Raman spectroscopy of CVD graphene during transfer process from copper to SiO₂/Si substrates

Raman spectrum of CVD graphene was monitored during the transfer process, from the growing copper substrate to the final silicon substrate, passing through different liquids used to dissolve copper and to clean the resulting carbon film. The position of G and 2D peaks shifted when graphene was translated on the surface of different liquids. The largest shifting was found in the case of ferric nitrate and nitric acid solutions, this result shows that the p-type character of CVD graphene is acquired when graphene is in contact with these solutions. The important finding is that the situation of graphene (strain and doping) deposited via a CVD method changes when it is translated from the original to the final substrate. (paper)