Influence of various titanium oxide blocking layers on performance of dye-sensitized solar cells

Abstract

Recently emerging efficiency records of Dye-Sensitized Solar Cells (DSSCs) are achieved by blocking photoelectrons recombination at interface of transparent conductive oxide (TCO) / electrolyte. This mechanism shunts the solar cell and occurs in liquid electrolyte-based DSCs and even more in solid-state DSCs such as Perovskite Solar Cells (PSCs). Typical approach that minimizes the issue is use of Blocking Layers (BL) at the interface. In this study, various titanium oxide BLs were successfully deposited via Pulsed Laser Deposition (PLD) on TCO substrates of liquid-based DSSCs and their effect on the performance of DSSCs was investigated. It was found that the fill factor (FF) was increased from 0.59 up to 0.64, the open circuit voltage (Voc) was partially increased from 671 millivolts to 677 millivolts and finally, the efficiency was enhanced from 5.32 percent to 5.41 percent in spite of reduced optical transmittance. Observed improvement of certain properties of the cells, such as FF, implies that these materials obtained by PLD can serve as a new type of BL in DSCs, possibly for PSCs.