In2O3 synthesis and investigation of their impact on the structural and physical characteristics of polyvinyl alcohol films for optical applications

In2O3 nanoparticles were synthesized via the simple-polymerized-complex method and incorporated in the PVA matrix with different contents to obtain PVA-In2O3 films via the casting technique. The optical and structural characteristics of the synthesized PVA-In2O3 films were analyzed using Fourier transform infrared (FTIR), scanning electron microscope (SEM), UV-vis spectroscopy, and X-ray diffraction (XRD). These techniques help in understanding how the addition of In2O3 affects the PVA properties. The change in PVA's structure upon increasing the In2O3 concentration was investigated through XRD and FTIR. XRD showed the change in the crystallinity of the PVA with increasing In2O3 concentration. SEM confirms the incorporation of In2O3 in the PVA matrix in the nanoscale with the formation of aggregations at higher concentrations. The PVA's optical absorbance was investigated through the UV-visible spectrophotometer, and a change upon adding In2O3 nanoparticles was observed. The PVA's direct bandgap changed from 5.41 eV to 3.5 eV, and the indirect bandgap from 4.61 eV to 2.5 eV upon adding 8 % In2O3. Increasing In2O3 concentration in the PVA significantly enhances the refractive index and optical conductivity. These results highlight the potential of In2O3-filled PVA films for optical applications, showcasing their improved optical and structural properties.