Structural and optical properties of SnO nano-filler in eco-friendly PVA polymer for flexible optoelectronic applications

Polyvinyl Alcohol (PVA) has garnered significant attention in the field of flexible optoelectronics due to its unique properties. This study investigates the effect of incorporating tin oxide (SnO) nanoparticles (NPs) with various concentrations (0, 2, 3, 4, and 5 wt%) on structural, optical, and dielectric properties of PVA films synthesized via the solution casting technique. XRD analysis revealed a 28% increase in crystallite size (from 25.74 to 32.88 nm) and reduced dislocation with rising SnO content, indicating enhanced structural ordering. Scanning electron microscopy (SEM) was confirmed homogeneous nanoparticle (NP) distribution at ≤ 3 wt% but aggregation for 5 wt%. Fourier-transform infrared (FT-IR) and Raman spectroscopy were verified hydrogen bonding between SnO and PVA hydroxyl groups. Optical band gap energy was decreased systematically from 4.59 eV (pure PVA) to 4.18 eV (5 wt% SnO), confirming enhanced semiconducting behavior. Photoluminescence (PL) intensity was quenched significantly own to SnO-PVA cross-linking, with new SnO-related emission peaks emerging at 432 nm. The dispersion and the dielectric parameters were determined as functions of SnO concentrations. Nonlinear optical susceptibility (χ ⁽³⁾) and nonlinear refractive index (n₂) rushed to 48.84 × 10^-15 and 11.43 × 10^-13 esu, respectively for 5 wt% SnO film, demonstrating strong potential for nonlinear devices. These results highlight PVA/SnO films as promising candidates for flexible optoelectronics application.