Carbene-based ruthenium photosensitizers?

Dalton Transactions Pub Date: 2011-05-19 DOI: 10.1039/C1DT10072F

Abstract

A new series of N-heterocyclic carbene (NHC)-pyridine ruthenium complexes incorporating a carbene unit as an ancillary ligand were designed and successfully synthesized by using simple synthetic methods. The photophysical, electrochemical and photovoltaic properties of these NHC-pyridine based ruthenium complexes were investigated. These complexes showed photoelectric conversion efficiencies in the range of 6.43 ~ 7.24% under the illumination of AM 1.5 (100 mW cm?2). Interestingly, the modifications on the ancillary ligand of these sensitizers by removal of an alkoxyl group and replacement of the octyl chain with a 3,5-difluorobenzyl group showed a 13% increase in the conversion efficiency for the CifPR dye. These results demonstrated that structural modifications on the NHC-pyridine ancillary ligand of ruthenium complexes results in dye-sensitized solar cells exhibiting a comparable cell performance to that obtained using the standard N719 dye.

Graphical abstract: Carbene-based ruthenium photosensitizers
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