Abstract
Composite films of polyvinyl alcohol/lead iodide (PVA/PbI2) were prepared with different concentrations of PbI2 using low-cost casting process. The characteristics of the prepared films were analyzed by XRD and SEM. The XRD results showed increased crystalline nature with PbI2 content and the SEM micrographs revealed homogeneous particles distribution of PbI2 within the polymer. The optical parameters of PVA/PbI2 films were measured through UV–Vis absorption-transmittance spectroscopy. The indirect energy gap for PVA was found to be 4.75 eV, while the PVA/PbI2 film with 10 wt% PbI2 showed direct transition of 2.47 eV and indirect transition of 2.15 eV. The PVA film resistivity was found to be 1.79 × 109 Ω cm in the dark and decreased to1.85 × 108 Ω cm at 7000 lux. The film resistivity was found to decrease as the PbI2 content ratio increased up to 10 wt%. The results also showed gradual increase in photo sensitivity with increasing PbI2 content ratio in the composite films. The optical properties revealed that the composite films (PVA/PbI2) could be used in different optoelectronic applications.
•Composite films of polyvinyl alcohol/lead iodide (PVA/PbI2) containing different weight ratio of PbI2 were prepared.•The structural and surface characteristics of the prepared films were analyzed by XRD and SEM.•The direct and indirect energy gap for PVA was found to be 5.18 and 4.75 eV.•The PVA/PbI2 film with 10 wt% PbI2 showed direct transition of 2.47 eV and indirect transition of 2.15 eV.•The results also showed gradual increase in photo sensitivity with increasing PbI2 content ratio in the composite films. The composite film of (PVA/PbI2) could be used in optoelectronic applications.