Display options
Cite
Nowak-Król A, Fimmel B, Son M, et al. Photoinduced electron transfer (PET) versus excimer formation in supramolecular p/n-heterojunctions of perylene bisimide dyes and implications for organic photovoltaics. Faraday Discuss. 2015;185:507-27doi: 10.1039/c5fd00052a.
Nowak-Król, A., Fimmel, B., Son, M., Kim, D., & Würthner, F. (2015). Photoinduced electron transfer (PET) versus excimer formation in supramolecular p/n-heterojunctions of perylene bisimide dyes and implications for organic photovoltaics. Faraday discussions, 185507-27. https://doi.org/10.1039/c5fd00052a
Nowak-Król, Agnieszka, et al. "Photoinduced electron transfer (PET) versus excimer formation in supramolecular p/n-heterojunctions of perylene bisimide dyes and implications for organic photovoltaics." Faraday discussions vol. 185 (2015): 507-27. doi: https://doi.org/10.1039/c5fd00052a
Nowak-Król A, Fimmel B, Son M, Kim D, Würthner F. Photoinduced electron transfer (PET) versus excimer formation in supramolecular p/n-heterojunctions of perylene bisimide dyes and implications for organic photovoltaics. Faraday Discuss. 2015;185:507-27. doi: 10.1039/c5fd00052a. PMID: 26399996.
Copy Download .nbib Format: NLM
Share it on

Faraday Discuss. 2015;185:507-27. doi: 10.1039/c5fd00052a.

Photoinduced electron transfer (PET) versus excimer formation in supramolecular p/n-heterojunctions of perylene bisimide dyes and implications for organic photovoltaics.

Faraday discussions

Agnieszka Nowak-Król, Benjamin Fimmel, Minjung Son, Dongho Kim, Frank Würthner

Affiliations

  1. Universität Würzburg, Institut für Organische Chemie & Center for Nanosystems Chemistry, Am Hubland, 97074 Würzburg, Germany. [email protected].
  2. Spectroscopy Laboratory for Functional ?-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea. [email protected].

PMID: 26399996 DOI: 10.1039/c5fd00052a

Abstract

Foldamer systems comprised of two perylene bisimide (PBI) dyes attached to the conjugated backbones of 1,2-bis(phenylethynyl)benzene and phenylethynyl-bis(phenylene)indane, respectively, were synthesized and investigated with regard to their solvent-dependent properties. UV/Vis absorption and steady-state fluorescence spectra show that both foldamers exist predominantly in a folded H-aggregated state consisting of π-π-stacked PBIs in THF and in more random conformations with weaker excitonic coupling between the PBIs in chloroform. Time-resolved fluorescence spectroscopy and transient absorption spectroscopy reveal entirely different relaxation pathways for the photoexcited molecules in the given solvents, i.e. photoinduced electron transfer leading to charge separated states for the open conformations (in chloroform) and relaxation into excimer states with red-shifted emission for the stacked conformations (in THF). Supported by redox data from cyclic voltammetry and Rehm-Weller analysis we could relate the processes occurring in these solution-phase model systems to the elementary processes in organic solar cells. Accordingly, only if relaxation pathways such as excimer formation are strictly avoided in molecular semiconductor materials, excitons may diffuse over larger distances to the heterojunction interface and produce photocurrent via the formation of electron/hole pairs by photoinduced electron transfer.

Publication Types