Room Temperature Synthesis of Highly Compact TiO₂ Coatings by Vacuum Kinetic Spraying to Serve as a Blocking Layer in Polymer Electrolyte-Based Dye-Sensitized Solar Cells

Vacuum kinetic spraying (VKS) was used to form a blocking layer (BL) in order to increase the efficiency of dye-sensitized solar cells. Nano-sized TiO₂ powders were deposited on fluorine-doped tin oxide (FTO) glass while varying the coating parameters including the mass flow, substrate transverse speed, and number of coating passes in order to control the thickness of the BL. Compared to the cell without a BL, the open-circuit voltage and short-circuit current density of the solar cell with a VKS-coated BL were noticeably improved. Consequently, the photoconversion efficiency increased up to 5.6%, which is significantly higher than that of a spin-coated BL.