In this project, aluminum doped zinc oxide thin films were deposited on glass substrate by the RF sputtering technique. The consequence of sputtered time on the structural and optical characteristics was evaluated. The optical parameter values were determined by ultra violet visible spectroscopy that the nature of optical transitions reveals direct allowed transition for all AZO thin films. Also, some physical quantities such as the Urbach tail energy, refractive index (n) in the edge of absorption and dielectric constant (ε) were reported for the AZO thin films with various sputtered time. Derivation ineffective thickness method (DITM) was employed to the optical band gap determination and transition index without any presumption about transition natural. Time of reaction plays an essential role in controlling the
