Controlled Folding of Single Crystal Graphene

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Twisted bilayer graphene exhibits unique electronic, thermal, and magnetic properties due to interlayer coupling.
• Precise control over the twist angle is crucial for tuning these properties.
• Existing methods for creating twisted bilayer graphene often lack scalability or precise angle control.

Purpose of the Study:

• To develop a scalable method for preparing folded graphene with controlled twist angles.
• To enable the fabrication of twisted bilayer graphene with defined stacking orientations.
• To explore the potential of this technique for other 2D nanomaterials.

Main Methods:

• Graphene growth on a copper (Cu(111)) substrate.
• Utilizing a tailored substrate with distinct hydrophobic and hydrophilic regions.
• Controlled film delamination from the hydrophilic region to induce folding.
• Characterization of folded graphene structures and determination of twist angles.

Main Results:

• Successful fabrication of macroscopic folded graphene sheets with millimeter-scale uniformity.
• Creation of multiple folded sheets with defined twist angles between layers.
• Demonstration of a technique to control stacking orientation in twisted bilayer graphene.
• Identification of the relationship between fold angle and twist angle.

Conclusions:

• A novel and scalable method for producing folded graphene with controlled twist angles has been established.
• This technique allows for the precise preparation of twisted bilayer graphene with defined orientations.
• The method holds promise for the controlled fabrication of other folded 2D nanomaterials.