Study of the effect of iodine on the optical properties of unsaturated poly Styrene (PS)

ABSTRACT<br /> In this work, the effect of iodine (I) impurities on the optical properties of (PS) thin films studied, which prepared by spin coating method on glass Substrates with thickness (40,50,60)µm at room temperature. In order to obtain the optical parameters, the transmittance and absorption spectra were recorded in the wave length rang(300-1000)nm, the optical measurements has shown that the transmittance is a function of wave length, and it is changing according to thickness of the film, at concentration 10% 0f (I) and values thickness (40,50,60)µm the measured transmittance values were (97.6%, 96.2%, 95) at waves length (660, 640, 620)nm consequently. <br /> Also the absorption coefficient (α), extinction coefficient (K˚), and reflectivity (R) as a function of photon energies for pure and doped samples for different thickness, were calculated. The results of optical measurements has shown also that the electronic transitions are indirect, the values of optical energy gap(Eg) decreases with the increasing doping concentrations of (I) for the one thickness taking the values (3.4, 3, 2.8, 1.9)ev for concentrations (0, 10%, 20%, 30%) respectively at thickness (50)µm.