The effect of dye-sensitized solar cell based on the composite layer by anodic TiO2 nanotubes

TiO₂ nanotube arrays are very attractive for dye-sensitized solar cells (DSSCs) owing to their superior charge percolation and slower charge recombination. Highly ordered, vertically aligned TiO₂ nanotube arrays have been fabricated by a three-step anodization process. Although the use of a one-dimensional structure provides an enhanced photoelectrical performance, the smaller surface area reduces the adsorption of dye on the TiO₂ surface. To overcome this problem, we investigated the effect of DSSCs constructed with a multilayer photoelectrode made of TiO₂ nanoparticles and TiO₂ nanotube arrays. We fabricated the novel multilayer photoelectrode via a layer-by-layer assembly process and thoroughly investigated the effect of various structures on the sample efficiency. The DSSC with a four-layer photoelectrode exhibited a maximum conversion efficiency of 7.22% because of effective electron transport and enhanced adsorption of dye on the TiO₂ surface.