We have used spatially resolved micro Raman spectroscopy to map the full width at half maximum (FWHM) of the graphene G-band and the 2D and G peak positions, for as-grown graphene on copper catalyst layers, for transferred CVD graphene and for micromechanically exfoliated graphene, in order to characterize the effects of a transfer process on graphene properties. Here we use the FWHM(G) as an indicator of the doping level of graphene, and the ratio of the shifts in the 2D and G bands as an indicator of strain. We find that the transfer process introduces an isotropic, spatially uniform, compressive strain in graphene, and increases the carrier concentration.
Microelectronic Engineering, 2014, Vol 121, p. 113-117
Comparison; Cu catalysts; CVD graphene; Exfoliated graphene; Graphene transfer; Raman mapping; Catalysts; Full width at half maximum; Raman spectroscopy; Cu-catalysts; Graphene