Spray deposited Nb2O5 thin film electrodes for fabrication of dye sensitized solar cells

Nb2O5 thin film electrodes have been deposited on indium tin oxide substrates by spray pyrolysis technique. XRD analysis reveals tetragonal phase of the film. Reticulated micro-fibrous surface morphology has been observed by scanning electron microscopy and atomic force microscopy indicates closely packed crystallites. Film thickness found using a stylus profilometer is around 26 nm. Transmittance spectra show the film to be 70-80% transparent in the visible region. Direct, indirect band gap and phonon energy are also estimated. Cyclic voltammetry measurement indicate distinct anodic peak during negative potential of the scan due to Li extraction. A reversible colour change from transparent to grey has been observed. The photo-electrochemical characteristic of the dye sensitized solar cell is studied by recording the I-V characteristics of the unsealed type cell under illumination of 40 mW/cm(2) using a solar simulator.