Metallization and Diffusion Bonding of CoSb₃-Based Thermoelectric Materials

Area of Science:

• Materials Science
• Solid State Physics
• Thermoelectrics

Background:

• CoSb3-based skutterudite alloys are promising for mid-temperature thermoelectric applications.
• Effective metallization is essential for thermoelectric module performance.

Purpose of the Study:

• To develop a metallization layer and diffusion bonding method for high-performance skutterudite alloys.
• To optimize the metallization layer for enhanced thermoelectric module fabrication.

Main Methods:

• Electroplating Co-Mo layer on skutterudite alloy followed by low-temperature annealing.
• Optimizing the Co-Mo layer's thermal expansion via chemical composition control.
• Diffusion bonding of metallized skutterudite legs to Cu-Mo electrodes.

Main Results:

• Successfully fabricated a Co-Mo metallization layer with optimized thermal expansion.
• Achieved extremely low specific contact resistivity (1.41 μΩ cm²) at the Co-Mo/skutterudite interface.
• Demonstrated good thermal stability with inhibited elemental inter-diffusion (<11 µm) after prolonged annealing.

Conclusions:

• The developed Co-Mo metallization and diffusion bonding method is effective for high-performance skutterudite thermoelectric modules.
• This approach facilitates large-scale fabrication of thermoelectric devices.