Sun Yifan, Kurosaki Ken, Imamura Tetsuya, Torata Ryusuke, Ohishi Yuji, Palaporn Dulyawich, Nachaithong Theeranuch, Pinitsoontorn Supree, Padchasri Jintara, Kidkhunthod Pinit, Suwannaruang Methus, Tanusilp Sora-At
Institute for Integrated Radiation and Nuclear Science, Kyoto University, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan.
Graduate School of Engineering, The University of Osaka, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
ACS Omega. 2025 Jul 17;10(29):32112-32121. doi: 10.1021/acsomega.5c03826. eCollection 2025 Jul 29.
High-entropy engineering provides an effective strategy to enhance thermoelectric properties through increased lattice disorder induced by multielement doping. Recent multielement doping of GeTe-based alloys have significantly improved their thermoelectric performance, yet the vast compositional space of high-entropy GeTe makes identifying optimal compositions challenging. In this work, we investigate high-entropy GeTe alloys derived from the state-of-the-art GeAgSbPbBiTe system by partially adding Au to increase elemental and structural complexity without significantly degrading the electrical properties. Transmission electron microscopy confirms the presence of nanoscale lattice distortions and stacking faults that promote mass and strain fluctuations by enhancing phonon scattering. The GeAuAgSbPbBiTe composition exhibits an ultralow lattice thermal conductivity of 0.22 W m K and achieves a maximum of 2.0 at 780 K. These findings demonstrate the effectiveness of high-entropy doping in tuning thermoelectric performance and advancing the development of next-generation GeTe-based thermoelectric materials.
高熵工程提供了一种有效的策略，通过多元素掺杂引起的晶格无序增加来提高热电性能。最近对基于GeTe的合金进行多元素掺杂显著改善了它们的热电性能，然而高熵GeTe巨大的成分空间使得确定最佳成分具有挑战性。在这项工作中，我们研究了源自最先进的GeAgSbPbBiTe系统的高熵GeTe合金，通过部分添加Au来增加元素和结构的复杂性，而不会显著降低电学性能。透射电子显微镜证实了纳米级晶格畸变和堆垛层错的存在，这些通过增强声子散射促进了质量和应变波动。GeAuAgSbPbBiTe成分表现出0.22 W m K的超低晶格热导率，并在780 K时达到最大值2.0。这些发现证明了高熵掺杂在调节热电性能和推动下一代基于GeTe的热电材料发展方面的有效性。
