Influence of TiO2 coating thickness on energy conversion efficiency of dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) were synthesized using a 0.25 cm2 area TiO2 nanoparticle/nanorod layer as an electrode and platinum (Pt) as a counter electrode. The TiO2 nanoparticle/nanorod layer was prepared by spin coating and spray coating on fluorine-doped tin oxide glass, respectively. The Pt counter electrode and the ruthenium dye anchored electrode were then assembled as a function of thickness of the TiO2 nanorod layer in a range of 8 to 30 µm. The best photovoltaic performance was observed in the case of a DSSC consisting of a 600 nm thick TiO2 nanoparticle layer and a 20 µm thick TiO2 nanorod layer: a short circuit current density of 11.54 mA·cm−2, open circuit voltage of 0.72V, fill factor of 61.2%, and energy conversion efficiency of 5.07%. A TiO2 nanorod/nanoparticle electrode layer with good adhesion was successfully fabricated.