Charge-transfer dynamics and interligand electron transfer (ILET) phenomena play a pivotal role in dye-sensitizers, mostly represented by the Ru-based polypyridyl complexes, for TiO2 and ZnO-based solar cells. Starting from metal-to-ligand charge-transfer (MLCT) excited states, charge dynamics and ILET can influence the overall device efficiency. In this letter, we focus on N34– dye ( [Ru(dcbpy)2(NCS)2]4–, dcbpy = 4,4′-dicarboxy-2,2′-bipyridine) to provide a first direct observation with high time resolution (<20 fs) of the ultrafast electron exchange between bpy-like ligands. ILET is observed in water solution after photoexcitation in the ∼400 nm MLCT band, and assessment of its ultrafast time-scale is here given through a real-time electronic dynamics simulation on the basis of state-of-the-art electronic structure methods. Indirect effects of water at finite temperature are also disentangled by investigating the system in a symmetric gas-phase structure. As main result, remarkably, the ILET mechanism appears to be based upon a purely electronic evolution among the dense, experimentally accessible, MLCT excited states manifold at ∼400 nm, which rules out nuclear–electronic couplings and proves further the importance of the dense electronic manifold in improving the efficiency of dye sensitizers in solar cell devices.

Nature of the Ultrafast Interligands Electron Transfers in Dye-Sensitized Solar Cells / Perrella, F.; Li, X.; Petrone, A.; Rega, N.. - In: JACS AU. - ISSN 2691-3704. - 3:1(2022), pp. 70-79. [10.1021/jacsau.2c00556]

Nature of the Ultrafast Interligands Electron Transfers in Dye-Sensitized Solar Cells

Perrella F.
Primo
;
Petrone A.
Penultimo
;
Rega N.
Ultimo
2022

Abstract

Charge-transfer dynamics and interligand electron transfer (ILET) phenomena play a pivotal role in dye-sensitizers, mostly represented by the Ru-based polypyridyl complexes, for TiO2 and ZnO-based solar cells. Starting from metal-to-ligand charge-transfer (MLCT) excited states, charge dynamics and ILET can influence the overall device efficiency. In this letter, we focus on N34– dye ( [Ru(dcbpy)2(NCS)2]4–, dcbpy = 4,4′-dicarboxy-2,2′-bipyridine) to provide a first direct observation with high time resolution (<20 fs) of the ultrafast electron exchange between bpy-like ligands. ILET is observed in water solution after photoexcitation in the ∼400 nm MLCT band, and assessment of its ultrafast time-scale is here given through a real-time electronic dynamics simulation on the basis of state-of-the-art electronic structure methods. Indirect effects of water at finite temperature are also disentangled by investigating the system in a symmetric gas-phase structure. As main result, remarkably, the ILET mechanism appears to be based upon a purely electronic evolution among the dense, experimentally accessible, MLCT excited states manifold at ∼400 nm, which rules out nuclear–electronic couplings and proves further the importance of the dense electronic manifold in improving the efficiency of dye sensitizers in solar cell devices.
2022
Nature of the Ultrafast Interligands Electron Transfers in Dye-Sensitized Solar Cells / Perrella, F.; Li, X.; Petrone, A.; Rega, N.. - In: JACS AU. - ISSN 2691-3704. - 3:1(2022), pp. 70-79. [10.1021/jacsau.2c00556]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/908453
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