Natural Dye-Sensitized Solar Cells Based on Highly Ordered TiO2 Nanotube Arrays
Figure 1
Top view SEM images of TiO2 nanotube arrays (a) before and (b) after the ultrasonic treatment. The inset in (a) is the image with high magnification, while the inset in (b) shows the cross-sectional view of the nanotube arrays after ultrasonic treatment.
