Statistical-Raman-Microscopy and Atomic-Force-Microscopy on Heterogeneous Graphene Obtained after Reduction of Graphene Oxide

TL;DR

This study combines statistical Raman microscopy and atomic-force microscopy to analyze the heterogeneity and defect distribution in graphene films derived from graphene oxide, providing a detailed visualization of quality variations.

Contribution

It introduces a combined SRM and AFM approach to rapidly assess and visualize the defect density and morphology of graphene films from graphene oxide.

Findings

Visualized defect distribution in graphene flakes

Correlated spectroscopic data with morphology

Demonstrated fast, reliable quality assessment

Abstract

Graphene oxide can be used as a precursor to graphene but the quality of graphene flakes is highly heterogeneous. Scanning-Raman-Microscopy (SRM) is used to characterize films of graphene derived from flakes of graphene oxide with an almost intact carbon framework (ai-GO). The defect density of these flakes is visualized in detail by analyzing the intensity and full-width at half-maximum of the most pronounced Raman peaks. In addition, we superimpose the SRM results with AFM images and correlate the spectroscopic results with the morphology. Furthermore, we use SRM technique to display the amount of defects in a film of graphene. Thus, an area of 250 x 250 {\my}m2 of graphene is probed with a step-size increment of 1 {\mu}m. We are able to visualize the position of graphene flakes, edges and the substrate. Finally, we alter parameters of measurement to analyze the quality of graphene fast and reliable. The described method can be used to probe and visualize the quality of graphene films.