Influence of lanthanum hydroxide on the structural and optical characteristics of polystyrene films toward optoelectronic applications

Abstract

This work presents the influence and improvement of the properties of linear and non-linear optical polystyrene (PS) nanocomposites by adding lanthanum hydroxide La(OH)₃ NPs at different concentrations (0, 1, 2, and 3 wt%). The solution casting procedure was employed to fabricate the PS/La(OH)₃ nanocomposites. XRD, FTIR, SEM, EDX, and Raman spectroscopy were used to analyze the structure of the prepared samples. The pure PS film exhibits an absorption edge of 3.29 eV, which gradually decreases to 2.80, 2.39, and 2.01 eV with increasing concentrations of La(OH)₃. Additionally, the optical band gap of pure PS is 3.83 eV, respectively, decreased to 3.67, 3.55, and 3.39 eV with increasing La(OH)₃ NPs loading from 1 to 3 wt%. Furthermore, the volume and surface energy loss functions (VELF and SELF) values increased with the increasing content of La(OH)₃ NPs within the PS polymer matrix. Furthermore, the third-order nonlinear optical susceptibility χ ⁽³⁾ value increased from 1.03 × 10⁻¹⁴ for the pure PS film to 1.14 × 10⁻⁹ esu for PS/3% La(OH)₃ nanocomposite film. Meanwhile, the nonlinear refractive index n ₂ value enhanced from 2.68 × 10⁻¹³ esu for the pure PS film to 1.23 × 10⁻⁹ esu for the PS/3%La(OH)₃ nanocomposite films, respectively.