Modulated thermal conductivity of 2D hexagonal boron arsenide: a strain engineering study

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials are crucial for high-performance devices.
• Hexagonal boron arsenide (h-BAs) is a promising 2D semiconductor with graphene-like structure.
• Understanding h-BAs properties is key for material design.

Purpose of the Study:

• To investigate the mechanical, electronic, and thermal properties of monolayer h-BAs.
• To explore the effect of strain engineering on h-BAs thermal conductivity.
• To elucidate the mechanism behind strain-induced thermal conductivity enhancement.

Main Methods:

• First-principles calculations were employed to predict material properties.
• Mechanical, electronic, and thermal transport properties were simulated.
• Strain engineering was applied along different crystallographic directions.

Main Results:

• h-BAs demonstrates a high elastic modulus (260 GPa) and a direct band gap (1.0 eV).
• Pristine h-BAs has a thermal conductivity of 180.2 W m⁻¹ K⁻¹.
• A 3% strain along armchair and zigzag directions enhances thermal conductivity to 375.0 W m⁻¹ K⁻¹ and 406.2 W m⁻¹ K⁻¹, respectively.

Conclusions:

• Monolayer h-BAs possesses desirable properties for electronic applications.
• Strain engineering offers an effective route to significantly boost h-BAs thermal conductivity.
• The enhanced thermal transport is attributed to the dominance of flexural out-of-plane phonon modes.