Modifying optical properties of hydrogen beam irradiated flexible PVA polymeric films

In this study, Polyvinyl alcohol (PVA) films were irradiated with hydrogen beam of fluence 8x10(17), 16x10(17), and 24x10(17) ions/cm(2) using handmade cold beam ion source. The resulting changes in the structure characteristics and functional groups of irradiated PVA films were studied using XRD and FT-IR methods respectively. In addition, the optical band gaps and Urbach energies of untreated and irradiated PVA were calculated using Tauc's equation. The tail is 1.29 eV for PVA, improved to 1.59 eV and 4.17 eV when PVA was exposed to 8x10(17) and 24x10(17) ions/cm(2), respectively. Furthermore, the parameters including refractive index, extinction coefficient, conductivities, and permittivity for untreated and treated samples have been calculated. Furthermore, the dispersion characteristics of un-irradiated and treated films are evaluated. With increasing hydrogen fluence of 8x10(17) to 24x10(17) ions/cm(2), the relaxation time is reduced from 2.75x10(-14) sec to 0.045x10(-14) sec. On the other hand, the optical susceptibility of pure and treated PVA has been calculated. The modification which induced in the optical characteristics of the irradiation films suggests these films to apply in a different uses like optoelectronics devices.