Fabrication and characterization of Eosin-Y-sensitized ZnO solar cell

Dye-sensitized solar cells using ZnO nanoparticles and an organic dye, Eosin-Y, were fabricated under various conditions, such as sintering temperature, the thickness of a ZnO electrode and the distance between electrodes. The effects of fabrication conditions on, the photovoltaic characteristics of dye-sensitized ZnO solar cells were investigated. The short-circuit current and conversion efficiency were increased by increasing the thickness of sintered ZnO films, but the fill factor decreased due to the increased series resistance. The best performance achieved in the present work was a conversion efficiency of 2.4% for a 1 cm(2) cell. In order to obtain a model of dye-sensitized solar cells, current-voltage characteristics under the dark condition were analyzed using a thermionic emission model. The estimated barrier height and the ideal factor of the ZnO/electrolyte interface were 0.54 eV and 2.1, respectively. A current-dependent effective barrier height was established by illumination of dye-sensitized ZnO solar cells.