A multifunctional photoanode made of titania submicrospheres and titania nanoparticles modified titania nanotube arrays on FTO glass for dye-sensitized solar cells

We have proposed a novel engineered multifunctional photoanode which consists of one-dimensional (1D) TiO2 nanotube arrays modified by TiO2 nanoparticles as a bottom layer and three-dimensional (3D) TiO2 submicrospheres as a top layer by a simple one-time chemical bath deposition method. This 1D-3D bilayer photoanode simultaneously possesses the incompatible features such as high specific surface area, pronounced light-scattering ability, and fast electron transport. The novel 1D-3D bilayer photoanode demonstrates a power conversion efficiency (PCE) of 6.93%, leading to a 26.5% increment of PCE compared with that of TiO2 bare nanotube arrays (5.48%).