Oxygen intercalation in PVD graphene grown on copper substrates: A decoupling approach

Area of Science:

• Materials Science
• Surface Science
• Nanotechnology

Background:

• Graphene grown on copper (Cu) substrates exhibits strong interaction, hindering its transfer.
• Achieving defect-free graphene layers often results in enhanced substrate coupling.

Purpose of the Study:

• To investigate oxygen intercalation as a method to reduce graphene-copper substrate interaction.
• To enable efficient transfer of graphene to other surfaces.

Main Methods:

• X-ray photoelectron spectroscopy (XPS) to analyze intercalation.
• Low energy electron diffraction (LEED) to study surface structure.
• Atomic force microscopy (AFM) for surface morphology.
• Theoretical simulations for electronic and structural analysis.

Main Results:

• Oxygen intercalation was confirmed at the graphene-Cu interface at 500°C.
• An atomic oxygen adlayer formed below graphene without substrate oxidation.
• Intercalation induced structural decoupling, evidenced by Raman spectroscopy.
• Surface morphology remained largely unchanged.

Conclusions:

• Oxygen intercalation is an effective strategy to weaken graphene-substrate interaction.
• This protocol facilitates the transfer of high-quality graphene to diverse substrates.
• The method offers a pathway for advanced graphene applications.