Raman spectroscopy and AFM study of C-12 graphene/fullerenes C-70/C-13 graphene heterostructure

摘要

In our study, we sandwiched fullerenes C-70 in between two layers of isotopically labeled graphene and studied this heterostructure by atomic force microscopy and by Raman spectroscopy. Isotope labeling was used to distinguish between the top and the bottom graphene layers in the measured Raman spectra. We analyzed the Raman maps of isotopically labeled graphene-fullerene heterostructures and described the effect of the fullerenes on graphene layers. Apart from the peak parameters obtained directly from fitting the principal Raman modes of graphene, we evaluated strain and doping in both layers employing a correlation analysis of the positions of the G and the 2D bands. Our results show that the top layer is less doped and contains less sub-micron charge inhomogeneities than the bottom layer. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim