Ultrahigh power factors in P-type 1T-ZrX₂ (X = S, Se) single layers

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Thermoelectric materials convert waste heat into electricity.
• Efficient thermoelectric materials require high electrical conductivity, Seebeck coefficient, and low thermal conductivity.
• 1T-ZrX₂ (X=S, Se) single layers are emerging candidates for thermoelectric applications.

Purpose of the Study:

• To investigate the thermoelectric properties of 1T-ZrX₂ (X=S, Se) single layers.
• To evaluate their potential for energy harvesting applications.
• To compare the performance of P-type and N-type materials.

Main Methods:

• Density functional calculations were employed to model material properties.
• Semi-classical Boltzmann transport theory was used to simulate thermoelectric performance.
• Lattice thermal conductivity was calculated to assess heat transport.

Main Results:

• P-type 1T-ZrX₂ single layers demonstrated ultrahigh power factors (PF) exceeding 11 mWm⁻²K⁻² at 300 K.
• Electronic figures of merit (ZelT) reached approximately 0.75 for P-type 1T-ZrSe₂.
• Lower lattice thermal conductivities (κph) were observed in 1T-ZrSe₂ (∼0.97 W K⁻¹m⁻¹).

Conclusions:

• P-type 1T-ZrX₂ single layers show enhanced thermoelectric performance compared to their N-type counterparts.
• The lower κph/κel ratio in P-type materials contributes to higher figures of merit (ZT).
• These findings suggest promising potential for P-type 1T-ZrX₂ in thermoelectric energy conversion.