First-principles design of g-C

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Graphitic carbon nitride (g-C3N4) and hafnium disulfide selenide (HfSSe) are promising 2D materials.
• Heterojunctions formed by stacking different 2D materials offer unique electronic and optical properties.

Purpose of the Study:

• To systematically investigate the structural, electronic, and optical properties of g-C3N4/HfSSe heterojunctions.
• To determine the stability and band alignment of different stacking configurations.
• To assess the light absorption capabilities of these heterojunctions.

Main Methods:

• First-principles calculations were employed to model the heterojunctions.
• Binding energies were calculated to assess the stability of various stacking arrangements.
• Electronic band structures and optical absorption spectra were computed.

Main Results:

• Two stable heterojunctions, g-C3N4/SHfSe and g-C3N4/SeHfS, were identified.
• Both heterojunctions exhibit direct band gaps and type II band alignment.
• Formation of a built-in electric field due to charge rearrangement at the interface.
• Excellent light absorption was predicted in the ultraviolet, visible, and near-infrared regions.

Conclusions:

• The g-C3N4/HfSSe heterojunctions are stable and possess favorable electronic properties for optoelectronic applications.
• The type II band alignment and built-in electric field are beneficial for charge separation.
• These heterojunctions demonstrate significant potential for light harvesting applications.