Growth of TiO2 nanotubes on the Ti foil by anodizing method used in the flexible dye-sensitized solar cell in presence of three counter electrodes

In this work, flexible dye-sensitized solar cells were made by using different counter electrodes. The working electrode was fabricated from a simple anodizing method. TiO2 film was grown on the Ti foil as a flexible substrate. uniUsing Ti foil for the flexible solar cell helped us to sinter the grown TiO2 nanotubes at high temperature that is a serious challenge for the flexible plastic substrates. To study the effect of counter electrodes on the solar cell performance, three different counter electrodes namely platinum (Pt), multi-walled carbon nanotube (MWCNT) and graphene were served. The results showed the Pt was the best counter electrode due to its high catalytic activity and nobility. MWCNT had the better activity than the graphene due to its higher conductivity to electron transfer. The crystallinity of the TiO2-Ti electrode was examined by X-ray diffraction pattern. The TiO2 electrode and counter electrodes surfaces were studied by scanning electron microscopy. Also, the optical properties of the surface were obtained by ultra violet-visible spectroscopy. Finally, The solar cells performance was investigated by J-V curve.