Semiconducting Graphene on Silicon from First-Principles Calculations

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Graphene's zero band gap hinders its use in semiconductor applications.
• Integrating graphene with silicon (Si) technology is crucial for future electronics.
• Band gap engineering in graphene on Si substrates requires further theoretical investigation.

Purpose of the Study:

• To investigate the electronic properties of graphene adsorbed on Si surfaces.
• To explore band gap engineering in graphene for semiconductor applications.
• To assess the impact of surface passivation on graphene-Si interactions.

Main Methods:

• First-principles calculations were employed.
• Electronic properties of monolayer and bilayer graphene were studied.
• Graphene adsorption on clean and hydrogen-passivated Si (111)/Si (100) surfaces was simulated.

Main Results:

• Weak interaction between monolayer graphene and H-passivated Si resulted in a negligible band gap.
• Bilayer graphene on H-passivated Si exhibited a 108 meV band gap due to asymmetry.
• Strong interaction and chemical bond formation between graphene and clean Si yielded a 272 meV band gap.

Conclusions:

• Surface passivation and graphene layer number significantly influence band gap opening.
• Tailoring graphene-Si interfaces can enable semiconductor properties for electronic devices.
• These findings offer guidance for designing graphene-Si integrated electronic components.