Low-temperature joining of skutterudite thermoelectric materials using Ag nanoparticles

Abstract

The successful fabrication of a CoSb₃-based skutterudite thermoelectric generator demands the presence of both a diffusion barrier layer and a low-temperature joining process. Herein, we present an approach based on the Gibbs-Thomson effect to facilitate the low-temperature joining of skutterudite compounds with Cu-Mo electrodes. We use the Ag nanoparticles for bonding the Cu-Mo electrodes to the skutterudite compounds, which have been metallized with a Co-Mo nanograined electroplated layer at temperature of 400 °C. This results in the joint strength of 15 MPa and maintaining a contact resistance of 4.16 μΩcm². The diffusion of Cu in the Ag sintering layer plays a vital role in the formation of joint. The presence of Cu-containing solid solutions between the Ag layer and the Co-Mo layer, as well as between the Ag layer and the Cu-Mo electrode, contributes to the establishment of a strong metallurgical bond between these components.