A red to blue series of push-pull dyes for NiO based p-DSSCs

Abstract

Finding efficient dyes for NiO photocathodes either for inverse or tandem DSSCs is essential to developing these promising low-cost solar cells. This paper reports the design, synthesis and physical property characterization of four new triphenylamine-bithiophene push-pull dyes with acceptors of increasing electronic affinity, in order to shift their absorption to the red region of the visible spectrum. The dyes were tested in a p-type DSSC configuration with 850 nm NiO ink-jet printed photocathodes and their performances were compared with that of the reference dye P1. With an iodine electrolyte, one of the dyes, possessing a 1,3-diethyl-2-thiobarbituric acceptor, shows superior performance to P1, with PCE reaching 0.124% and a J SC of 4.32 mA cm -2 .