Cubic AgMnSbTe₃ Semiconductor with a High Thermoelectric Performance.

Area of Science:

• Materials Science
• Solid-State Chemistry
• Thermoelectrics

Background:

• Thermoelectric materials are crucial for waste heat recovery and solid-state cooling.
• Developing novel materials with high figure of merit (ZT) is essential for efficient thermoelectric devices.

Purpose of the Study:

• To synthesize and characterize a new semiconductor, AgMnSbTe3, by reacting MnTe with AgSbTe2.
• To investigate the structural, electronic, and thermoelectric properties of AgMnSbTe3.

Main Methods:

• Equimolar reaction of MnTe and AgSbTe2.
• X-ray diffraction and pair distribution function analysis for structural characterization.
• Optical band gap measurement.
• Density functional theory (DFT) calculations.
• Thermoelectric property measurements (power factor, thermal conductivity, ZT).

Main Results:

• AgMnSbTe3 crystallizes in a rock-salt NaCl structure with statistically distributed cations.
• The material is a p-type semiconductor with a narrow optical band gap of ~0.36 eV.
• DFT calculations revealed a favorable electronic band structure for thermoelectric performance.
• Ag2Te nanograins at grain boundaries showed negligible impact on hole transmission.
• Achieved a high power factor of ~12.2 μW cm⁻¹ K⁻² and ultralow lattice thermal conductivity of ~0.34 W m⁻¹ K⁻¹ at 823 K.
• Reached a peak ZT of ~1.46 at 823 K and an average ZT of ~0.87 from 400-823 K.

Conclusions:

• AgMnSbTe3 is a promising new p-type thermoelectric material.
• Its unique structure and electronic properties contribute to high thermoelectric performance.
• The material demonstrates potential for efficient thermoelectric energy conversion.