0.42 GPa and 52.6 MPa, respectively. Moreover, the assembled 17-pair thermoelectric module achieves a competitive conversion efficiency of up to 6.3% and a high output power of 0.93 W at a temperature difference of 250 K. This study develops an effective strategy for synergistically enhancing the thermoelectric and mechanical properties of n-type Bi₂(Te,Se)₃.

中文翻译：

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创新的旋锻方法推动了 n 型 Bi2（Te， Se）3 热电技术的高性能


n 型 Bi₂Te₃ 的热电传输在很大程度上依赖于晶粒对准，导致性能限制，严重限制了对低品位余热回收的需求。在这里，通过创新的旋锻方法制备了具有一定纹理结构的 n 型 Bi₂Te_2.7Se_0.3 材料。研究发现，包括 Te 空位、位错和晶界在内的各种缺陷显著增强了声子散射。在明显抑制的热导率和保持良好的载流子迁移率的情况下，所获得的杆延伸到几十厘米，在 450 K 时达到 1.2 的峰值 ZT 和 1.0 （300-550 K） 的平均 ZT，维氏硬度和抗压强度分别增加到 0.42 GPa 和 52.6 MPa。此外，组装的 17 对热电模块在 250 K 的温差下实现了高达 6.3% 的竞争性转换效率和 0.93 W 的高输出功率。本研究开发了一种协同增强 n 型 Bi₂（Te，Se）₃ 热电和机械性能的有效策略。