Properties of chemical vapour deposited nanocrystalline TiO2 thin films and their use in dye-sensitized solar cells

Nanocrystalline titanium dioxide (TiO2) thin films have been prepared using titanium(IV) isopropoxide as a precursor onto the glass and fluorine doped tin oxide coated glass substrates by chemical vapour deposition technique at 400 °C substrate temperature. X-ray diffraction study confirms the polycrystalline nature of TiO2 with anatase phase having tetragonal crystal structure. The films are 975 nm thick and transparent having transmittance grater than 80%. Atomic force microscopy (AFM) images reveal the nanocrystalline morphology with grain size of ∼200 nm. The film shows a sharp absorption edge near 350 nm. Photoelectrochemical study shows that TiO2 thin film sensitized with Brown Orange dye is found to exhibit relatively maximum Isc and Voc among the studied dyes. The values of fill factor (FF) and efficiency (η) for the dye-sensitized solar cell (Brown Orange dye-sensitized TiO2) are 0.54 and 0.17%, respectively. Such films would serve as better prospects for dye-sensitized solar cells.