Benzodithiophene Based Organic Dyes for DSSC: Effect of Alkyl Chain Substitution on Dye Efficiency

A series of push-pull triarylamine organic dyes containing the benzo[1,2-b:4,5-b']dithiophene unit as a spacer and bearing alkyl chains in different positions of the molecule were synthesized. The new dyes 1-4 were characterized by optical and electrochemical measurements and density functional theory calculations and tested as sensitizers in liquid dye-sensitized solar cells (DSSC).