Figure 2From: A maskless synthesis of TiO2-nanofiber-based hierarchical structures for solid-state dye-sensitized solar cells with improved performanceFESEM images of the secondary growth on TiO 2 nanofibers at different reaction time. (a) 10 min, (b) 30 min, (c) 45 min, (d) 1 h, (e) 2 h, and (f) 3 h. Insets show the magnified images of nanostructures.Back to article page