Enhanced efficiency of tri-layered dye solar cells with hydrothermally synthesized titania nanotubes as light scattering outer layer

► Fabrication of dye sensitized solar cells with a tri-layer photoanode. ► TiO2 nano tubes as light scattering outer layer. ► Compact TiO2 layer for better performance. ► Enhanced power conversion efficiency of 7.15%. ► Electrochemical impedance spectroscopy study of the electron transport properties.