Fluorous molecules for dye-sensitized solar cells: synthesis and properties of di-branched, di-anchoring organic sensitizers containing fluorene subunits

Four organic sensitizers having a di-branched molecular structure D–(π–A)2 (D = para-substituted arylamine, π = 9,9-dibutylfluorene, A = cyanoacrylic acid) were synthesized, characterized, and applied in the development of dye-sensitized solar cells (DSSCs). It was found that the nature of the para-substituent affects the behavior of these sensitizers. In particular, the introduction of a C11 linear fluorous alkoxy group led to an improvement in the power conversion efficiency with respect to the commonly employed nonfluorous alkoxy substituents.