Optical properties in the UV range of a Ta2O5 inverse opal photonic crystal designed by MOCVD

The design of a tantalum oxide inverse opal-based photonic crystal with optical reflectance in the UV range is reported. A silica opal was infiltrated by tantalum(V) ethoxide to deposit Ta2O5 using a metal-organic chemical vapor deposition (MOCVD) process. The mechanism of infiltration of the precursor vapor inside the opal has been investigated. The obtained inverse opal showed a strong reflection in the UV range due to the small lattice parameter of the crystal and the high refractive index of Ta2O5. The control of this UV reflection is a step towards the full photonic bandgap in the UV–Visible which is currently the main challenge in this field.