Screening strategy for developing thermoelectric interface materials

Area of Science:

• Materials Science
• Solid State Physics
• Energy Conversion

Background:

• Thermoelectric generators require stable interface materials for efficient energy conversion.
• Current thermoelectric interface materials (TEiMs) often lack performance stability.
• Conventional TEiM selection relies heavily on empirical, trial-and-error experimentation.

Purpose of the Study:

• To develop a predictive screening strategy for reliable thermoelectric interface materials (TEiMs).
• To identify a stable TEiM for high-performance MgAgSb-based thermoelectric devices.
• To demonstrate the efficacy of a computational approach in accelerating materials discovery.

Main Methods:

• Density functional theory (DFT) calculations for phase diagram predictions.
• Integration of phase diagram data with electrical resistivity and melting point analyses.
• Experimental fabrication and testing of thermoelectric modules using selected TEiMs.

Main Results:

• Identified MgCuSb as a reliable TEiM for MgAgSb, showing stability after prolonged high-temperature annealing.
• Achieved low interfacial contact resistivity (<1 microhm cm²) at the MgCuSb/MgAgSb junction.
• Fabricated a thermoelectric module with 9.25% conversion efficiency under a 300 K temperature gradient.

Conclusions:

• A DFT-based phase diagram screening strategy effectively identifies stable TEiMs.
• MgCuSb is a promising TEiM for high-performance thermoelectric applications.
• The developed strategy can be broadly applied to advance thermoelectric materials development.