Highly-ordered arrays of TiO2 thin film for dye-sensitized solar cells fabricated by anodic oxidation process

Abstract

Highly ordered arrays of TiO2 photoelectrode thin films of dye-sensitized solar cells (DSSCs) were fabricated by anodic oxidation method. This study analyzed the effects of electrolytes under similar NH4F concentrations but different reaction times in the anodic oxidation process on the photoelectric conversion efficiency of DSSC, open-circuit voltage decay, electron lifetime, and incident photon-to-electron conversion efficiency (IPCE) of the prepared DSSC. Experimental results show that the TiO2 nanotube thin film prepared by anodic oxidation with an electrolyte with a NH4F concentration at 0.5 wt% and with a reaction time of 5 hr can be fabricated with a length of 17 μm and a photoelectric conversion efficiency of 4.87%, open-circuit voltage of 0.74 V, and short-circuit current density of 13.2 mA/cm2. Additionally, the same NH4F concentration but with a reaction time of 10 hr achieves a length of 22 μm and a photoelectric conversion efficiency of 6.58%, open-circuit voltage of 0.81 V, and short-circuit current density of 16.1 mA/cm2.