Physical modifications of polyvinyl alcohol films containing CoCl 2

Polyvinyl alcohol (PVA) films containing CoCl2 have been successfully prepared by the casting method. X-ray diffraction showed that the crystalline nature of the samples decreases with increasing the concentration of CoCl2 . Vis-UV spectra show that transmittance spectra of PVA doped with CoCl2 decrease with CoCl2 content and confirm the amorphous behavior detected by XRD patterns for high concentration of CoCl2 . UV absorption shows that the value of indirect band gap decreases with CoCl2 content. For low CoCl2 content, the value of direct band gap (Edirect) increases with decreasing the CoCl2 content. However, for high CoCl2 content, Edirect decreases with increasing the CoCl2 content. These results lead us to conclude that CoCl2 -doped PVA films are interesting for the packaging community and for photovoltaic applications.