Zn-Zn porphyrin dimers have been incorporated into thin dye-sensitized solar cells (DSSCs) to boost their light harvesting efficiency. The photoexcited dimers show efficient and fast electron injection into TiO2 indicating that both photoexcited chromophores contribute to current generation. The improved light harvesting ability coupled to enhanced DSSC performance demonstrates the potential of 3-D tight harvesting arrays as next generation light harvesters for artificial solar energy conversion systems.