Charge transfer induced excitons and nonlinear optical properties of ZnO/PEDOT:PSS nanocomposite films

In this current work, we have prepared zinc oxide (ZnO) nanorods by sol-gel method, and its composite films with a conducting polymer poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) also have been prepared by drop-casting method on the glass substrate. UV–Vis absorption and steady-state fluorescence studies revealed exciton dissociation and recombination at the interface of polymer chain and wide-bandgap semiconductor ZnO. Also, nonlinear optical properties of as-prepared nanocomposite films have been reported by employing an open aperture z-scan technique. A predominantly two-photon induced saturable absorption behavior, when excited with 532 nm, 10 ns laser pulses, appeared in nonlinear optical measurements. These results indicate that our as-synthesized composites can be useful in fabricating optical switch and saturable absorbers. [Display omitted] •Composite films were prepared consisting of ZnO and PEDOT:PSS.•Excitonic interaction affects the linear optical properties through charge transfer.•Two-photon induced saturable absorption behavior has been observed in the composites.•Enhancement of saturable absorption behavior has been studied.