Effect of Thickness Variation on The Optical Properties of PVA: Ni (CH3COO)2 films

Abstract

(PVA: Ni (CH3COO)2) films with different thicknesses were prepared by casting method. The thickness of the prepared films were (15, 20and 25) µm . The optical transmission (T %)was measured in the wavelength range of (190-900) nm .The effect of thickness increasing on optical properties such as transmittance, reflectance, absorption coefficient, refractive index, extinction coefficient in addition of the Real and Imaginary Part of dielectric constant was studied. This study reveals that all these parameters affected by the increasing of the thickness, and it also found that the optical energy gap has been increased with the increasing of the thickness, but the Urbach energy was decreased with the increasing of the thickness.