Aluminum doped Zinc oxide (AZO) thin films were sputtered on glass substrates, by RF magnetron sputtering method. The prepared films are annealed in the electrical furnace at various temperatures of room temperature, 350 and 450 °C. The influence of annealing temperature on the structural, surface topography and optical properties was evaluated. The structural characteristics of AZO films were investigated by XRD and FESEM analysis. The optical values were determined by ultra violet visible spectroscopy. The band gap energy was measured by the DITM method without the need of film thickness and any presumption about transition natural. The type of optical transition, refractive index and dielectric constant at the absorption edge and their relationship with band gap energy were calculated by this method. The other optical quantities including Urbach energy, the strength of electron-phonon interaction, the penetration depth, optical density, dissipation factor, lattice dielectric constant and optical conductivity of the films were also reported. The surface topography of the samples was measured by AFM technique and its relationship was investigated with Urbach energy. The highest optical transmittance was observed in the visible range for films annealed at 350 C° which make them applicable for optoelectronic devices.
