  Graphene layers grown by chemical vapour deposition (CVD) method and
transferred from Cu-foils to the oxidized Si-substrates were investigated by
spectroscopic ellipsometry (SE), Raman and X-Ray Photoelectron Spectroscopy
(XPS) methods. The optical properties of transferred CVD graphene layers do not
always correspond to the ones of the exfoliated graphene due to the
contamination from the chemicals used in the transfer process. However, the
real thickness and the mean properties of the transferred CVD graphene layers
can be found using ellipsometry if a real thickness of the SiO2 layer is taken
into account. The pulsed layer deposition (PLD) and atomic layer deposition
(ALD) methods were used to grow dielectric layers on the transferred graphene
and the obtained structures were characterized using optical methods. The
approach demonstrated in this work could be useful for the characterization of
various materials grown on graphene.
