Boosting Thermoelectric Performance in Nanocrystalline Ternary Skutterudite Thin Films through Metallic CoTe₂...

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Physics

Background:

• Thermoelectric materials offer efficient heat-to-electricity conversion.
• Metal-semiconductor nanocomposites enhance thermal and electronic transport.
• Synergistic performance is achieved by tailoring material properties.

Purpose of the Study:

• To synthesize CoTe2-CGST nanocomposite thin films.
• To investigate the impact of CoTe2 nanophase on CGST thermoelectric properties.
• To optimize thermoelectric performance through nanocomposite engineering.

Main Methods:

• Synthesis of nanocomposite thin films via composition fluctuation-induced phase separation.
• In situ growth of metallic CoTe2 nanophase within a CGST matrix during thermal annealing.
• Characterization of structural, electronic, and thermal transport properties.

Main Results:

• Ohmic-type contact formed at the CoTe2-CGST interface, increasing carrier density and electrical conductivity.
• Metallic CoTe2 phase significantly reduced lattice thermal conductivity via enhanced phonon scattering.
• CGST-7 wt. % CoTe2 nanocomposite film achieved a 2-fold enhancement in thermoelectric figure of merit (zT ~ 1.30) at 655 K.

Conclusions:

• Metal-semiconductor nanocomposites are effective for enhancing thermoelectric materials.
• CoTe2 nanophase integration in CGST boosts thermoelectric performance synergistically.
• Optimized nanocomposite design leads to substantial improvements in thermoelectric figure of merit.