ψ-BCN monolayers as emerging 2D materials: effects of hydrogen passivation on structure, stability, and functionality

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Two-dimensional (2D) materials with non-hexagonal topologies offer unique electronic, optical, and mechanical properties.
• Investigating novel 2D materials is crucial for advancing next-generation technologies.

Purpose of the Study:

• To explore the structural, vibrational, electronic, and optical characteristics of hydrogenated ψ-type boron-carbon-nitride (ψ-BCN) monolayers.
• To understand the impact of site-specific hydrogen passivation on ψ-BCN properties.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Analysis included structural, vibrational (phonon dispersion), electronic (band structure), and optical (dielectric function) properties.

Main Results:

• Pristine ψ-BCN is metallic; hydrogen passivation induces distinct electronic transitions.
• Boron passivation (ψ-B_HCN) yields an indirect band gap (~0.48 eV).
• Carbon passivation (ψ-BC_HN) results in a wider indirect band gap (~3.58 eV) and shifts optical response towards isotropy.
• Nitrogen passivation (ψ-BCN_H) leads to lattice instability.
• Stable phases exhibit polarization anisotropy and localized high-frequency modes.

Conclusions:

• Lattice topology and site-specific hydrogen passivation are key determinants of ψ-BCN monolayer stability and functionality.
• Hydrogenated ψ-BCN monolayers show significant potential for advanced opto-electronic applications.