Porous structures have attracted considerable interest for their impact on the transport and mechanical characteristics of materials. The fabrication of porous materials, however, often involves intricate preprocessing steps and typically lacks the ability to tailor porosity with ease. In the present study, we present a straightforward method to prepare porous BiTeSe samples by employing low-pressure spark plasma sintering, with the porosity regulated by preset mass density using a modified graphite mold. This approach resulted in a substantial decrease in thermal conductivity, attributed to the introduction of pores that reduce mass density and disrupt phonon transmission. An accompanying decrease in electrical conductivity was also noted, arising from reduced carrier concentration and mobility. Despite these variations, all porous samples maintained similar levels of thermoelectric performance, with a peak of . 0.9 at 373 K. The average within the temperature range of 298–500 K remained slightly above 0.8 for all samples. Furthermore, the porous samples exhibited greatly enhanced mechanical properties. This work demonstrates a versatile and adaptable method to produce porous materials with controllable porosity, potentially applicable to other porous thermoelectric systems.

中文翻译：

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孔隙率可调热电Bi2Te2·5Se0.5的制备

多孔结构因其对材料的传输和机械特性的影响而引起了人们的极大兴趣。然而，多孔材料的制造通常涉及复杂的预处理步骤，并且通常缺乏轻松定制孔隙率的能力。在本研究中，我们提出了一种采用低压放电等离子烧结制备多孔 BiTeSe 样品的简单方法，并使用改进的石墨模具通过预设质量密度调节孔隙率。这种方法导致热导率大幅降低，这是由于引入了孔隙，降低了质量密度并破坏了声子传输。还注意到由于载流子浓度和迁移率降低而导致电导率随之降低。尽管存在这些差异，所有多孔样品仍保持相似的热电性能水平，峰值为 . 373 K 时为 0.9。所有样品在 298–500 K 温度范围内的平均值仍略高于 0.8。此外，多孔样品表现出大大增强的机械性能。这项工作展示了一种通用且适应性强的方法来生产具有可控孔隙率的多孔材料，可能适用于其他多孔热电系统。