Effect of BaWO ₄ nanoparticles on the structural and optical characteristics of the PS/BaWO ₄ nanocomposites for optical applications

This work explores the effect of BaWO 4 nanoparticles (NPs) with varying concentrations (0, 1, 2, and 3 wt%) on the structural, surface/volume energy loss functions, and linear/non-linear optical properties of polystyrene/BaWO 4 nanocomposites. The XRD pattern indicates the formation of pure BaWO 4 NPs with a tetragonal structure. SEM image revealed the uniform scroll-like shape of the synthesized BaWO 4 . The direct bandgap energy reduced from 3.88 eV in the PS film to 3.85 eV, 3.73 eV, and 3.71 eV with increasing BaWO 4 loading. Meanwhile, the Urbach energy for PS film was 1.25 eV, which rose to 1.38, 1.43, and 1.54 eV with enhanced BaWO 4 contents. In addition, the refractive index of the PS film boosted after the incorporation of BaWO 4 with a ratio of 1% and 2%wt. However, it dropped after the addition of 3% of the BaWO 4 . The optical conductivity and electrical conductivity of pristine PS improves after incorporating BaWO 4 into the PS matrix, attributable to an increase in charge transfer and a corresponding rise in the absorption coefficient. Moreover, optical parameter such as, the oscillator energy (E 0 ) and the dispersion energy (E d ), relaxation time (τ), N/m* were concluded. The oscillation frequency (ω P ) value was also found to be 0.13× 10 13 sec −1 for PS polymer, which increased to 0.23× 10 13 sec −1 and 0.34 × 10 13 sec −1 for PS/1%BaWO 4 and PS/2%BaWO 4 films, respectively, and then declined to 0.08× 10 13 sec −1 for PS/3%BaWO 4 film. The non-linear refractive index ( n 2 ), linear optical susceptibility (χ (1) ), and third-order non-linear optical susceptibility (χ (3) ) for the pristine PS and all PS/BaWO 4 nanocomposite films were derived. These results confirm that the PS/1% BaWO 4 and PS/2% BaWO 4 samples are suitable for utilization in photonic devices, anti-reflective coatings, and waveguide technology, while, the PS/3% BaWO 4 sample is employed in applications that depend on the rapid transmission of optical signals, such as optical communications.