Oxygen beam induced modifications on the structural characteristics and physico-chemical properties of PANI/ lead sulfide composite films

[Display omitted] •Modifications the PANI/PbSNPs nanocomposite films using homemade cold cathode ion source.•Utilizing the effects of oxygen irradiation on the structural, surface morphology and functional groups of PANI/PbSNPs composite films.•Studying the effect of oxygen irradiation on optical parameters including band gap, refractive indices, extinction coefficients, as well as optical conductivity.•The non-linear optical susceptibility and refractive index were gradually improved with oxygen beam.•The irradiated samples were convenient films for optoelectronic device. In this work, composite materials consisting of polyaniline with lead sulfide were fabricated by casting preparation method. Subsequently, the PANI/PbS films are irradiated with oxygen fluence 5x1016, 10x1016, and 15x1016 ions/cm2. The effects of oxygen beam on structural, surface morphology and functional chemical groups were characterized by XRD, SEM and FTIR respectively. On the other hand, the optical behaviour of pure and irradiated PANI/PbS samples was investigated by UV–vis spectroscopy. The Tauc's method was utilized to compute the optical gap and Urbach energy for pure and irradiated films. The Urbach tail is 1.66 eV for PANI/PbS, which reduced to 1.44 eV and 0.93 eV when the untreated films were exposed to 10x1016 and 15x1016 ions/cm2, correspondingly. In addition, linear optical characteristics, refractive indices, dielectric optical constants, extinction coefficients, as well as optical dielectric losses of pure and irradiated films were estimated. Furthermore, the dispersion characteristics, optical susceptibilities and refractive of the pure and irradiated samples were determined using Wemple and Di-Domenico method. With rising oxygen beam fluence from 5x1016 to 15x1016 ions/cm2, the time relaxation drop from 1.12x10-7sec to 0.92x10-7sec. The induced modifications on the optical behaviour and structural characteristics of irradiated PANI/PbS materials are providing the opportunity for using the irradiated samples in optical applications.