Facile Morphological Qualification of Transferred Graphene by Phase-Shifting Interferometry

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Graphene transfer is crucial for fabricating graphene-based electronic circuits.
• Conventional characterization methods (Raman, AFM, TEM) are slow and complex for industrial quality control.
• There is a need for fast, reliable tools to assess transferred graphene morphology and identify defects.

Purpose of the Study:

• To evaluate phase-shifting interferometry (PSI) as a rapid, large-area characterization tool for transferred graphene.
• To compare PSI with conventional methods like Raman spectroscopy and atomic force microscopy (AFM).
• To demonstrate PSI's utility in assessing graphene surface roughness, thickness, and adhesion.

Main Methods:

• Utilized phase-shifting interferometry (PSI) for rapid, large-area (≈1 mm²) scanning of transferred graphene.
• Achieved high vertical resolution (≈0.1 nm) with PSI for detailed morphological analysis.
• Compared PSI results with conventional Raman spectroscopy and atomic force microscopy (AFM) for validation.

Main Results:

• PSI provided crucial morphological data, including surface roughness from polymer residues and graphene thickness.
• PSI demonstrated its capability to assess the adhesive strength of transferred graphene.
• PSI measurements, while sensitive to refractive indices, proved effective for characterizing transferred graphene morphology.

Conclusions:

• Phase-shifting interferometry (PSI) is a powerful, rapid tool for evaluating transferred graphene characteristics.
• PSI complements traditional methods, offering advantages in speed and area coverage for industrial and research applications.
• PSI facilitates the development of improved, defect-free graphene transfer processes.