Study of Eosin Y sensitized ZnO Solar cell

摘要

Dye sensitized solar cells (DSSC) are based on the photo injection of electrons from dye molecules into an inorganic wide band gap semiconductor and holes transport by a redox mediator. In this study, dye-modified ZnO electrodes were used. ZnO films were prepared on a conductive glass substrate (ITO) using nanosize ZnO powder. The thicknesses of the films were in the range of 6 to 16 μm. The sintered films were found to be polycrystalline in nature. The SEM micrographs of ZnO films exhibited porous structure. The incident monochromatic photon to current conversion efficiency (IPCE) of a solar cell was found to be of the order of 50-55 % at the wavelength of 520 nm. The conversion efficiency of the DSSC was found to be 0.7 % for a 1cm~2 cell. It was found that the conversion efficiency increased with thickness, indicating an increased amount of absorbed dye. In contrast, increasing the ZnO film thickness has decreased the fill factor.