Constructing Synergetic Trilayered TiO₂ Photoanodes Based on a Flexible Nanotube Array/Ti Substrate for Efficient Solar Cells

Abstract A TiO₂ photoelectrode on flexible Ti substrate for dye‐sensitized solar cells was constructed via layer‐by‐layer assembly of one‐dimensional (1D) nanotube arrays (bottom layer), three‐dimensional (3D) microsized leaves (intermediate layer), and zero‐dimensional (0D) TiO₂ nanoparticles (top layer) generated by anodic oxidation, hydrothermal treatment, and screen coating, respectively. The novel 1D‐3D buxus‐liked bilayer presents superior light scattering and favorable charge collection. After integrating 14 μm TiO₂ nanoparticles with a 12 μm buxus‐like double‐layered photoanode, an excellent power conversion efficiency of 8.02 % (short circuit current density J_sc=17.03 mA cm⁻², open circuit voltage V_oc=0.78 V, and fill factor FF=60.4 %) was obtained that outperformed a cell based on titanium nanotube arrays–TiO₂ nanoparticles with a similar film thickness (6.30 %).