Coplanar indenofluorene-based organic dyes for dye-sensitized solar cells

A series of new organic dyes, comprising indenofluorene moiety as a conjugated bridge, with an extended π-groups, such as thiophene and furan, diphenylamine as donor, cyanoacrylic acid group as an electron acceptor and anchoring group, have been synthesized. Photophysical and electrochemical measurements, and theoretical computation were carried out on these dyes. Dye-sensitized solar cells (DSSCs) using these dyes as the sensitizers exhibited photocurrent density (JSC), open-circuit voltage (VOC), and fill factor (FF) in the range of 6.95-8.20 mA/cm2, 0.70-0.71 V, and 0.69-0.71, respectively, corresponding to an overall conversion efficiency of 3.36-4.05%. The best efficiency reached 56% of the standard cell based on N719.