A New Series of Heteroleptic Cd(II) Diimine-Ferrocenyl Dithiocarbamate Complexes which Successfully Co-Sensitizes TiO2 Photoanode with Ru N719 Dye in DSSC

Abstract

New heteroleptic complexes of the form [Cd(diimine)(Fcdtc)2] (diimine= 1,10-phenanthroline (phen), Fcdtc=N-ferrocenyl-N-pyridin-3-ylmethyl dithiocarbamate (KL1) Cd1; 2,2’-bipyridyl (bpy), N-ferrocenyl-N-pyridin-4-ylmethyl dithiocarbamate (KL2) Cd2; bpy, (KL1) Cd3 and phen, (KL2) Cd4) have been synthesised and characterized by elemental analyses, spectroscopy (IR, UV-Vis., 1H and 13C {1H} NMR) and their structures have been revealed by X-ray crystallography. These complexes have been explored as co-sensitizers with N719 over TiO2 for application as dye sensitized solar cells (DSSC) photoanodes. The use of these complexes as co-sensitizers resulted in extended UV-Visible spectral response, greater dye loading, enhanced electron life time, reduced charge recombination and thermodynamically more facile charge transfer in the DSSC. Among all the co-sensitized cells (Cd1/N719, Cd2/N719, Cd3/N719 and Cd4/N719), the Cd1-based cell demonstrated not only the highest incident photon to current efficiency (IPCE) 47% but the obtained current conversion efficiency 3.84%, was much higher than that of the N719 based cell (2.70%) under the same illumination condition. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim