Effect of titanium (IV) isopropoxide fillers (Ti(OiPr)4) on structural, optical, and dielectric properties of epoxy resin composites for optoelectronic devices

This study investigates the influence of titanium (IV) isopropoxide (Ti(OiPr)4) fillers on the structural, optical, and dielectric properties of epoxy resin composites, prepared via a simple and direct dispersion method. X-ray Diffraction (XRD) confirmed that filler incorporation maintains the host polymer’s amorphous structure. Crucially, increasing the Ti(OiPr)4 concentration from 0.00 wt% to 10.00 wt% significantly tuned the material’s optoelectronic response. The indirect optical bandgap (Eg) was notably reduced, decreasing from 3.624 eV for the pure resin to a minimum of 2.316 eV for the 10.00 wt% composite, which enhances UV-blocking capability. Concurrently, both the refractive index (n) and the high-frequency dielectric constant (ε_∞) increased monotonically with filler content, rising from approximately 1.74–2.42 for ε_∞. The composite also exhibited enhancements in nonlinear optical performance, showing an increase in both third-order nonlinear optical susceptibility (χ⁽³⁾) and nonlinear refractive index (n₍₂₎). Electrically, the 10.00 wt% sample demonstrated the highest AC impedance. These collective, tunable enhancements highlight the composites’ strong potential for integration into advanced optoelectronics, UV-protection coatings, and high-performance electronic devices.