Cheng Yiming, Yang Junyou, Luo Yubo, Li Wang, Vtyurin Alexander, Jiang Qinghui, Dunn Steve, Yan Haixue
State Key Laboratory of Materials Processing and Die and Mould Technology, and School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province PR China.
Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.
ACS Appl Mater Interfaces. 2022 Aug 17;14(32):37204-37212. doi: 10.1021/acsami.2c10424. Epub 2022 Aug 2.
An increasing number of studies have reported producing composite structures by combining thermoelectric and functional materials. However, combining energy filtering and ferroelectric polarization to enhance the dimensionless figure of merit thermoelectric remains elusive. Here we report a composite that contains nanostructured BaTiO embedded in a BiSbTe matrix. We show that ferroelectric BaTiO particles are evenly composited with BiSbTe grains reducing the concentration of free charge carriers with increasing BaTiO content. Additionally, as a result of the energy-filtering effect and ferroelectric polarization, the Seebeck coefficient was improved by ∼10% with a ∼10% improvement in power factors. The BaTiO phase can effectively scatters phonons reducing lattice thermal conductivity κ (0.5 W m K) and increasing to 1.31 at 363 K in BiSbTe composites with 2 vol % BaTiO content giving an improvement of ∼25% over pure BiSbTe. Our work indicates that the introduction of ferroelectric nanoparticles is an effective method for optimizing the of BiSbTe-based thermoelectric materials.
越来越多的研究报道了通过结合热电材料和功能材料来制备复合结构。然而，将能量过滤和铁电极化相结合以提高热电材料的无量纲品质因数仍然难以实现。在此，我们报道了一种包含嵌入BiSbTe基体中的纳米结构BaTiO的复合材料。我们表明，铁电BaTiO颗粒与BiSbTe晶粒均匀复合，随着BaTiO含量的增加，自由电荷载流子浓度降低。此外，由于能量过滤效应和铁电极化，塞贝克系数提高了约10%，功率因子提高了约10%。BaTiO相可有效散射声子，降低晶格热导率κ（0.5 W m K），在含2 vol% BaTiO的BiSbTe复合材料中，363 K时κ增加到1.31，比纯BiSbTe提高了约25%。我们的工作表明，引入铁电纳米颗粒是优化BiSbTe基热电材料ZT的有效方法。
