Synthesis and characterization of new electron acceptor perylene diimide molecules for photovoltaic applications

Two new perylene diimide molecules, 1, 7-bis(1-naphtyl)-N,N0-bis-(10-nonadecyl)-perylene-3,4,9,10-bis (dicarboximide) PDI-2 and 1,7-bis(5-acenaphtenyl)-N,N0-bis-(10-nonadecyl)-perylene-3,4,9,10-bis(dicarboximide) PDI-3 have been synthesized and used as acceptor components in P3HT/PDI bulk heterojunction solar cells. The introduction of fused aromatic rings into the bay positions of the perylene core creates a stong steric hindrance, twisting the perylene plane with a direct consequence on the pep intramolecular interactions between the adjacent PDIs. All these features contribute to the reduction of molecular aggregation in the solid state, with a strong influence on the performances of P3HT/PDI photovoltaic devices.