Zhang Jianqiang, Wei Ping, Zhang Huiqiang, Li Longzhou, Zhu Wanting, Nie Xiaolei, Zhao Wenyu, Zhang Qingjie
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Foshan 528000, China.
ACS Appl Mater Interfaces. 2023 May 10;15(18):22705-22713. doi: 10.1021/acsami.3c01904. Epub 2023 May 1.
Ni metal has been widely used as a barrier layer in BiTe-based thermoelectric devices, which establishes stable joints to link BiTe-based legs and electrodes. However, the Ni/BiTe joints become very fragile when the devices were exposed to high temperature, causing severe performance deterioration and even device failure. Herein, stable Ni/BiTe joints have been established by arc spraying of the Ni barrier layer on the BiTe-based alloys. The interface microstructure and contact performance including the bonding strength and contact resistivity of the arc-sprayed Ni/BiTe joints are investigated. The results indicate that, as compared with traditional Ni/BiTe joints, the arc-sprayed Ni/BiTe joints have comparably low contact resistivity while possessing a 50% higher bonding strength. Aging the joints as an exposure to high-temperature circumstances, the arc-sprayed Ni/BiTe joints exhibit much better tolerance to the thermal shock with stable bonding strength and contact resistivity. The enhanced interfacial contact performance and thermal tolerance should be attributed to the thick Ni barrier layer and interface reaction layer with good Ohmic contact. This work provides an effective strategy to establish stable joints for the BiTe-based thermoelectric devices with improved thermal stability.
镍金属已被广泛用作基于BiTe的热电器件中的阻挡层，它能建立稳定的连接以连接基于BiTe的腿状物和电极。然而，当器件暴露于高温时，Ni/BiTe接头会变得非常脆弱，导致严重的性能恶化甚至器件失效。在此，通过在基于BiTe的合金上电弧喷涂Ni阻挡层，建立了稳定的Ni/BiTe接头。研究了电弧喷涂Ni/BiTe接头的界面微观结构和接触性能，包括结合强度和接触电阻率。结果表明，与传统的Ni/BiTe接头相比，电弧喷涂的Ni/BiTe接头具有相当低的接触电阻率，同时结合强度高50%。对接头进行高温老化处理，电弧喷涂的Ni/BiTe接头在热冲击下表现出更好的耐受性，结合强度和接触电阻率稳定。界面接触性能和热耐受性的提高应归因于厚的Ni阻挡层和具有良好欧姆接触的界面反应层。这项工作为建立具有改善热稳定性的基于BiTe的热电器件的稳定接头提供了一种有效策略。
