Tandem dye-sensitized solar cell for improved power conversion efficiencies

The power conversion efficiency of dye-sensitized solar cells crucially depends on the ability of the sensitizer to absorb light in a broad range of the solar spectrum. In order to increase this range of absorption, a tandem structure with two different sensitizer dyes in two different compartments of the cell, respectively, was realized. Overall power conversion efficiencies as high as eta=10.5% and short circuit current densities of J(SC)=21.1 mA/cm(2) were achieved under air mass 1.5 illumination with red dye and black dye in the upper and lower compartment of the cell, respectively. (C) 2004 American Institute of Physics.