Four new pyrrole-based organic sensitizers with different isolation groups were conveniently synthesized andapplied to dye sensitized solar cells (DSCs). The introduction of isolation group in the side chain could both suppress theformation of dye aggregates and electron recombination. Especially, when two pieces of D-π-A chromophore moieties shared oneisolation group to construct the “H” type dye, the performance was further improved. Consequently, in the corresponding solarcell of LI-57, a short-circuit photocurrent density (Jsc) was tested to be 13.85 mA cm?2, while 0.72 V for the open-circuitphotovoltage (Voc), 0.64 for the fill factor (FF), and 6.43% for the overall conversion efficiency (η), exceeding its analogue LI-55(5.94%) with the same isolation group. The results demonstrated that both the size (bulk and shape) and the linkage modebetween the D-π-A chromophores and the isolation groups, could affect the performance of sensitizers in DSCs in a large degree,
providing a new approach to optimize the chemical structure of dyes to achieve high conversion efficiencies.
