International Journal of Scientific Research and Engineering Development

In this study, nanocomposite films based on polyvinylpyrrolidone (PVP) reinforced with bismuth oxide (Bi₂O₃) nanoparticles were successfully fabricated using the solution casting method, with filler loadings of 1.7, 3.4, and 5.1 wt.%. The optical properties of the prepared films were systematically examined. The results indicate that increasing the concentration of Bi₂O₃ nanoparticles leads to a significant increase in absorbance, attended by a corresponding decrease in optical transmittance. Furthermore, the combination of Bi₂O₃ nanoparticles significantly influences the optical band gap of the nanocomposite films. The energy gap was found to decrease from 4.8 eV for pure PVP to 3.65 eV for allowable indirect transitions, and from 4.58 eV to 3.0 eV for prohibited indirect transitions at a nanoparticle loading of 5.1 wt.%. This reduction in band gap is attributed to the formation of localized states within the polymer matrix due to nanoparticle inclusion. In addition, an increase in Bi₂O₃ content resulted in enhanced optical parameters, including the absorption coefficient, extinction coefficient, refractive index, as well as the real and imaginary parts of the dielectric constant, and optical conductivity. These findings demonstrate that PVP/Bi₂O₃ nanocomposite films exhibit improved optical performance, highlighting their strong potential for use in advanced optical and nanoscale optoelectronic applications.

Halah Mohammed Azeez,"Influence of Bi2 O3 Nanofiller on the Optical Behavior of PVP-Based Nanocomposites" International Journal of Scientific Research and Engineering Development, V9(3): Page(426-440) May-June 2026. ISSN: 2581-7175. www.ijsred.com. Published by Scientific and Academic Research Publishing.