Zhao Taolin, Li Xin, Wu Weiming, Gu Jialin, Han Yunze, Tang Xian
China Institute of Atomic Energy, Beijing 102413, China.
ACS Omega. 2025 Jul 7;10(28):30023-30030. doi: 10.1021/acsomega.4c10843. eCollection 2025 Jul 22.
Due to its high operating temperature and excellent mechanical properties, SiGe alloy has become a typical representative of high-temperature thermoelectric materials and has been widely utilized in radioisotope thermoelectric generators (RTGs). However, its relatively high thermal conductivity poses an obstacle to the enhancement of the ZT value, thereby significantly restricting the future development of RTGs. This study involves the fabrication of n-type (SiGe)P(SiC) alloy using high-energy ball milling followed by spark plasma sintering (SPS). Thanks to the composite effect of SiC and the SiGe matrix, nanopores were successfully introduced into the SiGe matrix. Consequently, the power factor improved while the thermal conductivity markedly decreased. The lowest thermal conductivity could be decreased to 2.08 W·m·K.The (SiGe)P(SiC) sample achieved a ZT value of 1.308 at 1023 K, with only a 2.4% reduction in thermoelectric performance after thermal aging. In summary, this paper puts forward an effective approach that can effectively improve the thermoelectric properties of SiGe alloy and delay the attenuation of these properties.
由于其较高的工作温度和优异的机械性能，硅锗合金已成为高温热电材料的典型代表，并已广泛应用于放射性同位素热电发生器（RTG）。然而，其相对较高的热导率对ZT值的提高构成了障碍，从而显著限制了RTG的未来发展。本研究涉及通过高能球磨然后进行放电等离子烧结（SPS）制备n型（硅锗）P（碳化硅）合金。由于碳化硅与硅锗基体的复合效应，纳米孔成功引入到硅锗基体中。因此，功率因数提高，而热导率显著降低。最低热导率可降至2.08W·m·K。（硅锗）P（碳化硅）样品在1023K时的ZT值达到1.308，热老化后热电性能仅降低2.4%。综上所述，本文提出了一种有效方法，可有效改善硅锗合金的热电性能并延缓这些性能的衰减。
