Dopant induced changes in structural and optical properties of Cr3+ doped TiO2 nanoparticles

Chromium doped TiO2 nanoparticles were synthesized by sol–gel method and studied by X-ray diffraction, Raman, UV–vis and photoluminescence spectroscopy. The size distribution and composition of the material were investigated by TEM and EDAX respectively. Incorporation of Cr3+ leads to the distortion of lattice structure and creation of oxygen vacancies as revealed by XRD and Raman spectra. Crystal field splitting of Cr3+ in substituted TiO2 results in a spin allowed and spin forbidden absorption peaks arising from Fano antiresonance. Luminescence spectra give emission lines of dopant as well as of oxygen related defect centers.