Article ID Journal Published Year Pages File Type
10669652 Thin Solid Films 2014 6 Pages PDF
Abstract
We explore the effects of substrate, grain size, oxidation and cleaning on the optical properties of chemical vapor deposited polycrystalline monolayer graphene exploiting spectroscopic ellipsometry in the NIR-Vis-UV range. Both Drude-Lorentz oscillators' and point-by-point fit approaches are used to analyze the ellipsometric spectra. For monolayer graphene, since anisotropy cannot be resolved, an isotropic model is used. A prominent absorption peak at approximately 4.8 eV, which is a mixture of π-π* interband transitions at the M-point of the Brillouin zone and of the π-plasmonic excitation, is observed. We discuss the sensitivity of this peak to the structural and cleaning quality of graphene. The comparison with previous published dielectric function spectra of graphene is discussed giving a rationale for the observed differences.
Related Topics
Physical Sciences and Engineering Materials Science Nanotechnology
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