Realizing High Wide-Temperature-Range Thermoelectric Performance in Ga, I, and S co-doped AgSbTe₂.

Area of Science:

• Materials Science
• Solid State Physics
• Thermoelectrics

Background:

• Silver antimony telluride (AgSbTe2) is a promising thermoelectric material.
• Optimizing its thermoelectric performance is crucial for waste heat recovery applications.

Purpose of the Study:

• To enhance the thermoelectric figure of merit (ZT) of AgSbTe2.
• To improve power factor and reduce thermal conductivity through band engineering and phonon scattering.

Main Methods:

• Band engineering via Ga, I, and S doping to modify electronic band structure.
• Introduction of nanoprecipitates to induce multiscale phonon scattering.
• Characterization of thermoelectric properties including Seebeck coefficient, power factor, and thermal conductivity.

Main Results:

• Achieved a peak ZT of ≈2 at 625 K and an average ZT of 1.46.
• Optimized Seebeck coefficient (S) and power factor (PF), with a peak PF of 17.9 µW cm⁻¹ K⁻² and average PF (PFave) of 15.12 µW cm⁻².
• Significantly suppressed lattice thermal conductivity to as low as 0.31 W m⁻¹K⁻¹.

Conclusions:

• The combined band engineering and phonon scattering strategies effectively enhance AgSbTe2's thermoelectric performance.
• The optimized AgSbTe2 demonstrates significant potential for waste heat recovery and power generation in the near-room-temperature range (300-625 K).