Efficient flexible dye-sensitized solar cells from rear illumination based on different morphologies of titanium dioxide photoanode

The TiO₂ with nanoparticles (NPs), nanowires (NWs), nanorods (NRs) and nanotubes (NTs) structures were prepared by using a in-situ hydrothermal technique, and then proposed as a photoanode for flexible dye-sensitized solar cell (FDSSC). The influences of the morphology of TiO₂ on the photovoltaic performances of FDSSCs were investigated. Under rear illumination of 100 mW·cm⁻², the power conversion efficiencies of FDSSCs achieved 6.96%, 7.36%, 7.65%, and 7.83% with the TiO₂ photoanodes of NPs, NWs, NRs, and NTs and PEDOT counter electrode. The FDSSCs based on TiO₂ NRs and NTs photoanodes have higher short circuit current densities and power conversion efficiencies than that of the others. The enhanced power conversion efficiency is responsible for their nanotubes and rod-shaped ordered structures, which are more beneficial to transmission of electron and hole in semiconductor compared to the TiO₂ nanoparticles and nanowires disordered structure.