The Nb₂O₅ films were successfully prepared on the quartz substrates using chemical method. Ammonium was used as a main raw material with niobic acid solution at 12 M concentration. The XRD results ensure the formation of the monoclinic crystalline structure of the niobium pentoxide. A wide optical band gap was obtained and found to be about 3.33 eV. Clear absorption in the UV region verifies wide range of the spectrum wavelength. The surface roughness measurement indicates a good uniformity and crack-free surface. The films exhibit almost constant optical conductivity irrespective of wavelength tunability.
