Photovoltage Improvement for Dye-Sensitized Solar Cells via Cone-Shaped Structural Design

Abstract

In this article, three truexene-based dyes with 2-cyanoacrylic acid as acceptor and starburst triarylamine as donor (S5, S6, and S7) were conveniently synthesized and used for dye-sensitized solar cells (DSSCs). A compact sensitizer layer is molecular interfacially engineered on the TiO 2 surface via cone-shaped sensitizers. As a result, the approach of the electrolyte to the TiO 2 surface is blocked significantly by the compact sensitizer layer formed and the charge recombination in the DSSCs is proved to be retarded effectively. The monochromatic incident photon-to-current conversion efficiency of these sensitizers is near 90%. In addition, S7-sensitized solar cells yield an open-circuit voltage of 752 mV and a fill factor of 0.70, which are even higher than those of N719 under the same conditions.