Fabrication of Dye Sensitized Solar Cell Using Nanocrystalline TiO2 and Optical Characterization of Photo-Anode

Anatase phase containing nano-crystallite TiO2 thin film is prepared by the peptization of modified Ti-isopropoxide sol using HNO3 as peptizing agent. The resulting sol is concentrated in a rotary evaporator bath. TiO2 film is deposited on ITO substrate by spin coating process. The compact film is annealed at 450˚C and 500˚C for optical studies. The subsequently it is modified as photo-anodes in dye sensitized solar cells. The prepared materials are characterized by X-ray diffraction (XRD), UV-Vis absorption spectroscopy and high resolution transmission electron microscopy (HRTEM). The colloidal particles are 6-8nm in average size while the grain growth of the particles are in the order of 13-20nm after annealing of the thin film. The obtained lattice constants of the TiO2 nanocrystals are a=3.79A and c=9.48A from XRD data as compared to JCPDS data of a=3.79A and c=9.52A. The photo conversion efficiency of assembled dye sensitized solar cells comprising of ~5µm thickness of the film are determined to be of the order of 6.77%.