Wide-Temperature-Range SnTe Thermoelectrics with High Average Figure of Merit

Area of Science:

• Materials Science
• Solid State Physics
• Condensed Matter Physics

Background:

• Thermoelectric materials convert heat to electricity, crucial for waste heat recovery.
• Tin telluride (SnTe) based materials show promise but require performance optimization.

Purpose of the Study:

• To enhance the thermoelectric properties of SnTe-based compounds.
• To investigate the effect of configurational entropy on band structure and thermal conductivity.

Main Methods:

• Synthesized Sn_0.87-y-zAl_0.08Sb_yMn_0.08Ag_zTe compounds with varying compositions.
• Utilized entropy engineering by increasing configurational entropy.
• Analyzed band structure, power factor, and lattice thermal conductivity.

Main Results:

• Achieved an average figure of merit (ZT) of 1.18 and a peak ZT of 1.5.
• Optimized band structure, reduced energy offset, and created a resonant level near the Fermi level.
• Significantly suppressed lattice thermal conductivity to as low as 0.30 Wm^-1K^-1 through increased phonon scattering.

Conclusions:

• Entropy engineering is an effective strategy for enhancing thermoelectric performance in SnTe-based materials.
• The approach shows potential for application in other thermoelectric material systems.
• High ZT values achieved suggest practical applications in thermoelectric power generation.