Optical study of Sb–S–I glass photonic crystals

• Optical spectra of Sb–S–I glass photonic crystals were presented.
• Photonic band gap of Sb–S–I inverted opals was shown.
• Refractive index was determined by filling inverted opal with various media.
• Refractive index of Sb–S–I glass in inverted opals was determined.

This work is focused on optical investigations of Sb–S–I glass photonic crystals based on three-dimensional opal template with a closed-packed face centered cubic (fcc) lattice prepared from monodisperse silicon (SiO2) spheres by gravity sedimentation. Three types of photonic structures have been examined: SiO2-opals, opals filled with Sb–S–I glass (direct opals) and Sb–S–I inverted opals obtained after removing SiO2 templates.Optical properties have been investigated by reflectance spectroscopy for wavelengths from 250 nm to 1100 nm. These measurements exhibit Bragg’s peaks connected with photonic band gap that is tunable in position and width by varying the diameter of spheres and medium filling the opal. Values of the real parts of refractive index of the Sb–S–I in the fabricated inverted opals nmed[λ ∈ (850–950) nm] = 2.42 ± 0.08 and nmed[λ ∈ (675–750) nm] = 2.39 ± 0.11 have been determined.