Qin Dandan, Shi Wenjing, Lu Yunzhuo, Cai Wei, Sui Jiehe
School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, China.
State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China.
ACS Appl Mater Interfaces. 2022 Jul 13;14(27):30901-30906. doi: 10.1021/acsami.2c07044. Epub 2022 Jun 29.
Nanocomposites have become a widely popular way to assist in the enhancement of thermoelectric performance for filled skutterudites. Herein, we unveil the distinctive effect of Si doping on the classic YbCoSb. On the one hand, the reduced Yb filling fraction is accompanied by the in-situ precipitated CoSi nanoparticles, which not only enhances the power factor in the intermediate-low temperature range but also reduces electronic thermal conductivity for decreasing the carrier concentration. On the other hand, CoSi nanoparticles intensively disrupt the phonon transport, hiding the increased lattice thermal conductivity due to reduced Yb filling fraction. Although the residual YbSb second phases have an adverse effect on the thermoelectric properties, the integration effects achieve a peak value of 1.37 at 823 K and increase by 21% for the YbCoSb/0.1Si sample.
纳米复合材料已成为一种广泛流行的方法，用于协助提高填充方钴矿的热电性能。在此，我们揭示了硅掺杂对经典YbCoSb的独特影响。一方面，Yb填充率的降低伴随着原位析出的CoSi纳米颗粒，这不仅提高了中低温范围内的功率因子，还通过降低载流子浓度降低了电子热导率。另一方面，CoSi纳米颗粒强烈干扰声子传输，掩盖了由于Yb填充率降低而增加的晶格热导率。尽管残留的YbSb第二相对热电性能有不利影响，但对于YbCoSb/0.1Si样品，综合效应在823 K时达到1.37的峰值，提高了21%。
