Effects of ligand LUMO levels, anchoring groups and spacers in Ru(II)-based terpyridine and dipyrazinylpyridine complexes on adsorption and photoconversion efficiency in DSSCs

Sepehrifard, Ali; Chen, Siguang; Stublla, Arta; Potvin, Pierre; Morin, Sylvie

doi:10.1016/j.electacta.2012.09.025

Cited by 17 publications

(8 citation statements)

References 45 publications

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“…Of note, we were surprised by the low peak %IPCE values obtained for cells built from the Steric Series given that the peak %IPCE value for a cell with the homoleptic version of ligand 1 (i.e., [Ru( 1 ) 2 ] 2+ ) was reported at 13.8%, compared to our studies with [Ru( 1 )(tbtpy)] 2+ at 3.2% (see Table ). Because our %IPCE spectrum for the N719 dye is well matched to the literature, we rule out measurement error.…”

Section: Resultscontrasting

confidence: 88%

Exploiting Conformational Dynamics of Structurally Tuned Aryl-Substituted Terpyridyl Ruthenium(II) Complexes to Inhibit Charge Recombination in Dye-Sensitized Solar Cells

Spettel

Damrauer

2016

J. Phys. Chem. C

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To explore the impact of dye structure on photoinduced interfacial electron-transfer (ET) processes, a series of systematically tuned 4′-aryl-substituted terpyridyl ruthenium(II) complexes have been studied in TiO2 film and dye-sensitized solar cell (DSSC) device settings. Structural tuning is achieved by the introduction of methyl substituents at the ortho positions of a ligand aryl moiety. Solar power conversion efficiencies are measured, and these values are deconstructed to better understand the fundamental processes that control light-to-current conversion. Injection yields are identified as the primary factor limiting efficiencies, due in large part to significant nonradiative decay pathways in these bis-terpyridyl Ru(II) systems. Encouragingly, the addition of methyl steric bulk is found to inhibit charge recombination, with measured recombination lifetimes increasing by over 12-fold across the series of structurally tuned complexes. If injection yields can be improved, the structural tuning of recombination rate constants may be an important design strategy for improving solar conversion efficiency in solar cells and water-splitting devices.

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Section: Resultscontrasting

confidence: 88%

Exploiting Conformational Dynamics of Structurally Tuned Aryl-Substituted Terpyridyl Ruthenium(II) Complexes to Inhibit Charge Recombination in Dye-Sensitized Solar Cells

Spettel

Damrauer

2016

J. Phys. Chem. C

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“…This difference in the first oxidation potential is 4-fold larger than that of 6 and 7 and demonstrates a greater effect of functional group additions on the NHC ligand. 23 The first oxidation potentials of the protonated forms of 7 (1.65) 42 and 9 (1.78 V) 23 are similar, suggesting that 2 and 4 (when protonated) are both weaker electron-donating ligands than 1.…”

Section: ■ Results and Discussionmentioning

confidence: 98%

Bis-tridentate N-Heterocyclic Carbene Ru(II) Complexes are Promising New Agents for Photodynamic Therapy

et al. 2020

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Ruthenium(II) complexes developed for photodynamic therapy (PDT) are almost exclusively tris-bidentate systems with C 2 or D 3 symmetry. This is due to the fact that this structural framework commonly produces longlived excited states, which, in turn, allow for the generation of large amounts of singlet oxygen ( 1 O 2 ) and other reactive oxygen species. Complexes containing tridentate ligands would be advantageous for biological applications as they are generally achiral (D 2d or C 2v symmetry), which eliminates the possibility of multiple isomers which could exhibit potentially different interactions with chiral biological entities. However, Ru(II) complexes containing tridentate ligands are rarely studied as candidates for photobiological applications, such as PDT, since they almost exclusively exhibit low quantum yields and very short excited-state lifetimes and, thus, are not capable of generating sufficient 1 O 2 or engaging in electron transfer reactions. Here, we report a proof-of-concept approach to make bis-tridentate Ru(II) complexes useful for PDT applications by altering their photophysical properties through the inclusion of N-heterocyclic carbene (NHC) ligands. Three NHC and two terpyridine ligands were studied to evaluate the effects of structural and photophysical modulations of bis-substituted Ru(II) complexes. The NHC complexes were found to have superior excited-state lifetimes, 1 O 2 production, and photocytotoxicity. To the best of our knowledge, these complexes are the most potent light-activated bis-tridentate complexes reported.

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“…Sepehrifard et al [ 138 , 139 ] investigated a series of homoleptic bis-tridentate ruthenium complexes, employing both tpy and dipyrazinyl-pyridine ligands. The poorer performances of the latter ones were attributed to lower LUMO levels and weaker bonding to TiO 2 .…”

Section: Modifications Of Black Dye and Structure-properties Relatmentioning

confidence: 99%

Terpyridine and Quaterpyridine Complexes as Sensitizers for Photovoltaic Applications

et al. 2016

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Terpyridine and quaterpyridine-based complexes allow wide light harvesting of the solar spectrum. Terpyridines, with respect to bipyridines, allow for achieving metal-complexes with lower band gaps in the metal-to-ligand transition (MLCT), thus providing a better absorption at lower energy wavelengths resulting in an enhancement of the solar light-harvesting ability. Despite the wider absorption of the first tricarboxylate terpyridyl ligand-based complex, Black Dye (BD), dye-sensitized solar cell (DSC) performances are lower if compared with N719 or other optimized bipyridine-based complexes. To further improve BD performances several modifications have been carried out in recent years affecting each component of the complexes: terpyridines have been replaced by quaterpyridines; other metals were used instead of ruthenium, and thiocyanates have been replaced by different pinchers in order to achieve cyclometalated or heteroleptic complexes. The review provides a summary on design strategies, main synthetic routes, optical and photovoltaic properties of terpyridine and quaterpyridine ligands applied to photovoltaic, and focuses on n-type DSCs.

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Effects of ligand LUMO levels, anchoring groups and spacers in Ru(II)-based terpyridine and dipyrazinylpyridine complexes on adsorption and photoconversion efficiency in DSSCs

Cited by 17 publications

References 45 publications

Exploiting Conformational Dynamics of Structurally Tuned Aryl-Substituted Terpyridyl Ruthenium(II) Complexes to Inhibit Charge Recombination in Dye-Sensitized Solar Cells

Exploiting Conformational Dynamics of Structurally Tuned Aryl-Substituted Terpyridyl Ruthenium(II) Complexes to Inhibit Charge Recombination in Dye-Sensitized Solar Cells

Bis-tridentate N-Heterocyclic Carbene Ru(II) Complexes are Promising New Agents for Photodynamic Therapy

Terpyridine and Quaterpyridine Complexes as Sensitizers for Photovoltaic Applications

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