Effect of TiCl4-based TiO2 compact and blocking layers on efficiency of dye-sensitized solar cells

The effect of the number and arrangement of TiO2-based photoanode layers on the efficiency of dye-sensitized solar cells (DSSCs) was investigated. Compact, mesoporous, and blocking layers of TiO2 were prepared to form monolayer, bilayer, and trilayer photoanodes. Compact and blocking TiO2 layers were prepared using dip-coating technique, whereas the doctor-blade method was employed to prepare TiO2 paste layers using nanoparticles prepared by the sol-gel method. The crystalline structure of photoanodes was characterized by X-ray diffraction (XRD) measurements and their morphology and thickness were characterized by the scanning electron microscopy (SEM) technique. The photovoltaic performance of constructed DSSC devices was investigated and the optimum arrangement was identified and explained in terms of dye loading enhancement and recombination reduction at the fluorine-doped tin oxide (FTO)/electrolyte interface.