Ruthenium complexes bearing N-heterocyclic carbene based CNC and CN^CHC’ pincer ligands: Photophysics, electrochemistry, and solar energy conversion

Jain, Nimisha; Mary, Angelina; Manjunath, Vishesh; Sakla, Rahul; Devan, Rupesh S.; Jose, D. Amilan; Naziruddin, Abbas Raja

doi:10.1016/j.jorganchem.2021.122203

Cited by 6 publications

(2 citation statements)

References 78 publications

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“…Our previous findings 10 also proved that the –COOH anchors position plays an important role in the electron injection process, so we decided to design new molecules with the anchors in the para position according to the Ru-centers. In the B3 molecule, the π-conjugated ethynyl ligand, present in molecules B1 and B2, is replaced with the phenyl group to stabilize the photogenerated charge and decrease recombination processes 12 – 14 . The main goal of this study is to provide further insight into the mechanism of charge transfer processes occurring in the dinuclear Ru complexes upon photoexcitation.…”

Section: Introductionmentioning

confidence: 99%

The importance of anchoring ligands of binuclear sensitizers on electron transfer processes and photovoltaic action in dye-sensitized solar cells

Bartkowiak,

Korolevych,

Gierczyk

et al. 2023

Sci Rep

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The relatively low photon-to-current conversion efficiency of dye-sensitized solar cells is their major drawback limiting widespread application. Light harvesting, followed by a series of electron transfer processes, is the critical step in photocurrent generation. An in-depth understanding and fine optimization of those processes are crucial to enhance cell performance. In this work, we synthesize two new bi-ruthenium sensitizers with extended anchoring ligands to gain insight into underlying processes determining photovoltaic action mechanisms. The structure of the compounds has been confirmed, and their properties have been thoroughly examined by various techniques such as NMR, IR, elemental analysis UV–Vis, cyclic voltammetry, and electroabsorption. The experimental characterization has been supported and developed via extensive quantum-chemical calculations, giving a broad view of the presented molecules’ properties. Finally, the DSSC devices have been assembled utilizing obtained dyes. The photovoltaic and EIS measurements, combined with performed calculations and fundamental dyes characterization, unraveled an intramolecular electron transfer as an initial step of the electron injection process at the dye/semiconductor interface. The overall photovoltaic action mechanism has been discussed. Our study demonstrates the significance of the anchoring group architecture in the molecular design of new sensitizers for DSSC applications.

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Section: Introductionmentioning

confidence: 99%

The importance of anchoring ligands of binuclear sensitizers on electron transfer processes and photovoltaic action in dye-sensitized solar cells

Bartkowiak,

Korolevych,

Gierczyk

et al. 2023

Sci Rep

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“…These chelating NHCs could coordinate to the ruthenium center through wider bite angles [6a] . Near octahedral bite angle at the metal centers achieved through chelate ligands render stronger ligand fields that would destabilize the otherwise easily accessible metal‐centered states [6e,7] . However, the nature of the ligand spacer strongly influences their photophysical attributes [6e,8] …”

Section: Introductionmentioning

confidence: 99%

Ruthenium Complexes Bearing Bis‐N‐heterocyclic Carbene Donors in TiO₂ Sensitization for Dye‐Sensitized Solar Cells

et al. 2022

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This report presents ruthenium (II) complexes featuring bisimidazole-2-ylidene donors and carboxylic acid-functionalized terpyridine ligands (tpyÀ COOH or tpy 4'À phenyl À COOH). We introduced the monodentate À NCS or pyridine carboxylate ligands into the coordination sphere to render sizeable changes in photo-functional attributes. The coordination of the thiocyanate ligands to these ruthenium centers extends their absorption tails up to 800 nm. In contrast, the absorption bands of complexes featuring isonicotinic acid last only until 600 nm.Even though phenyl spacers at the acceptor end rendered a bathochromic shift in the λ max , in their absence, complexes exhibited a longer electron lifetime at the TiO 2 photoanode. The complexes devoid of phenyl spacers show lower charge transfer resistance at the TiO 2 /electrolyte interface giving improved photon conversion efficiency (PCE) in Dye-Sensitized Solar Cells (DSSCs). Herein, we analyze the relationship between the structure and the light-harvesting efficiency via a combined experimental and computational approach.

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Ruthenium (II) complexes bearing N‐heterocyclic carbene‐based C^N donor sets in dye‐sensitized solar cells

Mary

Jain

Sakla

et al. 2022

Applied Organom Chemis

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We present the syntheses of ruthenium (II) complexes bearing an N-heterocyclic carbene (NHC)-based C^N donor set and an NCS ligand and evaluate their use as photosensitizers in dye-sensitized solar cells (DSSCs). These complexes deploy a monocarboxylic acid-functionalized terpyridine (tpy)/phenyl-tpy to anchor with the TiO 2 of the photoanodes. Results show that the complexes devoid of the phenyl spacer between the acid anchor and the tpy harvest the visible light more effectively. Absorption of the visible light transfers the electron density from the ruthenium, NHC, and the NCS donors to the tpy acceptor ( 1 M Ru L donor L acceptor CT). Stronger M Ru L donor σ-bonds in the complexes with opposite NHC and tpy ligand configuration render facile ruthenium-centered oxidation. In contrast, the metal-centered oxidation of complexes with trans-oriented NHC and NCS ligands is relatively difficult. However, these complexes display higher photon conversion efficiency (PCE) in DSSCs. One of them shows PCE of 3.44%, which is $70% of the standard N3 dye, under similar conditions. A longer electron lifetime and the lowest charge transfer resistance at the TiO 2 /electrolyte interface derived from the electrochemical impedance spectra accounts for the enhanced PCE. Insights into the oxidized dye regeneration in a DSSC setup, obtained from the computed Hirshfeld charges and spin density, depict the essential role of iodide anion in dye regeneration. This report summarizes our investigation of photophysics, electronic structure calculations, and the electrochemical study of all newly prepared complexes and their use as photosensitizers in DSSCs.

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Ruthenium complexes bearing N-heterocyclic carbene based CNC and CN^CHC’ pincer ligands: Photophysics, electrochemistry, and solar energy conversion

Cited by 6 publications

References 78 publications

The importance of anchoring ligands of binuclear sensitizers on electron transfer processes and photovoltaic action in dye-sensitized solar cells

The importance of anchoring ligands of binuclear sensitizers on electron transfer processes and photovoltaic action in dye-sensitized solar cells

Ruthenium Complexes Bearing Bis‐N‐heterocyclic Carbene Donors in TiO₂ Sensitization for Dye‐Sensitized Solar Cells

Ruthenium (II) complexes bearing N‐heterocyclic carbene‐based C^N donor sets in dye‐sensitized solar cells

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Ruthenium complexes bearing N-heterocyclic carbene based CNC and CN^CHC’ pincer ligands: Photophysics, electrochemistry, and solar energy conversion

Cited by 6 publications

References 78 publications

The importance of anchoring ligands of binuclear sensitizers on electron transfer processes and photovoltaic action in dye-sensitized solar cells

The importance of anchoring ligands of binuclear sensitizers on electron transfer processes and photovoltaic action in dye-sensitized solar cells

Ruthenium Complexes Bearing Bis‐N‐heterocyclic Carbene Donors in TiO2 Sensitization for Dye‐Sensitized Solar Cells

Ruthenium (II) complexes bearing N‐heterocyclic carbene‐based C^N donor sets in dye‐sensitized solar cells

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Ruthenium Complexes Bearing Bis‐N‐heterocyclic Carbene Donors in TiO₂ Sensitization for Dye‐Sensitized Solar Cells