A Universal Raman Spectroscopic Framework for Defect Quantification in Mono-to-Multilayer Graphenic Materials: The Graphene Atlas

Abstract

Point defects, though atomically small, significantly influence the properties of 2D materials. A general method for characterizing point defect density ($n_D$) in graphenic materials with arbitrary layer number ($n_L$) is currently lacking. Here, we introduce the Graphene Atlas, a non-destructive Raman spectroscopy-based framework for defect quantification in diverse graphenic systems. We demonstrate that the relative fractions of the double-resonance D and 2D Raman bands, which arise from competing scattering processes, exhibit a universal relationship with $n_D$, independent of $n_L$. Plotting Raman data on a plane defined by defect-related and layer number-related parameters enables a direct and quantitative determination of $n_D$ and $n_L$. This Graphene Atlas provides a transformative tool for real-time defect quantification in scalable manufacturing of graphenic materials, bridging fundamental research and industrial applications. This framework establishes a new standard for defect characterization of graphenic systems, facilitating their optimization for advanced technological applications.