Redox couple related influences of pi-conjugation extension in organic dye-sensitized mesoscopic solar cells

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 pi-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.