Synthesis and Investigation of the Donor Effect in Novel Hemicyanine Organic Dyes for p-Type Dye-Sensitized Solar Cells

Organic dyes were synthesized with the donor moieties, carbazole, phenothiazine and triphenylamine, and the current voltage characteristics and charge transfer of the p-DSSCs with these dyes were measured. The effect of the donor in an organic dye on the optical and electrochemical properties was investigated and compared with the reference dye, C343. The device with the carbazole donor dye outperformed the dyes with phenothiazine and triphenylamine donor groups and even the reference coumarine dye giving the best solar cell performance with J(SC) = 6.5 A m(-2), V-OC = 0.103 V, FF = 0.30, and an efficiency of 0.02%. Electrochemical impedance analysis was performed to understand the effect of the donor group on the charge transfer properties. The results showed that the carbazole based dye exhibited the best charge transfer ability.