High-Performance Mg₃Sb_2- Bi Thermoelectrics: Progress and Perspective

Area of Science:

• Materials Science
• Solid State Physics
• Nanotechnology

Background:

• Mg3Sb2-based alloys are emerging as cost-effective thermoelectric materials.
• They offer a promising alternative to commercial Bi2Te3-based alloys for near-room-temperature applications.

Purpose of the Study:

• To review the structure-property-application relationship in Mg3Sb2-xBix alloys.
• To discuss optimization strategies for enhancing thermoelectric performance.
• To outline future directions and applications.

Main Methods:

• Review of crystallographic, electronic, and phononic structure analysis.
• Discussion of band engineering via Sb/Bi alloying.
• Analysis of carrier scattering mechanisms and defect engineering.

Main Results:

• Mg3Sb2-xBix alloys demonstrate a figure of merit (zT) exceeding unity between 300-700 K.
• Optimization strategies focus on band structure, carrier scattering, and defect control.
• These alloys show potential for refrigeration and low-grade heat power generation.

Conclusions:

• Mg3Sb2-xBix alloys possess excellent thermoelectric properties, driven by their unique structural characteristics.
• Further research into optimization and engineering aspects will accelerate their practical application.
• These materials represent a significant advancement in low-cost thermoelectric technology.