Effect of Cesium Aluminate Nanofiller on Optical Properties of Polyvinyl Pyrrolidone Nanocomposite Films

Abstract

The nanocomposite films of poly vinylpyrrolidone (PVP) with different amounts viz., 2, 4, 6 and 8 wt% of cesium aluminate (CsAlO2) have been fabricated using solvent casting technique. The effect of nanofiller content on the optical properties of PVP/CsAlO2 nanocomposite films has been established by UV-visible spectroscopy. The UV-visible transmittance studies revealed that the UV light absorbing nature of nanocomposite films with considerable visible transparency. The Fourier Transform Infrared (FTIR) spectral studies visualizes the effect of CsAlO2 nanofiller on the structural behaviors of PVP, while optical studies reveals an obvious change in the electronic band structure leading to a significant reduction in optical band gaps. The scanning electron microscopic (SEM) studies establish the morphological changes in PVP matrix upon doping with CsAlO2. The measured refractive index (RI) depends on the volume fraction of CsAlO2 nanofiller and the result indicates that a substantial increase of RI values from 1.85 to 2.64 at wave length 360 nm. The dielectric studies, optical conductivity measurements and Urbach energy analysis also supports the dopant dependent optical property, tuning of PVP/CsAlO2 nanocomposite films to enable effective material property engineering to suit specified application requirements.