Optical contrast spectra studies for determining thickness of stage-1 graphene-FeCl₃ intercalation compounds

Because of novel features in their structural, electronic, magnetic and optical properties, especially potential applications in nanoelectronics, the few-layer graphene intercalation compounds (FLGICs) have been intensively studied recently. In this work, the dielectric constant of the doped graphene of stage-1 FeCl₃-GIC is obtained by fitting the optical contrast spectra. And fully intercalated stage-1 FeCl₃-FLGICs were prepared by micromechanical cleavage method from graphite intercalation compounds (GICs) for the first time. Finally, we demonstrated that the thickness of stage-1 FeCl₃-GICs by micromechanical cleavage can be determined by optical contrast spectra. This method also can be used to other FLGICs, such as SbCl₅-FLGICs and AuCl₅-FLGICs, etc.