Preparation of doping metal TiO₂ particle/nanotube composite layer and their applications in dye-sensitized solar cells

Abstract

Dye-sensitized solar cells (DSSCs) are composed of a dye-adsorbed nanoporous TiO₂ layer on a fluorinedoped tin oxide (FTO) glass substrate, redox electrolytes, and a counter electrode. DSSCs are constructed through the application of nano-metals and TiO₂ nanoparticle/TiO₂ nanotube (TNT) composite particles with various compositions. The use of oxide semiconductors in the form of nanorods, nanowires, and nanotubes is an interesting approach to improve electron transport through the film. In addition, a suitable amount of TNT in the film could provide a large surface area for the adsorption of the dye. A nano-metal is proposed, wherein the conduction band (CB) prohibits the trapping effects of electrons within the TiO₂ conduction band. This result is attributed to the prevention of electron recombination between the electrons in the TiO₂ conduction band with dye or electrolytes. A TiO₂ composite layer was coated onto FTO glass using a screen-printing method. The dye-sensitized solar cells were fabricated using N719 ruthenium (II) dye and I₃/I₃ ⁻ electrolyte. The impedance results indicate improved electron transport at the TiO₂/dye/electrolyte interface. The DSSC based on the Fe₂O₃/TiO₂/TNT composite particle hybrids exhibits better photovoltaic performance than the cell made from only TiO₂ nanoparticles.