Enediyne as π linker in D–π–A dyes for dye-sensitized solar cells

Abstract

Three Donor–π–Acceptor (D–π–A) type dyes, with triphenylamine (TPA) as electronic donor, enediyne (EDY) moiety as π linker and cyanoacrylic acid as both electronic acceptor and anchoring group, were designed and synthesized. These EDY-bridged dyes with different donor position and number are used as sensitizers in dye-sensitized solar cells (DSSCs) to study the influence of these factors on their performance. The results show that varying the donor position and number shifts the absorbance peak or enhances the absorption intensity, but does not broaden the absorption range. With two donors at both meta- and para-positions, the conjugation length in EDY-3 is broadened, meanwhile, the twisty donors with asymmetric structure endow EDY-3 retarded dye aggregation and charge recombination. Therefore, EDY-3 shows the best performance in DSSCs among the three kinds of dyes with iodide/triiodide solution as electrolyte (J_SC = 12.28 mA cm⁻², V_OC = 730 mV, FF = 60.43% and PCE = 5.41%).