Synthesis of novel multi-chromophoric soluble perylene derivatives and their photosensitizing properties with wide spectral response for SnO₂ nanoporous electrode

Two series of new multi-chromophoric perylene-3,4:9,10-tetracarboxylic dianhydride dyes for solar cell sensitizers have been synthesized. One series consists of oxadiazole or naphthaldicarboximide that are linked with perylene units as N,N'-substituted chromophores. The other series has four substituents in the bay-region of the perylene core in addition to N,N'-substituents. These novel routes to highly efficient sensitizers for Gratzel-type solar cells avoid the complication of doping. A wide spectral photoresponse (from 310 to 700 nm) was observed with maximum IPCE (incident photon-to-current efficiency) of 24%. In addition, the sensitization is dependent on the energy match of the energy bands of the semiconductor and the redox potential of the segments in such assembled dyes.