Visualising structural modification of patterned graphene nanoribbons using tip-enhanced Raman spectroscopy.

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Graphene nanoribbons (GNRs) are promising materials for nanoelectronic devices.
• Characterizing the nanoscale structure and chemical composition of GNRs is crucial for device performance.
• Electron beam lithography is a common fabrication method for GNRs.

Purpose of the Study:

• To investigate the nanoscale structural modifications at the edges of GNRs.
• To identify and map nanoscale organic contaminants on GNR surfaces.
• To demonstrate the capability of tip-enhanced Raman spectroscopy (TERS) for characterizing GNRs.

Main Methods:

• Fabrication of GNRs using electron beam lithography.
• High-resolution and hyperspectral tip-enhanced Raman spectroscopy (TERS) imaging.
• TERS analysis under ambient conditions with 5 nm spatial resolution.

Main Results:

• TERS imaging revealed a 5-10 nm disordered graphene layer at the GNR edges.
• Hyperspectral TERS identified the presence of nanoscale organic contaminants on the GNRs.
• The study achieved 5 nm spatial resolution for chemical and structural analysis.

Conclusions:

• TERS is a powerful tool for nanoscale chemical and structural characterization of graphene-based devices.
• Electron beam lithography can induce structural modifications at GNR edges.
• Understanding and mitigating nanoscale contaminants is important for GNR device applications.