Synthesis of Density-controllable TiO2 Nanowire Bundle Arrays and Their Application in Quantum Dot Sensitized Solar Cell

Highly oriented single-crystalline rutile TiO2 nanowire bundle arrays on transparent conductive fluorine- doped tin oxide (FTO) substrates were synthesized by hydrothermal method using the precursors of tetrabutyl titan- ate, deionized water and hydrochloric acid. The density of the TiO2 nanowire bundle can be tuned by changing the concentration of tetrabutyl titanate. Using the nanowire bundle array as the photoanode, CdS as sensitizer, the quantum dot sensitized solar cell (QDSSC) was assembled. The effects of nanowires density on photovoltaic per- formance of solar cell were investigated. It is found that the cell presents poor photovoltaic performance if the nanowires density is too high or too low. The optimal nanowires density for highest photovoltaic performance is 11.8×10 6 /mm 2 when the photoelectric conversion efficiency reaches 0.947%.