Near-Field Radiative Heat Transfer between Layered β-GeSe Slabs: First-Principles Approach.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Group-IV monochalcogenides, specifically germanium selenide (GeSe) monolayers, exhibit unique anisotropic physical properties.
• While GeSe monolayers are well-studied, few-layer homostructures, approximating 2D systems, remain underexplored.
• Near-field radiative heat transfer (NFRHT) is a critical phenomenon in nanoscale thermal management.

Purpose of the Study:

• To investigate the optical properties of free-standing few-layer β-GeSe.
• To evaluate the performance of few-layer β-GeSe in near-field radiative heat transfer (NFRHT).
• To provide more realistic predictions for NFRHT between layered 2D β-GeSe materials.

Main Methods:

• Density functional theory (DFT) calculations, including spin-orbit coupling, were used to determine optical conductivity.
• Band structure and effective electron masses were calculated for up to five layers.
• Both intraband and interband transitions, along with ionic vibrations (optical phonons), were considered for optical properties.

Main Results:

• The optical conductivity of few-layer β-GeSe was calculated, incorporating electronic and vibrational contributions.
• The study analyzed intraband transitions from doping-induced free electrons and interband transitions.
• Calculations included the impact of active optical phonons on NFRHT.

Conclusions:

• The heat transfer performance of few-layer β-GeSe in NFRHT is found to be similar to that of single-layer β-GeSe.
• The inclusion of electronic and ionic contributions provides a more accurate prediction of NFRHT in layered 2D β-GeSe.
• This research highlights the potential of few-layer GeSe for NFRHT applications.