Structural, elastic, and electronic properties of chemically functionalized boron phosphide monolayer

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Two-dimensional (2D) materials offer unique properties for advanced applications.
• Surface functionalization is a key strategy to tune the mechanical and electronic characteristics of 2D systems.
• Hexagonal boron phosphide (BP) monolayer is a 2D material with potential for electronic applications.

Purpose of the Study:

• To investigate the structural, elastic, and electronic properties of hexagonal boron phosphide (BP) monolayer functionalized with Bromine (Br) and Chlorine (Cl) atoms.
• To explore the stability and mechanical isotropy of functionalized BP monolayers.
• To assess the electronic band structure and potential applications of these modified 2D materials.

Main Methods:

• First-principles calculations were employed to predict material properties.
• Phonon spectra analysis was used to confirm the stability of functionalized BP monolayers.
• Ab initio molecular dynamics simulations were performed to further validate structural stability.

Main Results:

• Surface functionalization with Br/Cl atoms transforms the planar BP monolayer into a low-buckled structure.
• All four functionalized configurations (Cl-BP-Cl, Cl-BP-Br, Br-BP-Cl, Br-BP-Br) exhibit phonon spectra indicative of stability.
• Functionalized BP monolayers display isotropic elastic properties with circular angle-dependent Young's modulus and Poisson's ratio.
• The Cl-BP-Cl configuration shows the highest stiffness, with a Young's modulus of 43.234 N m⁻¹.
• All functionalized BP monolayers are direct semiconductors with larger band gaps compared to pristine BP.

Conclusions:

• Br/Cl functionalization enhances the stability of hexagonal boron phosphide monolayers.
• The resulting materials possess desirable isotropic elastic properties suitable for mechanical applications.
• Functionalized BP monolayers exhibit tunable electronic properties, acting as direct semiconductors with increased band gaps.
• These stable, isotropic, and semiconducting functionalized BP materials are promising candidates for next-generation nanoelectromechanical devices.