High Thermoelectric Performance in Hexagonal 2D PdTe₂ Monolayer at Room Temperature

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Recent fabrication of hexagonal palladium ditelluride (PdTe2) monolayer.
• Exploration of novel thermoelectric materials is crucial for energy conversion technologies.

Purpose of the Study:

• Investigate and compare the thermoelectric properties of hexagonal and pentagonal PdTe2 structures.
• Evaluate the potential of these materials for energy applications.

Main Methods:

• Utilized two theoretical approaches to calculate thermoelectric properties.
• Applied the Wiedemann-Franz law and Boltzmann transport equation for electronic thermal conductivity.
• Calculated the figure of merit (ZT) for both structures.

Main Results:

• Hexagonal PdTe2 has an indirect band gap of 0.17 eV; pentagonal PdTe2 has an indirect band gap of 1.18 eV.
• Initial calculations using Wiedemann-Franz law suggested ZT > 3, but this method underestimated electronic thermal conductivity.
• Boltzmann transport equation revealed a ZT of 0.8 for both structures at 300 K.
• Pentagonal PdTe2 exhibited better thermoelectric performance at temperatures above 500 K.

Conclusions:

• Hexagonal PdTe2 is a potential high-performance thermoelectric material at room temperature.
• Pentagonal PdTe2 shows promise for high-temperature thermoelectric applications.
• Accurate calculation of electronic thermal conductivity is essential for reliable ZT evaluation.