High-efficiency dye-sensitized solar cells based on ultra-long single crystalline titanium dioxide nanowires

• 3D networks of single crystalline TiO2 nanowire membranes were grown on Ti foils.
• Self-standing TiO2 nanowire membranes were used to fabricate front-side photoanodes.
• The highest power conversion efficiency of DSCs could attain to 8.05%.

High-efficiency dye-sensitized solar cells (DSCs) based on 3D networks of ultra-long single crystalline TiO2 nanowires are fabricated. By hydrothermal reaction of Ti foils in alkali aqueous solution, following ion exchange and high temperature sintering processes, the ultra-long single crystalline TiO2 nanowires can be prepared. Due to long enough of the TiO2 nanowires, they not only form 1D arrays perpendicular to Ti foils, but also extend to form 3D network structure on the top-side of the arrays. By optimizing the hydrothermal duration at 24 h, the formed TiO2 nanowire membrane based front-side illuminated photoanode shows enhanced dye-loading and light scattering abilities and excellent charge transport properties. So the DSC with this photoanode can attain to the highest power conversion efficiency about 8.05%.