Core-functionalized dendritic oligothiophenes—novel donor–acceptor systems

Abstract

Novel core-functionalized dendritic oligothiophenes (DOT) bearing pyridine or methylpyridinium acceptors have been synthesized up to the third generation. A bathochromic shift in the absorption of the functionalized dendritic oligothiophenes and the appearance of new absorption bands were noticed issuing from an intramolecular charge transfer process. These novel donor–acceptor systems are, due to their broad absorption, promising materials for optoelectronic applications such as organic solar cells. By electrochemical measurements HOMO/LUMO energy levels have been determined and two compounds could be identified with almost ideal energy levels for application in bulk heterojunction solar cells (BHJSC) with fullerene PC₆₁BM as acceptor.