Enhanced performance of dye-sensitized solar cells with fluorine doped nanocrystalline TiO2 as photoanode

In order to enhance the performance of dye-sensitized solar cells (DSSCs), the fluorine doped TiO2 nanoparticles were employed as photonode. Using TiF4 as starting material, fluorine atom is introduced into nanocrystalline TiO2 by a simple method. The TiO2 nanoparticles with uniform F doping were prepared by hydrothermal method, and were further exploited as the application in DSSCs via doctor-blading technique successfully. In addition, the highest conversion efficiency of 6.30% was achieved under one sun illumination (AM 1.5G, 100 mW/cm2), which is about 13% higher than that of the devices using commercial P25 TiO2 nanoparticles, the probably reason could mainly ascribed to the improvement in fill factor and open-circuit voltage. Moreover, the mechanism study demonstrated that the improved cell performance could attributed to the higher amount of dye adsorption on TiO2, the enhanced interfacial charge transfer rate between interconnected TiO2, higher injection rate from dye to TiO2 nanoparticles which was induced by the formation of Ti3+ and F− ions in the semiconductor, and the reduced recombination at the interfacial face between TiO2 and electrolyte.