Characterization and linear/nonlinear optical properties of PVA/CS/TiO2 polymer nanocomposite films for optoelectronics applicatio

Polymer composite materials combines of polyvinyl alcohol (PVA), chitosan (CS), and titanium oxide (TiO2) were successfully synthesizing for using in optoelectronics. Successful incorporation of TiO2 into the PVA/Chitosan (PVA/CS) blend matrix has been demonstrated by XRD, AFM, FTIR and SEM. The TiO2 is uniformly loaded and distributed in polymer chain, as seen by SEM and AFM images. Using UV–Vis optical spectroscopy, we determine the absorption coefficient, band edge, carbon clusters numbers, and Urbach energy. The effects of TiO2 on linear/nonlinear optical characteristics were investigated. The band gap of PVA/CS/TiO2 is reduced when compared to PVA/CS. However, the absorbance and optical conductivity were both increased by TiO2. After mixed PVA/CS with 2.5%, 7.5%, and 10% TiO2, the band gap energy drops from 4.99 for PVA/CS to 4.9, 4.7, and 4.23 eV, while the Urbach tail of the blend is 1.01 eV, it enhanced to 1.45 eV, 1.72 eV, and 2.07 eV respectively. The values of relaxation time
decrease gradually from 2.35 × 10–5 s to 1.11 × 10–5, 1.87 × 10–6 to 1.69 × 10–6 s as the concentration of TiO2 is raised from 2.5 to 7.5% and 10%. It has been found that incorporating TiO2 into PVA/CS enhances the synthetic composite’s optical characteristics, making the composite PVA/CS/TiO2 it suitable for use in both energy applications and optoelectronic