Determining the number of graphene layers by Raman-based Si-peak analysis
Research output: Thesis › Master's thesis › Theses
In this work, the Si-peak analysis was developed to address these fundamental limitations. It relies on the silicon peak originating from the substrate, for which the absorption relates to the number of graphene layers. The normalized Sipeak intensity is obtained simultaneously with the Raman analysis of graphene on SiO2/Si-substrate. Model was tested using pristine graphene on 285 nm and 365 nm oxide, bare 0-400 nm oxide and random stacking. The calculated number of layers agreed with the thickness references and were insensitive to graphene properties unlike other tested Raman-based methods. Model was also robust against random stacking, even near the resonant rotational angle, where graphene Raman band changes become difficult to predict. The Si-peak analysis, being virtually immune to variation within graphene, is a promising non-destructive widely applicable method to determine the number of even arbitrarily stacked graphene layers up to 100.
- graphene, Raman spectroscopy, number of layers, thickness, Si-peak