Optical investigations of poly (vinyl alcohol) doping with cobalt nitrate thin films

In current study, thin films of Poly (vinyl alcohol) doped with cobalt nitrate at volumetric ratio of (0.1-0.3) % where prepared using casting method at room temperature and then some optical properties using spectrometer (190-1100nm) were recorded. Effect of cobalt nitrate dopant on the optical parameters was studied involving refractive index, extinction coefficient and determine the optical energy gap, whereon clarified that the indirect energy gap values were around (2.15-2.25eV) depending on the doping. Also, both real and imaginary parts of dielectric constant, the width of tails, Finesse coefficient, critical angle and Brewster angle were computed.