Shenzhen Key Laboratory of Thermoelectric Materials and Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China.
Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, P. R. China.
Adv Mater. 2017 Oct;29(39). doi: 10.1002/adma.201703148. Epub 2017 Aug 21.
Lead telluride has long been realized as an ideal p-type thermoelectric material at an intermediate temperature range; however, its commercial applications are largely restricted by its n-type counterpart that exhibits relatively inferior thermoelectric performance. This major limitation is largely solved here, where it is reported that a record-high ZT value of ≈1.83 can be achieved at 773 K in n-type PbTe-4%InSb composites. This significant enhancement in thermoelectric performance is attributed to the incorporation of InSb into the PbTe matrix resulting in multiphase nanostructures that can simultaneously modulate the electrical and thermal transport. On one hand, the multiphase energy barriers between nanophases and matrix can boost the power factor in the entire temperature range via significant enhancement of the Seebeck coefficient and moderately reducing the carrier mobility. On the other hand, the strengthened interface scattering at the intensive phase boundaries yields an extremely low lattice thermal conductivity. This strategy of constructing multiphase nanostructures can also be highly applicable in enhancing the performance of other state-of-the-art thermoelectric systems.
碲化铅长期以来一直被认为是中温范围内理想的 p 型热电材料；然而，其商业应用在很大程度上受到其 n 型对应物的限制，后者表现出相对较差的热电性能。在这里，这个主要的局限性得到了很大的解决，据报道，在 n 型 PbTe-4%InSb 复合材料中，在 773 K 时可以实现高达 ≈1.83 的创纪录的 ZT 值。这种热电性能的显著提高归因于 InSb 掺入 PbTe 基体中，形成多相纳米结构，可同时调节电输运和热输运。一方面，纳米相与基体之间的多相能垒可以通过显著提高塞贝克系数和适度降低载流子迁移率，在整个温度范围内提高功率因子。另一方面，在密集的相界处增强的界面散射导致极低的晶格热导率。这种构建多相纳米结构的策略也可以高度适用于提高其他最先进的热电系统的性能。
