Functionalized hexagonal boron nitride bilayers: desirable electro-optical properties for optoelectronic applications

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Hexagonal boron nitride (h-BN) is an insulating material with a wide bandgap.
• Exploring functionalization of h-BN bilayers is crucial for tuning its electronic and optical properties.
• Previous studies have not fully explored the potential of functionalized h-BN bilayers for optoelectronics.

Purpose of the Study:

• To investigate the structural, electronic, and optical properties of functionalized h-BN bilayers.
• To explore the potential of these functionalized materials for optoelectronic applications.
• To understand the impact of hydrogenation, hydrofluorination, and fluorination on h-BN bilayer properties.

Main Methods:

• Utilized PBE + G0W0 + BSE calculations for theoretical exploration.
• Analyzed phonon dispersions to assess dynamic stability.
• Investigated changes in electronic band structure and optical absorbance.

Main Results:

• Functionalization (hydrogenation, hydrofluorination, fluorination) induces sp3 bonding, forming diamane-like monolayers.
• Transformed h-BN bilayers from indirect wide-gap insulators to direct narrow-gap semiconductors.
• Achieved strong absorbance coefficients (>10^5 cm^-1) in the near-infrared and visible spectrum.
• Observed exciton binding energies exceeding 1 eV, reducing photogenerated electron-hole recombination.

Conclusions:

• Functionalized h-BN bilayers exhibit promising semiconductor properties for optoelectronics.
• The enhanced stability and optical absorption make them suitable for solar energy applications.
• These findings pave the way for novel optoelectronic devices based on h-BN bilayers.