Effect of UV irradiation on optical properties of pristine and MnCl2 doped PVA films

The pristine poly(vinyl alcohol) and MnCl2 doped PVA composite (PVA/MnCl2 i.e. MPVA) films were prepared by solution casting method. These were subjected to UV-irradiation for different periods of time; and the optical properties were evaluated for pre and post irradiated samples. The optical band gap was evaluated by Mott-Davis method. Direct as well as indirect band gaps of pristine PVA film were found to be 5.62 and 5.05 eV respectively; on the other hand, the same for the MnCl2 incorporated PVA composite (PVA/MnCl2) film were found to be 5.60 and 4.98 eV. The band gap of the MnCl2 doped PVA was found to be lower than that of pristine PVA film in both pre as well as post irradiated samples. It was also observed that the band gap is dependent on the irradiation time and it reduced with the time of irradiation. The optical properties like absorption coefficient, bandgaps, refractive index, and metallization criterion have been evaluated and the results and the features are discussed. (c) 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Recent Advancements in Materials science And Nanotechnology conference.

Automated summary

The optical properties of pristine poly(vinyl alcohol) and MnCl2 doped PVA composite films were studied, revealing that the band gap of MnCl2-doped PVA is lower than that of pristine PVA and is dependent on irradiation time.