Study of structural, optical, photoluminescence, dielectric, and conductivity properties of PVDF/PVP-SnO2 nanocomposites for optoelectronics and micro-supercapacitors

The structural, photoluminescence, dielectric, optical, and conductivity characteristics of polymer nanocomposites (PNCs) films made of polyvinylpyrrolidone (PVP) and poly(vinylidene fluoride) doped with tin oxide nanoparticles (SnO₂ NPs) are reported in detail in this research. Using the casting approach, PVDF/PVP films doped with SnO₂ (0.0, 0.5, 2.0, 4.0, and 7.0 wt%) were created. X-ray diffraction (XRD) study was employed to examine the effect of nanoparticles on polymer structure of the films. Using XRD data, the impact of the weight percentage of nanofiller on crystalline size and micro-strain has been investigated. XRD also ascertained the mean particle size of the SnO₂ NPs at 15 nm. The complexation and interactions between the nanofiller and the PVDF/PVP reactive groups were demonstrated by the Fourier transform infrared (FTIR) transmittance spectra. The absorbance spectra from the UV–visible spectrophotometer were used to study optical characteristics. The direct/indirect band gaps for pure blend were decreased from 5.06/4.67 eV to 4.27/3.46 eV for PVDF/PVP-4.0 wt%SnO₂ NPs, while, the values of E_U of the films increased with the adding of SnO₂ NPs in the polymer matrix. The produced nanocomposite's PL spectra were examined for optical properties, and at 430 nm, a broadened peak of the PVDF/PVP polymer was discovered. When SnO₂ nanofiller were mixed, a shift in wavelength was noticed, albeit the intensity was greatly diminished. Impedance spectroscopy has been used to examine the films' AC electrical conductivity at frequencies between 10² and 10⁷ Hz. According to Jonscher's rule, the blend's AC electrical conductivity grows as the concentration of SnO₂ NPs does. Furthermore, it has been shown that an increase in nanoparticle concentration raises the dielectric constant and composite dielectric loss. Because the 4 wt% sample has the highest AC conductivity, dielectric constant, and optical characteristics, it can be used to create flexible electrochemical devices and optoelectronic devices with improved charge-storing capacities.