Iodine-Doped ZnO Nanocrystalline Aggregates for Improved Dye-Sensitized Solar Cells

A hierarchically structured primary photovoltaic (PV) nanomaterial based on iodine-doped ZnO nanocrystalline aggregates (ZnO:I) exhibiting large internal surface area as well as strong light scattering property, which can be used as effective photoanode in dye-sensitized solar cells (DSSCs) was reported. Highly monodispersed and spherically structured ZnO:I nanocrystalline aggregates were synthesized by the solvothermal process from zinc salt and iodic acid in polyol medium along with heating at 160°C. The ZnO:I film of approximately 8 μm in thickness was formed using a drop-cast method onto a fluorine-doped tin oxide (FTO) coated glass substrate and subsequently followed by calcinations at 350°C for 60 min in air. For comparison, undoped ZnO film with thickness of δ8μm identical to that of the ZnO:I film was also prepared, and it was found that the two films maintained analogous structure and morphology. The reported doping system is expandable to other non-metal doped semiconductors that may be used to enhance the DSSC performance.