Comprehensive analysis of electrical, optical and structural properties of highly flexible transparent SrCeO3/PVA composite thin films

Abstract

This study presents a detailed investigation of SrCeO₃/PVA nanocomposite thin films, emphasizing their structural, optical and dielectric properties. The successful integration of SrCeO₃ nanoparticles within the Polyvinyl alcohol (PVA) matrix was confirmed through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM) and Energy dispersive x-ray analysis (EDX) revealing uniform dispersion and effective polymer-filler interactions. Crystallite size (D) is found to decrease from 72.12 nm (for 1 % SrCeO₃) to 36.07 nm (for 8 % SrCeO₃) with increase in SrCeO₃ content. Optical analysis showed enhanced UV-Visible (UV-Vis) absorption and a tunable direct band gap (2.36 eV to 3.02 eV). Dielectric studies establish a direct correlation between SrCeO₃ content and improved polarization with the 8 % SrCeO₃ film exhibiting the highest dielectric constant. Theoretical approach to understand dipolar relaxation clearly indicates the reduction in fitting parameter α from 0.8702 (for 2 % SrCeO₃) to 0.7994 (for 8 % SrCeO₃) and suppressed value of average relaxation time τ from 0.47 μs (for 2 % SrCeO₃) to 0.26 μs (for 8 % SrCeO₃). Impedance and AC conductivity further confirm the enhancement in charge mobility and reduction in resistance with higher SrCeO₃ concentrations with the fitting of the Cole-Cole relaxation model. Theoretical fittings of AC conductivity data demonstrate the enhancement in maximum barrier height (W_m) from 189.9 meV (for 1 % SrCeO₃) to 1482.8 meV (for 4 % SrCeO₃). These findings establish SrCeO₃/PVA nanocomposites as promising materials for extreme-presentation energy storage systems. This work extends valuable insights into structure-property correlations and potential future developments in nanocomposite thin films for multifunctional applications.