Metal‐Free Sensitizers with a Perfluorohexyl Side Chain for Dye‐Sensitized Solar Cells: Properties Alien to Alkyl Chains

Abstract

New fluorene dyes containing ap erfluorohexyl or an n-hexyl side chain in the conjugated spacer (thiophene) were synthesized for application in dye-sensitized solar cells. The perfluoro dyes more effectively suppress the charger ecombination than their congeners containing ah exyl chain, which leads to ah ighero pen-circuit voltage (V OC ). The more efficient dark currents uppression afforded by the perfluorohexyl-containing dyes was also confirmed by electrochemical impedance spectroscopy.Aperfluoro-containing dye exhibited the bestp owerc onversion efficiencyo ft he synthesized compounds, whichw as furtheri mproved to 6.73 %b yt he addition of chenodeoxycholic acid (10 mm)a sac o-adsorbant. The hydrophobic perfluorohexyl-containing dyes are more resistantt ol eachingd ue to the presence of moisture, leadingtoh ighertemporal stabilityo ft he DSSCs.