C60-small arylamine push-pull dyads for single-material organic solar cells

The synthesis of two dyads involving small arylamine-based push-pull systems as donor block and C60 fullerene as acceptor connected by a flexible insulating linker formed by esterification is described. After analysis of their electronic properties by cyclic voltammetry and UV–Vis absorption spectroscopy, the potential of these molecules as active material for single-material organic solar cells has been evaluated in simple devices of direct structure. Both dyads lead to modest conversion efficiencies of ∼0.40% due essentially to poor fill factors. These results are discussed in terms of insufficient nano-phase separation of the donor and acceptor blocks and of fall of hole-mobility of the donor block consecutive to the linking to C60.