Comparision of Optical Properties of Spun Cast Polystyrene and Iodine Doped Polystyrene Films

Abstract

In the present work the optical properties polystyrene and iodine doped polystyrene films has been studied. Thin films of polystyrene and iodine doped polysterene were deposited on glass substrates by spin coating technique at 2000 rpm for 30s. Thin films were characterized by X-ray diffraction technique to check their amorphous nature. The basic optical properties of spun cast thin films were analyzed using their transmission spectra. The related parameters i.e. oscillator strength (Eo), dispersion energy (Ed) were determined by the Wemple-Didomenico single oscillator model. The refractive index (n), extinction coefficient (k) and dielectric constants of thin films were calculated. The optical band gap was calculated by Tauc’s extrapolation and is 1.19 eV and 2.14 eV for the polystyrene and iodine doped polystyrene thin films respectively. It has been found that both optical band gap and refractive index increases with the addition of iodine.