Investigation of optical and electrical properties of TiO2, SiO2, and Ag single and multilayer thin films using spectroscopic ellipsometry and spectrophotometry methods: prepared by spin coating and DC magnetron sputtering

Abstract

In this work, spectroscopic ellipsometry was used to study the optical and electrical properties of TiO2 and SiO2 thin films deposited by spin-coating at different coating rotation speeds and annealed at various temperatures. In addition, Ag thin films of different thicknesses were deposited by DC magnetron sputtering at ambient temperature. In this method, the optical band gap for TiO2 thin films is between 3.15–3.85 eV, and for SiO2 thin films, it is between 3.2–3.8 eV. The optical properties, including reflectance, transmittance, and absorbance, of TiO2, SiO2, and Ag thin films in the form of single and multilayer thin films in the wavelength range of 200–2500 nm, were investigated using an ultraviolet-visible-near infrared (UV–vis-NIR) dual-beam spectrophotometer. In the TiO2/Ag/SiO2 multilayer thin film, the rejection was 58.6% −73.6% in the NIR wavelength range (800–2500 nm), and a transmittance of 40%–45% was achieved in the visible light range (400–700 nm).