Band gap engineering of TiO2 nanostructure-based dye solar cells (DSCs) fabricated via electrophoresis

This work describes a simple method utilizing electrophoretic deposition (EPD) as versatile technique to deposit of commercial TiO2 (P25) nanopartcles (NPs) films on the fluoride-doped tin oxide (FTO) substrate. The main goal of this study is investigating the effects of surface treatment on the properties of nanoporous P25 electrodes in order to efficiently control and optimize the main fabrication step of the dye-sensitized solar cells (DSSCs). In order to increase of the electron transfer efficiency in DSSC, post-treatment of P25 films using TiCl4 has been carried out. As a result, cell efficiencies were improved about 40%. Solar cells based on a core–shell structure, including a ZnO as shell and a P25 as core, have been investigated. Results demonstrated that ZnO/P25 film electrode was enable to enhance of short-circuit photocurrent density (JSC) and consequently solar conversion efficiency for a DSSC by 10%, compared to those of a DSSC containing a bare P25 film electrode. The results were attributed to increase the concentration of free electrons in the conduction band (CB) of P25.