Diketopyrrolopyrrole-based sensitizers for dye-sensitized solar cell applications: anchor engineering

Abstract

A series of donor–chromophore–anchor (D–C–A) sensitizers comprising the diketopyrrolopyrrole (DPP) chromophore were synthesized and tested in both I₃⁻/I⁻ and Co[(bpy)]^3+/2+ redox shuttle DSC devices. The dye series was strategically designed to elucidate structure–property relationships, concerning overall performance and compatibility with these two electrolytes. Selective fluorine incorporation improved I₃⁻/I⁻-based DSC performance, while hindering performance with the positively charged cobalt-based redox shuttle. Incorporation of a pyridine heterocycle into the DPP chromophore increased spectral breadth, but decreased performance metrics for both electrolyte systems. These results are understood through detailed electrochemical, photophysical, and computational studies.