In-situ synthesis of TiO2 network nanoporous structure on Ti wire substrate and its application in fiber dye sensitized solar cells

In this paper, we explore a two-step treatment method to modify the Ti wires which are used as anode substrates of fiber dye sensitized solar cells (FDSSCs). A special kind of network nanoporous structure is formed on the surface of Ti wire substrates through sodium hydroxide hydrothermal reaction and titanium tetrachloride (TiCl 4 ) assistant treatment. Nanoporous structures with different sizes are in-situ grown on the Ti wire substrates by changing the hydrothermal reaction condition. Then, TiO 2 network nanoporous structures with branch-like nano-structure or 2D nanoflakes are obtained after TiCl 4 treatment. The effects of these network nanoporous structures on the FDSSC performances are investigated intensively. It is found that these special network nanoporous structures between TiO 2 nanoparticle active layer and Ti wire substrate are beneficial to the connection of the nanoparticle layer and fiber-shaped substrate, thus improving the electron transport rate and prolonging electron lifetime . As a result, the power conversion efficiency of this parallel assembled FDSSC increases to 4.64% from 2.56% after this two-step treatment.