Strain Tunable Thermoelectric Material: Janus ZrSSe Monolayer

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Thermoelectric (TE) materials convert heat to electricity.
• Developing efficient and tunable TE materials is crucial for energy harvesting.
• Janus ZrSSe monolayers offer a stable 2D platform for exploring novel material properties.

Purpose of the Study:

• To systematically investigate the impact of biaxial strain on the thermoelectric performance of Janus ZrSSe monolayers.
• To identify optimal strain conditions for maximizing power factor and figure of merit (ZT).
• To understand the underlying mechanisms responsible for strain-induced TE property enhancements.

Main Methods:

• First-principles calculations to determine electronic and structural properties.
• Boltzmann transport theory to simulate thermoelectric transport parameters.
• Systematic application of biaxial tensile strain to the Janus ZrSSe monolayer.

Main Results:

• Janus ZrSSe monolayers exhibit excellent stability, suitable for strain tuning.
• Biaxial strain significantly modifies the electronic structure and TE transport properties.
• Optimal tensile strain (2%) yields a high power factor (PF) of 46.36 mW m^-1 K^-2 for n-type doping at 300 K.
• Maximum ZT values of 4.41 (p-type) and 4.88 (n-type) are achieved at 6% tensile strain, significantly outperforming unstrained conditions.
• Strain enhances band degeneracy and reduces phonon relaxation time, boosting the Seebeck coefficient and thermal conductivity.

Conclusions:

• Janus ZrSSe monolayers are promising candidates for strain-tunable thermoelectric applications.
• Strain engineering offers an effective route to enhance thermoelectric efficiency.
• The findings encourage further experimental synthesis and validation of these 2D thermoelectric materials.