Exploring the optical and morphological properties of metal oxide thin films produced via reactive electron beam evaporation

We report on the development of metal oxide films with potential applications in energy conversion devices. Using an electron beam evaporator in an oxygen atmosphere, titanium, tin, nickel, molybdenum and aluminum oxides in room temperature were reactively deposited. The deposited films were characterized optically and structurally using ultraviolet-visible (UV-Vis) spectrometry, ellipsometry, X-ray photoelectron spectroscopy (XPS), contact angle and scanning electron microscopy. A systematic comparison between these filters confirmed that stacking layers with titanium dioxide (TiO2) and nickel oxide (NiO) are the best candidate for PV modules as they demonstrate higher transmission in the visible range. The morphological analysis confirms the formation of compact, uniform, and defect-free metal films, as validated by field emission scanning electron microscopy (FESEM). Additionally, contact angle measurements were conducted to assess the wettability of the metal surfaces. All oxide films exhibited semi-hydrophilic characteristics, indicating their ability to repel water from the surface and suggesting improved stability. The stoichiometry was impacted by the varying oxygen pressures at which each oxide was deposited. The transmittance of the TiO2 and NiO are more than 80% in the visible range. The results investigate potential applications as antireflection coatings, high reflectance mirrors and selective filters.