Matrix plainification leads to high thermoelectric performance in plastic Cu₂Se/SnSe composites

Area of Science:

• Materials Science
• Solid State Physics
• Nanotechnology

Background:

• Thermoelectric technology offers promising solutions for energy harvesting and thermal management.
• Developing materials with high thermoelectric performance and mechanical stability remains a challenge.

Purpose of the Study:

• To achieve exceptional thermoelectric performance and high plasticity in stable Copper Selenide/Tin Selenide (Cu2Se/SnSe) composites.
• To investigate the impact of a novel matrix plainification strategy on thermoelectric properties.

Main Methods:

• Employed a matrix plainification strategy to eliminate lattice vacancies in the Cu2Se matrix.
• Introduced quasi-coherent interfaces to induce phonon scattering.
• Incorporated high-density nanotwins to enhance plasticity.

Main Results:

• Achieved a high figure of merit (ZT) of 3.3 in a Cu2Se/5 wt.% Sn0.96Pb0.01Zn0.03Se composite.
• Demonstrated remarkable plasticity with a compressive strain of 12% due to nanotwins.
• Observed reduced lattice thermal conductivity without compromising carrier mobility.
• Enhanced carrier mobility and power factor through vacancy elimination.

Conclusions:

• The novel strategy significantly enhances thermoelectric performance and plasticity in Cu2Se/SnSe composites.
• Quasi-coherent interfaces and nanotwins are key to improved thermoelectric properties and mechanical robustness.
• The findings offer a new approach for optimizing composite semiconductors for thermoelectric applications.