Optical Properties of V-doped TiO2 Nanocrystals

An investigation of sol–gel synthesized pure and V-doped TiO₂ nanopowder was carried out to explore the modification of the optical properties with doping concentration. The phase presence and crystallite size as estimated by XRD and SEM is found to be changing significantly with doping. Moreover, the optical response captured by UV–Vis absorption, Raman and PL spectra demonstrated a change in band gap with increasing doping. The pure sample shows absorption over the entire measured range with a decrease in band gap as doping increases. The Raman vibration modes corresponding to anatase as well as rutile phases were detected. The PL spectra indicate a decrease in peak intensity with doping and the presence of a blue shift as doping concentration increases. The blue shift in PL for the doped sample may be due to the band tailing effect.