Thermoelectric generators (TEGs) offer a promising solution for converting waste heat into electrical energy, addressing global energy challenges with their ability to operate without moving parts and under diverse environmental conditions. However, the adoption of TEGs is limited by the drawbacks of traditional materials like bismuth telluride, which are expensive and environmentally hazardous. Silicon-based TEGs, while abundant and compatible with semiconductor manufacturing, are characterized by low thermoelectric efficiency due to high thermal conductivity and complex fabrication. In this study, we explore the possibility to use nanoporous silicon, fabricated through a metal-assisted chemical etching (MACE) method, as a novel material for TEGs. Our hypothesis was that nanoporous structures would reduce thermal conductivity and enhance the Seebeck coefficient, thereby improving the figure of merit (ZT). Additionally, a spin-on dopant (SOD) technique was used to improve the contact resistance, and further enhance the device’s performance. This research presents the synthesis and detailed characterization of nanoporous silicon, with a focus on optimizing porosity and layer thickness. The effects of SOD treatment on the electrical properties are also evaluated. The fabricated nanoporous silicon-based micro-TEGs exhibited ZT values that were 4.2 times higher for n-type and 12.4 times larger for p-type compared to bulk silicon, achieving a maximum power density of 1.12 μW/cm2. This performance significantly surpassed that of bulk silicon devices. These findings demonstrated the potential of nanoporous silicon as a viable material for next-generation thermoelectric applications, offering a scalable and more environmentally friendly alternative to traditional thermoelectric materials.

中文翻译：

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使用金属辅助化学蚀刻法形成的纳米多孔硅的热电发电机


热电发电机 （TEG） 为将余热转化为电能提供了一种很有前途的解决方案，凭借其在没有移动部件和各种环境条件下运行的能力，解决了全球能源挑战。然而，TEG 的采用受到碲化铋等传统材料的缺点的限制，这些材料价格昂贵且对环境有害。硅基 TEG 虽然丰富且与半导体制造兼容，但由于导热系数高且制造复杂，其特点是热电效率低。在这项研究中，我们探索了使用通过金属辅助化学蚀刻 （MACE） 方法制造的纳米多孔硅作为 TEG 的新型材料的可能性。我们的假设是纳米多孔结构会降低热导率并提高塞贝克系数，从而提高品质因数 （ZT）。此外，还使用了旋装式掺杂剂 （SOD） 技术来提高接触电阻，并进一步增强器件的性能。本研究介绍了纳米多孔硅的合成和详细表征，重点是优化孔隙率和层厚。还评估了 SOD 处理对电气性能的影响。与块状硅相比，制造的纳米多孔硅基微 TEG 的 ZT 值是 n 型的 4.2 倍，p 型的 ZT 值高 12.4 倍，最大功率密度为 1.12 μW/cm2。这一性能明显超过了体硅器件。 这些发现证明了纳米多孔硅作为下一代热电应用的可行材料的潜力，为传统热电材料提供了一种可扩展且更环保的替代品。