The iodide/triiodide redox shuttle is an unparalleled option in making efficient dye-sensitized solar cells (DSCs) but also presents some prominent constraints on the development of new photosensitizers, semiconductors and counter electrodes. In this paper, a cobalt electrolyte has been identified to offer an advantageous impact of π-conjugation extension in push–pull organic dyes, upon the interfacial charge recombination kinetics and thus the open-circuit photovoltage of DSCs, in sharp contrast with the conventional iodine congener. The usage of a solely visible-light-absorption dye has generated a DSC free of corrosive iodine, exhibiting an impressive overall power conversion efficiency of 8.0% at the 100 mW cm−2 AM1.5G conditions.

The iodide/triiodide redox shuttle is an unparalleled option in making efficient dye-sensitized solar cells (DSCs) but also presents some prominent constraints on the development of new photosensitizers, semiconductors and counter electrodes. In this paper, a cobalt electrolyte has been identified to offer an advantageous impact of π-conjugation extension in push–pull organic dyes, upon the interfacial charge recombination kinetics and thus the open-circuit photovoltage of DSCs, in sharp contrast with the conventional iodine congener. The usage of a solely visible-light-absorption dye has generated a DSC free of corrosive iodine, exhibiting an impressive overall power conversion efficiency of 8.0% at the 100 mW cm−2 AM1.5G conditions.