Photovoltaic performance of nanostructured zinc oxide sensitised with xanthene dyes

The photovoltaic properties of nanostructured ZnO electrodes prepared from commercially available ZnO nanoparticles (Degussa) and sensitised with xanthene dyes are explored. We have used Eosin Y, Eosin B and Mercurochrome and compared their performance to that of the more common N719 dye. We observe that these dyes efficiently sensitise commercial ZnO nanopowder and yield efficiencies that are very competitive with respect to those provided by N719. Local photocurrent and transmittance measurements as a function of the wavelength confirm the good performance of the xanthene dyes in the absorption maxima. We have prepared polymer-sealed cells and measured the short-circuit current of the devices under continuous illumination at 200 mW/cm2 corresponding to twice the standard solar light intensity. The organic dyes show very good stability properties under these conditions. The combination of a versatile metal oxide such as ZnO and inexpensive organic dyes should be considered as a promising alternative in the field of dye-sensitised solar cells.