Recent Progress in Dye-Sensitized Solar Cells for Improving Efficiency: TiO₂ Nanotube Arrays in Active Layer

Figure 5

Growth of regular TiO₂ nanotube arrays: (a) cathodic reaction, (b) anodic reaction, (c) transition state of TiO₂ layer, (d) beginning of nanotube formation, and (e) TiO₂ nanotube arrays. Reprinted with permission from [43]. Copyright 2012, Elsevier.