Unlocking the Potential of Porous Bi₂Te₃-Based Thermoelectrics Using Precise Interface Engineering through Atomic...

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Porous thermoelectric materials reduce thermal conductivity but suffer from decreased electronic conductivity and mechanical strength.
• Interface engineering is crucial for optimizing thermoelectric performance in nanostructured materials.

Purpose of the Study:

• To develop a novel strategy for enhancing thermoelectric performance and mechanical strength in porous Bi_0.4Sb_1.6Te₃ (BST) materials.
• To overcome the limitations of reduced electronic conductivity and degraded mechanical properties in porous thermoelectric materials.

Main Methods:

• Fabrication of porous BST by selective dissolution of KCl from a BST-KCl mixture.
• Interface engineering of porous BST using atomic layer deposition (ALD) to coat with ZnO films.
• Characterization of thermal conductivity, electronic conductivity, power factor, and mechanical strength.

Main Results:

• The novel architecture significantly reduced thermal conductivity through nanopores and ZnO/BST heterointerfaces, enhancing phonon scattering.
• ZnO coating improved the power factor by mitigating high resistivity, leading to enhanced thermoelectric efficiency.
• A maximum figure of merit (zT) of approximately 1.53 was achieved between 333-353 K, with zT of 1.44 at 298 K.
• Mechanical strength was significantly enhanced, addressing a critical limitation of porous structures.

Conclusions:

• Combining porous structuring with ALD interface engineering is an effective strategy for developing high-performance thermoelectric materials.
• The developed ZnO-coated porous BST demonstrates superior thermoelectric efficiency and mechanical robustness.
• This approach offers a promising pathway for designing advanced porous thermoelectric materials with tailored properties.