Abstract
Three new heteroleptic dithiocarbamate complexes with formula [M(Phen-dione)(Fcdtc)]PF
6
(where M = Ni(
ii
) Ni-Fc, Cu(
ii
) Cu-Fc) and [Co(Phen-dione)(Fcdtc)
2
]PF
6
(Co-Fc) (Fcdtc =
N
-ethanol-
N
-methylferrocene dithiocarbamate and Phen-dione = 1,10-phenanthroline-5,6-dione; PF
6
−
= hexafluorophosphate) were synthesized and characterized using microanalysis, FTIR, electronic absorption spectroscopy and mass spectrometry. The solution state electronic absorption spectroscopy for all three complexes displayed a band at ∼430 nm corresponding to the ferrocene unit and another low-intensity band in the visible region arising because of the d–d transitions. These newly synthesized complexes were used as co-sensitizers for the state-of-the-art di-tetrabutylammonium
cis
-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(
ii
) (N719) dye in dye-sensitized solar cells (DSSCs). Among the three co-sensitizers/co-adsorbent-based DSSC set-ups, the assembly fabricated using Co-Fc/N719 displayed good photovoltaic performance with 5.31% efficiency (
η
) while a new triple component strategy inculcating N719, Co-Fc and Cu-Fc dyes offered the best photovoltaic performance with 6.05% efficiency (
η
) with incident photon to current conversion efficiency (IPCE) of 63%. This indicated an upliftment of the DSSC performance by ∼38% in comparison to the set-up constructed by employing only N719 dye (
η
= 4.39%) under similar experimental conditions.
Three new ferrocene appended heteroleptic dithiocarbamate complexes have been synthesized and used as sensitizers/co-sensitizers in DSSCs.