Formation and Identification of Graphene

The graphene flakes were prepared by a micromechanical cleavage of a highly oriented pyrolytic graphite (HOPG) and were deposited on silicon substrates covered with thin films of SiO₂, ZnS or ZrO₂ of different thickness. A good adhesion and good contrast have been achieved. The films have been studied with the Raman scattering technique. In this work we present a modeling of the light beam passage through a three layer system "graphene-thin film-silicon" and a calculation of the graphene vision contrast dependence on the incident light wavelength. A refractive index and a thickness of the covering thin film were also varied in this work. As a conclusion a material being transparent in a visible spectral range with the refractive index ranging from 2 to 2.2 should be chosen for the best graphene layer contrast.