Synthesis and characterization of a new series of dibenzofulvene based organic dyes for DSSCs

Three new 2DepeA dyes (TK4, TK5 and TK6), composed of diarylamine donor groups, a dibenzofulvenethiophene core as the p-bridge, and a cyanoacrylic acid anchoring group as the acceptor, have been successfully designed, synthesized, and characterized both experimentally and computationally. The performance in DSSC solar cells has been also studied. Octyloxy chains were introduced on the backbone of the dye, in order to increase donor capability, avoid aggregation side effects and increase physical insulation between electrolyte system and the TiO2 layer. The dye containing the octyloxy chains on the donor group and two thiophene ring as an extension of p-bridge showed the best photovoltaic performance with a maximum of solar energy-to-electricity conversion yield of 7.8% under AM 1.5 irradiation (100 mW/cm2).