SiO ₂ /TiO ₂ one-dimensional photonic crystals doped with Sm and Ce rare-earth elements for enhanced structural colors

Nowadays 1-D photonic crystal materials are becoming very popular due to their numerous innovative properties. One of the most attractive features is that they exhibit outstanding structural colors without pigment. In this study, multilayer photonic crystal with SiO ₂ /TiO ₂ architecture was grown by sol-gel technique and samarium (Sm) and cerium (Ce) elements were doped into the SiO ₂ layers. The effects of these dopants on the structural and physical properties are characterized by X-Ray Diffractometer (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscope (SEM), UV Spectrophotometer (UV–Vis) and Optic Microscope (OM) devices. Increasing concentrations of Sm and Ce dopants caused an increase in the reflectance and photonic band gap values, and increased the vitality and variety of the colors obtained on the surfaces of the coatings. Doping elements also improved the surface quality of the coatings by preventing crack formation.