Fabrication and characterization of ZnO:Cu and ZnO:Mn based dye-sensitized solar cells

In this study, nanostructured zinc oxide (ZnO) powders were obtained by hydrothermal synthesis method. The obtained ZnO nanostructures were doped with copper (Cu) and manganese (Mn) elements at dopant rates of 0.1%, 0.5%, 1%, 3% and 8%. The effects of dopants on the morphological, structural, and optical properties on the nanostructure of the doped ZnO were examined by Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD), X-Ray Photoelectron Spectrometer (XPS), and UV-VIS Spectrophotometer. The undoped and doped nanostructured ZnO powders were made into paste and coated on fluorine doped tin oxide (FTO) coated glass surfaces with doctor blade method. The produced films were gradually annealed at 450 °C, then they were immersed in a rutenyum 535-bis TBA dye solution and dye was impregnated on them. In order to examine the effect of dipping time, the films were subjected to the dipping process for different time periods. The time period was limited as the cells reached saturation of efficiency. Dye immersed ZnO films have been characterized by XRD, SEM and UV-VIS spectrophotometer devices. Afterwards, the dye-absorbed films were clipped with a platinum-coated counter electrode to provide a sandwich-type DSSC formation and iodide solution was added as the electrolyte. The current density-voltage (J-V) graphs of the ZnO-based dye sensitized solar cells (DSSC) were obtained under the solar simulator. With these curves; Solar cell efficiency (η), short circuit current density (Jsc), open circuit voltage (Voc), filling factor (FF) values were obtained and cell performances were evaluated.