Facile preparation of a Nb2O5 blocking layer for dye-sensitized solar cells

The introduction of a niobium oxide layer between fluorine-doped tin oxide (FTO) and TiO2 electrodes is known to enhance the power conversion efficiency (η) of dye-sensitized solar cells (DSSCs). Nb thin films were deposited on FTO glass substrates using RF magnetron sputtering. TiO2 pastes were then screen-printed onto the Nb thin films. The multilayered structures were annealed at 500 °C in a muffle furnace and assembled with Pt counter electrodes for DSSC performance evaluation. The Nb thin films were oxidized during the calcination process, producing a post-oxidized layer that increased the solar-cell efficiency by about 15 % and the photocurrent density by approximately 25 %.