Zhu Yingcai, Wang Dongyang, Hong Tao, Hu Lei, Ina Toshiaki, Zhan Shaoping, Qin Bingchao, Shi Haonan, Su Lizhong, Gao Xiang, Zhao Li-Dong
School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
Nat Commun. 2022 Jul 19;13(1):4179. doi: 10.1038/s41467-022-31939-4.
Thermoelectric generators enable the conversion of waste heat to electricity, which is an effective way to alleviate the global energy crisis. However, the inefficiency of thermoelectric materials is the main obstacle for realizing their widespread applications and thus developing materials with high thermoelectric performance is urgent. Here we show that multiple valence bands and strong phonon scattering can be realized simultaneously in p-type PbSe through the incorporation of AgInSe. The multiple valleys enable large weighted mobility, indicating enhanced electrical properties. Abundant nano-scale precipitates and dislocations result in strong phonon scattering and thus ultralow lattice thermal conductivity. Consequently, we achieve an exceptional ZT of ~ 1.9 at 873 K in p-type PbSe. This work demonstrates that a combination of band manipulation and microstructure engineering can be realized by tuning the composition, which is expected to be a general strategy for improving the thermoelectric performance in bulk materials.
热电发电机能够将废热转化为电能，这是缓解全球能源危机的有效途径。然而，热电材料的低效率是实现其广泛应用的主要障碍，因此开发具有高热电性能的材料迫在眉睫。在此，我们表明，通过掺入AgInSe，在p型PbSe中可以同时实现多个价带和强声子散射。多个能谷实现了大的加权迁移率，表明电学性能得到增强。大量纳米级沉淀和位错导致强声子散射，从而实现超低晶格热导率。因此，我们在p型PbSe中于873 K时实现了约1.9的优异ZT值。这项工作表明，通过调整成分可以实现能带调控和微观结构工程的结合，这有望成为提高块体材料热电性能的通用策略。
