Abstract
TiO2 nanotube arrays prepared by electrochemical anodization of Ti foils show impressive light to electricity conversion efficiency in the dye-sensitized solar cells (DSCs). The length of the TiO2 nanotube arrays (5-14 mu m) was controlled by varying the anodization time from 2 to 20 h. The influence of nanotube lengths on the photovoltaic performance of DSCs was investigated by impedance. A flexible DSC using TiO2 nanotube arrays on a Ti foil as a working electrode and polyethylene naphthalate (ITO/PEN) as counterelectrode in combination with solvent-free ionic liquid electrolyte achieved 3.6% photovoltaic conversion efficiency under simulated AM 1.5 sunlight.