The application of freestanding TiO2 nanotubes on the photovoltaic performance of dyesensitized solar cells utilizing front side illumination has been investigated. TiO2 nanotubes were grown on Ti foil using the anodization process at a constant voltage of 60 V for various anodization times such as 2, 4, and 6 h. Subsequently, the formations of freestanding films of close-ended and open-ended TiO2 nanotubes were carried out via a second anodization step at 40 and 80 V, respectively. X-ray diffraction analysis revealed the formation of amorphous structure TiO 2 nanotubes before annealing and anatase phase after annealing at 450°C. The diameter (60-90-nm-inner diameter) and thickness (7-19 lm) of TiO2 nanotubes were measured from scanning electron microscopy and transmission electron microscopy analysis. The detached TiO2 nanotube films were affixed on FTO substrates employing anatase TiO2 paste. The fixation of freestanding TiO2 nanotubes on FTO substrates can be categorized as three parts namely: close-ended nanotubes downside, close-ended nanotubes upside, and open-ended nanotubes. Among the various anodization times, the cells fabricated using 6 h anodized TiO2 nanotubes photoelectrode attained excellent photoelectric efficiencies of 6.91, 6.47, and 7.69% for close-ended downside, close-ended upside and open ended, respectively. The DSSCs based on open-ended photoelectrodes achieved the highest photoelectrical conversion efficiency are due to higher dye loading amount.
- Dye-sensitized solar cells
- Energy conversion