Stable C₂N/h-BN van der Waals heterostructure: flexibly tunable electronic and optic properties

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Monolayer C2N has been successfully synthesized.
• Enhancing stability and expanding applications of C2N are key research goals.

Purpose of the Study:

• To construct a vertical van der Waals heterostructure of C2N and h-BN.
• To explore the stability, electronic, and optoelectronic properties of this heterostructure.
• To investigate the effects of strain and electric fields on the heterostructure's properties.

Main Methods:

• First-principles calculations based on density functional theory (DFT).

Main Results:

• The C2N/h-BN heterostructure exhibits a type-II band alignment, facilitating spatial separation of photo-generated electron-hole pairs.
• The heterostructure possesses a smaller direct band gap and larger band offsets, indicating excellent photoelectric and photovoltaic potential.
• Electronic properties, including the band gap, are effectively tunable via vertical strain and external electric fields.
• Compressive strain or a forward electric field can reduce the band gap while preserving the direct band gap and large band offsets.
• The heterostructure shows a wide optical absorption range and large adsorption coefficient, which can be tuned to cover near-infrared, visible, and ultraviolet regions.

Conclusions:

• The C2N/h-BN heterostructure is a promising material for advanced electronic and optoelectronic devices.
• Tunable electronic and optical properties suggest significant potential for applications in solar cells and photodetectors.
• The study provides a theoretical foundation for designing novel optoelectronic devices based on 2D materials.