Fabrication of dye sensitized solar cells using BaTiO3 blocking layer

Dye-sensitized solar cells (DSSCs) have great potential for solar generation due to their low cost and simplicity of fabrication compared with silicon-based photovoltaic devices. One of the major problems with TiO2-based DSSCs is the recombination loss at the substrate–electrolyte interface due to the mesoporous nature of the TiO2 film. It was proposed earlier that introduction of a blocking layer at the substrate–TiO2 interface could reduce this recombination loss by preventing direct contact of the substrate and electrolyte. In this present work, Barium titanate (BaTiO3) nanoparticles prepared by using wet chemical method. The prepared nanoparticles were thermally evaporated on to well cleaned fluorine-doped tin oxide (FTO) glass under the vacuum of 2 x10-5 torr at different thickness and used as electron-blocking layer of dye-sensitized solar cell (DSSC). The BaTiO3 blocking layer functions as an energy barrier at the FTO–electrolyte interface to prevent back transfer of electrons to the electrolyte from the FTO. The blocking effect of the BaTiO3 blocking layer was verified by an enhancement of the fill factor (FF) and open-circuit photovoltage (Voc) of the DSSC, leading to an improvement in the power conversion efficiency (PCE) from 3.86% to 4.34% for the BaTiO3 blocking layer with optimum thickness of 80 nm. The TiO2 layers were printed on top BaTiO3 to assemble for a dye sensitized solar cells. DSSCs with the structure of FTO/BaTiO3/TiO2/Dye/EL/Pt/FTO have been prepared, and their solar-cell performance was evaluated..