Rewritable ghost floating gates by tunnelling triboelectrification for two-dimensional electronics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Electrostatic gates are crucial for controlling charges in 2D materials.
• Current methods require complex fabrication of insulators and conductors, and gates are fixed post-manufacturing.

Purpose of the Study:

• To develop a novel method for localizing and controlling electric charges in 2D materials.
• To demonstrate a dynamic and rewritable approach for creating electronic regions in 2D systems.

Main Methods:

• Utilizing triboelectric charges generated by friction with an atomic force microscope tip.
• Injecting charges through defects in graphene on a SiO2/Si substrate to create 'ghost floating gates' via tunnelling triboelectrification.
• Achieving high spatial resolution for charge localization.

Main Results:

• Demonstrated the creation, modification, and erasure of p and n regions in graphene with atomic force microscope resolution.
• Fabricated rewritable p/n+ and p/p+ junctions with feature sizes as small as 200 nm.
• Showcased the potential for dynamic control over electronic properties.

Conclusions:

• Tunnelling triboelectrification offers a unique, on-demand method for defining electronic regions in 2D materials.
• This technique paves the way for time-variant 2D electronics with adaptable conductors and doped regions.