Evolution of the optical properties of PVA film filled with CuCl

Abstract

Polyvinyl alcohol (PVA) has been doped by different percentage of Copper Chloride (CuCl), films for different weight ratio (0, 1, 1.5, and 2%) were prepared by the well-known solution cast method. The optical properties were obtained in the wavelength range (190-1100) nm. Results show that for the pure PVA films the optical constants were increased after doping and with increasing impurity concentration. For indirect allowed transition the optical energy gap decreases from 4.6 eV (for pure PVA) to 3.8 eV (for PVA+2%CuCl).The results show the absorption edge for electrolyte samples moves toward a lower energy region by increasing the salt concentration, leading to the band gap reduction. This study shows that the optical properties of PVA are affected by salt concentration.