Photovoltaic performance and physical characterization of Cu doped ZnO nanopowders as photoanode for DSSC

In this study, the effects of two fabrication factors, the Cu doping and the dye adsorption time on the ZnO-DSSC, were systematically investigated. ZnO nanostructures were obtained by hydrothermal synthesis method at different Cu doping ratio (0%, 0.1%, 1%, 3%) and used as photoanode in DSSC. The effects of Cu incorporation to ZnO on the morphological, structural, and optical properties were examined. As a result of XRD analysis, it was determined that all samples have highly crystallized hexagonal wurtzite structure. The doping process has caused the formation of protruding surfaces in the ZnO nanostructure and increased the surface area, which has been observed using SEM images. X-ray photoelectron spectroscopy (XPS) study demonstrated Cu-O and Zn-O bonding in the synthesized flake-shaped Cu doped ZnO nanostructures, which confirmed the Zn substitution by the Cu-ions. The maximum cell efficiency of 2.03% was achieved in DSSC when photoanode was fabricated by using %0.1 Cu doped ZnO nanopowder dipped in N719 solution for only one hour. The efficiency of DSSC with Cu doped ZnO photoanode has improved by 20%, and the dye adsorption time has been decreased by three times, obviously.