Kinetics of the photoexcited states in thin films of metallo-supramolecular polymers with ditopic thiophene-bridged terpyridine ligands

0552548 - ÚMCH 2023 RIV CH eng J - Journal Article
Menšík, Miroslav - Rais, David - Thottappali, Muhammed Arshad - Güloglu, Pinar - Toman, Petr - Vohlídal, J. - Pfleger, Jiří
Kinetics of the photoexcited states in thin films of metallo-supramolecular polymers with ditopic thiophene-bridged terpyridine ligands.
Frontiers in Chemistry. Roč. 9, 20 January (2022), č. článku 766121. ISSN 2296-2646. E-ISSN 2296-2646
R&D Projects: GA MŠMT(CZ) LTAUSA19066
Institutional support: RVO:61389013
Keywords : metallo-supramolecular polymers * transient absorption spectroscopy * singlet and triplet excitons
OECD category: Polymer science
Impact factor: 5.5, year: 2022
Method of publishing: Open access
https://www.frontiersin.org/articles/10.3389/fchem.2021.766121/full

Managing the excited-state decay by a supramolecular structure is a crucial issue for organic photovoltaics. We show that in thin films of metallo-supramolecular polymers made of bis(terpyridine-4′-yl)terthiophenes and Zn2+ coupling ions, the photoexcited states generated by ultrashort laser pulses at the wavelength of 440 nm decay by the bi-molecular annihilation predominantly controlled by the Förster transfer between singlet states. During this bi-molecular annihilation of singlet states, intermediate hot triplet pairs are formed, which subsequently dissociate into long-living diffusing triplet states. It explains a significant shortening of the triplet state rise time with increasing pump fluence. The diffusion coefficient of triplets showed power-law time dependence, with its exponent proportional to the pump fluence, decreasing thus the diffusivity of triplets.
Permanent Link: http://hdl.handle.net/11104/0328632