Investigation of Microstructural and Optical Properties of Ag₃O₄ Thin Films Sprayed onto Glass Substrate

In the present work we studied the effect of temperature and molarity on microstructural and optical properties of Ag₃O₄ thin films deposited by spray pyrolysis. Transparent conductive thin films of silver oxide (Ag₃O₄) were prepared by using an aqueous solution of silver nitrate (AgNO₃) and sprayed onto heated soda glass substrate at 350 °C and annealed at 550°C. X-ray diffraction showed that the films have a monoclinic structure with a preferential orientation along the (031) direction. A visible shift of the main peak as a function of temperature and solution molarity is observed. The lattice parameters a, b and c are estimated to be 3.68, 9.30 and 5.20Ǻ respectively. Scanning Electron Microscopy (SEM) analysis shows that all films are nanostructured and homogeneous with dense surfaces. Transmittance and reflectance measurements are performed in the spectral range 200-1600 nm and yielded a band gap energy (E_g) varying in the range 3.07-3.25 eV. Refractive index was studied in terms of Moss, Ravindra and Herve–Vandamme models. The optical constants such as the oscillator energy (E₀), static refractive index (n₀), dispersion energy (E_d) and dielectric parameters (ε_r ) of the films were derived from the analysis and discussed.