Enhanced the Structural, Dielectric Constants, and Linear/Non-linear Optical Properties of PVB/Gd2O3 Nanocomposites for Flexible Optoelectronics

This study explores the influence of different concentrations of Gd₂O₃ nanoparticles NPs (0, 0.5, 1, 2, and 3 wt%) on the structural properties, dielectric constants, and linear/non-linear optical features of PVB/Gd₂O₃ nanocomposite films. The Gd₂O₃ NPs were synthesized using the co-precipitation method, and PVB/Gd₂O₃ nanocomposite films were produced using solution casting. XRD and FTIR spectra confirmed the successful synthesis of PVB + x wt% Gd₂O₃ nanocomposites. The direct band gap for Gd₂O₃-doped PVB nanocomposites decreased from 5.14 eV to 4.48 eV with increased concentrations of Gd₂O₃ NPs in PVB nanocomposites from 0 wt% to 3 wt%., respectively. Meanwhile, the value of E_U for Gd₂O₃-doped PVB nanocomposites increases from 0.714 eV for pure PVB to 1.725 eV for PVB + 3 wt% Gd₂O₃ nanocomposite. Additionally, the oscillation energy E_o enhanced from 6.8468 eV to 8.30 eV, and the dispersion energy E_d showed a higher value of 16.33 eV for PVB + 3 wt% Gd₂O₃ film compared to 7.24 eV for PVB. Furthermore, the static refractive index (n_o) was increased from 1.43 for PVB pure to 1.72 for PVB + 3 wt% Gd₂O₃ film. The static dielectric constant ε_s also enhanced from 2.05 to 2.96 with increasing the Gd₂O₃ ratio. Besides, the free carrier concentration (N/m^∗) varied between 2.26 × 10⁵⁵ Kg⁻¹.m⁻³ and 5.63 × 10⁵⁵ Kg⁻¹.m⁻³. In the same context, the nonlinear optical parameters χ⁽³⁾ increased from 4.5464 × 10⁻¹⁴ esu to 2.9247 × 10⁻¹³ esu, and the n₂ enhanced from 1.1941 × 10⁻¹² esu to 6.3996 × 10⁻¹² esu as the Gd₂O₃ concentration increases. The optical conductivity rose from 9.11 × 10⁸ S/cm² for PVB to 2.01 × 10⁹ S/cm² by adding 3%wt Gd₂O₃ NPs to PVB. Overall, the structural, dielectric constants, linear, and non-linear optical properties of PVB/Gd₂O₃ nanocomposites are candidates for flexible optoelectronic applications.