Investigation of linear and nonlinear optical properties of amorphous carbon nanofilms prepared by electron beam evaporation

Abstract Carbon nanofilms are easier to integrate in electronic devices than their two-dimensional counterparts. With proper engineering, they can offer similar optical and electrical properties without any alteration because of material transfer effects. In the current research, amorphous carbon nanofilms with thicknesses of 2, 5 and 20 nm were prepared by electron beam evaporation onto glass substrates. The surface morphology, structural and optical properties were analyzed. Through ellipsometric analysis, the linear dielectric functions were quantified. The results confirm the presence of multiphase amorphous carbon structures in the films with different electronic hybridization. The 2 nm films which had the highest sp2/sp3 ratio exhibited a crossover wavelength at 397 nm related to epsilon near zero localization. The third-order nonlinear behavior close to this wavelength in all samples showed maximum response. Details and discussion of the preformed characterization and relation to potential applications are presented.