International interlaboratory comparison of Raman spectroscopic analysis of CVD-grown graphene

Published

May 20, 2022

Author(s)

Angela Hight Walker

Abstract

There is a pressing need for reliable, reproducible and accurate measurements of graphene's properties. To facilitate industrial growth, several documentary measurement standards are under development within the Nanotechnologies committees of both ISO 229 and IEC 113. Towards this effort, we report the procedure and the results of an international interlaboratory comparison (ILC) study, conducted under Versailles Project on Advanced Materials and Standards (VAMAS). This ILC focusses on the comparability of Raman spectroscopy measurements of chemical vapour deposition (CVD) grown graphene using the same measurement protocol across different institutes and laboratories. With data gathered from 17 participants across academia, industry (including instrument manufacturers) and national metrology institutes, this study investigates the measurement uncertainty contributions from both Raman spectroscopy measurements and data analysis procedures. While many of the reported Raman metrics were relatively consistent, significant and meaningful outliers occurred due to differences in both the measurements performed, instrument calibration, and data analysis. These variations ultimately resulted in inconsistent reports of peak intensity ratios, peak widths and the coverage of single-layer graphene. Due to a lack of relative intensity calibration, the relative difference in the 2D and G peak intensity ratios (2D/G) between the participants and the lead participant was up to 200%. It was also shown that the standard deviation for 2 values reported by different software packages, was 15× larger for Lorentzian fit functions than for pseudo-Voigt functions. By adopting a relative intensity calibration and consistent peak fitting and data analysis methodologies, these variations can be significantly reduced, allowing more reproducible and comparable measurements for the growing graphene industry worldwide. This project and its findings directly underpin the development of the ISO/IEC standard "DTS 21356-2 - Nanotechnologies - Structural Characterisation of CVD-grown Graphene" (Draft Technical Specification (DTS) at time of publication).

Citation

2D Materials

Volume

9

Issue

3

Pub Type

Journals

Download Paper

https://doi.org/10.1088/2053-1583/ac6cf3

Local Download

Keywords

Graphene, Raman spectroscopy, chemical vapour deposition, uncertainty, VAMAS, standardisation, interlaboratory study

Citation

Hight Walker, A. (2022), International interlaboratory comparison of Raman spectroscopic analysis of CVD-grown graphene, 2D Materials, [online], https://doi.org/10.1088/2053-1583/ac6cf3, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933776 (Accessed October 10, 2025)