Determination of thickness and optical constants of solgel derived polyvinylpyrrolidone/ZrO_2 films from transmission spectra using different dispersion models

摘要

Transmission measurements have been used to investigate the optical properties of polyvinylpyrrolidone (PVP)/ZrO_2 films synthesized by the solgel route. The optical constants of PVP/ZrO_2 films deposited on quartz substrates were determined by fitting transmission spectra in the wavelength range of 200-800 nm with the Tauc-Lorentz and Cody-Lorentz physical models. Combined with Urbach tail, both models give a good description of transmission data and reveal that refractive index of film slightly decreases with increasing PVP mass fraction. X-ray reflectivity (XRR) measurements were also performed on PVP/ZrO_2 films to complement the thicknesses. The value of film thickness, including interface information from transmission spectra, is consistent with that result obtained from XRR, indicating that fitting transmission spectrum is a high reliable optical characterization.