Optical properties of CVD-grown multilayer graphene on nickel using spectroscopic ellipsometry

Incorporating graphene into relevant technologies requires its integration with commercially suitable substrates. Understanding the interactions between graphene and these substrates is crucial, as graphene serves as an ideal model system for investigating electronic phenomena. In this work, we report the optical properties of multilayer graphene on nickel substrates using spectroscopic ellipsometry. We provide information on the spectral dependence of optical properties of multilayer graphene, such as the complex dielectric constant, refractive index, and optical conductivity in the energy range of 1.6-5.0 eV. The optical conductivity profile obtained from SE analysis showed a symmetrical peak at 4.38 eV, suggesting an interband transition from the pi to pi* orbital at the M point. The graphene/Ni interaction generated changes in the number of available states below the Fermi level, leading to significant changes in electron density. Our result provides the information essential for understanding relevant research and developing graphene-based optoelectronic applications.