Local current mapping and patterning of reduced graphene oxide.

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Graphene oxide (GO) is a promising material, but its insulating nature hinders applications.
• Developing methods to create conductive graphene from GO is crucial for electronic devices.

Purpose of the Study:

• To investigate the structural and electrical properties of graphene derived from GO.
• To demonstrate a method for patterning conductive graphene pathways on insulating GO.
• To fabricate and characterize transistors using reduced GO channels.

Main Methods:

• Utilizing conductive atomic force microscopy (C-AFM) to analyze graphene structure and electrical properties.
• Employing an AFM-tip-induced electrochemical reduction process to pattern GO.
• Fabricating and testing transistors with reduced GO channels.

Main Results:

• Uniform large currents were measured in few-layer graphene films, indicating potential as transparent electrodes.
• Electrical discontinuities (defects) in graphene were readily detected using C-AFM.
• Multilayer graphene films exhibited higher conductivity per layer compared to single layers.
• AFM-tip reduction successfully patterned conductive pathways on insulating GO.
• Transistors with reduced GO channels showed ambipolar transport and an 8-order increase in current density.

Conclusions:

• Graphene derived from GO possesses excellent electrical properties suitable for transparent electrodes.
• AFM-tip-induced reduction is an effective technique for creating conductive patterns on GO.
• Reduced GO channels enable the fabrication of high-performance transistors with tunable electronic properties.