2-(2,3,4,5,6-Pentafluorophenyl)-1H-benzo[d]imidazole, a fluorine-rich building block for the preparation of conjugated polymer donors for organic solar cell applications

We have introduced the pentafluorophenyl substituted benzimidazole as a building block of conjugated polymers for optoelectronic applications. We present the synthesis of a copolymer bearing fluorene as the comonomer. A detailed characterization of the novel material including structural, electrochemical and optical (using absorption, emission and time-resolved photoluminescence techniques) properties as well as computational modeling is described. The polymer exhibits highly efficient photoluminescence quenching when blended with fullerene derivatives (PCBM). The experimental results are compared with the alternating fluorene copolymer (APFO-3) in order to identify structure and property relations with the novel synthesized conjugated polymer. Early photovoltaic performance data are presented and compared with the well established APFO-3 : PCBM material system.