Optical Properties of Nanometer Epitaxial Nickel Oxide Films on LiNbO3 Substrates

Abstract

Nanometer epitaxial nickel oxide films have been successfully fabricated on LiNbO₃ substrates by magnetron sputtering. Optical properties of NiO films were studied in the wavelength range of 250-800 nm, and transmission and reflection spectra of these structures were simulated. The dispersion of the complex refractive index of the grown films was obtained, which ensures good agreement between the calculated and experimental transmission and reflection spectra. The band gap energy of NiO films was evaluated using Ultraviolet (UV)-visible spectroscopy. It is in the range of 3.57-3.59 eV. These studies allowed us to determine the thicknesses of the grown epitaxial films using optical methods and compare them with the results obtained based on the film growth rate and atomic force microscopy data.