The backside of graphene: manipulating adsorption by intercalation

Area of Science:

• Materials Science
• Surface Science
• Condensed Matter Physics

Background:

• Graphene's properties are highly sensitive to its environment and substrate interactions.
• Controlling graphene's electronic properties is key to unlocking its application potential.
• Intercalation offers a method to modify graphene-substrate interactions.

Purpose of the Study:

• To investigate the effect of partial intercalation on graphene's electronic properties.
• To demonstrate the use of intercalation for creating spatially controlled doping patterns in graphene.
• To visualize and understand doping-induced changes in adsorbate binding energies on graphene.

Main Methods:

• Graphene growth on Iridium(111) substrate.
• Partial intercalation of graphene with Europium (Eu) or Cesium (Cs) atomic layers.
• Low-temperature scanning tunneling microscopy (LT-STM) for surface imaging and spectroscopy.
• Density functional theory (DFT) calculations for theoretical validation.

Main Results:

• Partial intercalation successfully created coexisting n-doped and slightly p-doped graphene regions.
• Distinct binding energy differences for ionic adsorbates on doped versus undoped graphene patches were observed.
• The observed binding energy differences were directly correlated with the induced graphene doping levels.

Conclusions:

• Backside intercalation is an effective strategy to pattern graphene doping.
• Spatially controlled doping significantly influences the interaction of adsorbates with graphene.
• This technique provides a pathway for designing graphene-based interfaces with tailored functionalities.