Reaction-Assisted Hierarchical Structuring for Enhanced Thermoelectric Performance in BiSbTe via In Situ...

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Thermoelectric materials convert heat to electricity, crucial for energy harvesting.
• Nanoparticle integration often faces challenges due to interfacial reactions during high-temperature processing.
• These reactions can degrade thermoelectric performance, necessitating complex surface modifications.

Purpose of the Study:

• To develop a reaction-assisted nanocompositing strategy for thermoelectric materials.
• To utilize in situ chemical reactions for hierarchical microstructure construction.
• To transform detrimental interfacial instability into a performance enhancement mechanism.

Main Methods:

• Spark plasma sintering of Gadolinium Cobalt (GdCo2) nanoparticles with p-type Bismuth Antimony Telluride (BiSbTe) matrix.
• Controlled decomposition of GdCo2 precursors during sintering.
• Analysis of microstructural evolution and thermoelectric property measurements.

Main Results:

• In situ reaction formed nanoscale CoTe2 precipitates and Gd-rich clusters, acting as phonon scattering centers.
• Lattice thermal conductivity was reduced by approximately 16.3%.
• Optimized composite (0.35 wt% GdCo2) achieved a peak thermoelectric figure of merit (zT) of ~1.30 at 350 K.

Conclusions:

• The reaction-assisted strategy offers a universal approach to enhance thermoelectric performance.
• Interfacial instability can be effectively harnessed for thermoelectric material design.
• This method provides a reliable principle for optimizing thermoelectric composites.