Evolution of the optical response in a nanostructured fluorine doped zinc oxide thin film

We measured a strong two-photon absorption effect in a fluorine doped ZnO thin solid film prepared by a simple and low-cost chemical spray deposition method. We carry out our transmittance experiments with a near-resonant excitation with a single beam at 445nm wavelength. By monitoring the change in temperature originated by the optical irradiation we were able to detect the participation of an important nonlinear optical absorption in the interaction. The effect of the aging time of the starting solution on the modification of photoluminescence (PL) and optical absorption exhibited by the sample was observed. We estimate that the formation of the nanostructured morphology of the thin solid films generates an enhancement in the near-resonant two-photon absorptive effect and in the PL of the zinc oxide.