Novel Blue-Wavelength-Blocking Contact Lens with Er³⁺/TiO₂ NPs: Manufacture and Characterization

Thermally stable titanium dioxide nanoparticles (TiO₂ NPs) doped with erbium ions (Er³⁺) are characterized by uniformity, low excitation energy, and high surface area. The impregnation methodology was used to enhance the optical properties of TiO₂ NPs impregnated with various Er³⁺ ion contents. The synthesized Er³⁺/TiO₂ samples were characterized by energy dispersive X-ray (EDX), metal mapping, UV-Visible spectrum, field emission scanning electron microscopy (FESEM), and X-ray diffraction (XRD). The Er³⁺ ions, per our findings, were well-distributed on the TiO₂ surface of the anatase phase and there was an insignificant difference in particle size, but there was no change in the particle shapes of the Er³⁺/TiO₂ NPs structure. The maximum band gap degradation occurred with 1.8 wt % of Er³⁺/TiO₂, where the energy gap degraded from 3.13 to 2.63 eV for intrinsic TiO₂. The synthesized Er³⁺/TiO₂ samples possess predominantly finely dispersed erbium ion species on the surface. Er³⁺ ions agglomeration on the surface increased with increasing ions in each sample. We found that 0.6 wt/vol % of Er⁺³/TiO₂ is the best optical coating and produced satisfying results in terms of blocking the transmittance of blue wavelength without reducing the image quality.