Abstract—Thin films of TiO₂ are deposited by Successive Ionic Layer Adsorption and Reaction (SILAR) technique. Films are characterized by X-ray diffraction, Scanning Electron Microscopy and UV-Vis. spectrometry. TiO₂ films are sensitized by the natural dye extracted from Clitoris Ternatea. Effect of dye sensitization on the optical properties of TiO₂ thin films is analyzed. A red shift in the optical band gap of the films is observed upon dye sensitization. The direct and indirect band gap of the sensitized films is in the range of 3.2-3.8eV and 2.0-2.9 eV respectively.

Index Terms—Band gap, clitoria ternatea, dye sensitization, TiO₂

R. Oommen and P. U. Rajalakshmi are with the Department of Physics, Avinashilingam Institute for Home Science and Higer Eductaion for Women, Coimbatore-43, Tamilnadu, India.
S. Sudha is with the Department of Physics, Varuvan Vadivelan Institute of Technology, Krishnagiri, Tamilnadu, India

Cite: Rachel Oommen, P. Usha Rajalakshmi, and S. Sudha, "Optical Characteristics of TiO₂ Thin Films Sensitized with the Natural Dye of Clitoria Ternatea," International Journal of Applied Physics and Mathematics  vol. 2, no. 6, pp. 439-441, 2012.