Direct Imaging of Exciton Transport in Tubular Porphyrin Aggregates by Ultrafast Microscopy.
Long-range exciton transport is a key challenge in achieving efficient solar energy harvesting in both organic solar cells and photosynthetic systems. Self-assembled molecular aggregates provide the potential for attaining long-range exciton transport through strong intermolecular coupling. However,...
| Publicado en: | Journal of the American Chemical Society Vol. 139; no. 21; pp. 7287 - 7294 |
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| Autores principales: | , , , |
| Formato: | Resumen |
| Publicado: |
American Chemical Society
5/31/2017
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=123350481&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 123350481 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 5/31/2017 vid: 139 iid: 21 pid: 997 pub: American Chemical Society artinfo: ui: 123350481 10.1021/jacs.7b01550 ppf: 7287 ppct: 7 formats: tig: atl: Direct Imaging of Exciton Transport in Tubular Porphyrin Aggregates by Ultrafast Microscopy. aug: au: Wan, Yan Stradomska, Anna Knoester, Jasper Huang, Libai affil: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States School of Chemistry, University of Glasgow, University Avenue, Glasgow, G12 8QQ, United Kingdom Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands su: Imaging systems Exciton theory Solar cells sug: subj: Imaging systems Exciton theory Solar cells ab: Long-range exciton transport is a key challenge in achieving efficient solar energy harvesting in both organic solar cells and photosynthetic systems. Self-assembled molecular aggregates provide the potential for attaining long-range exciton transport through strong intermolecular coupling. However, there currently lacks an experimental tool to directly characterize exciton transport in space and in time to elucidate mechanisms. Here we report a direct visualization of exciton diffusion in tubular molecular aggregates by transient absorption microscopy with ∼200 fs time resolution and ∼50 nm spatial precision. These direct measurements provide exciton diffusion constants of 3-6 cm s for the tubular molecular aggregates, which are 3-5 times higher than a theoretical lower bound obtained by assuming incoherent hopping. These results suggest that coherent effects play a role, despite the fact that exciton states near the band bottom crucial for transport are only weakly delocalized (over <10 molecules). The methods presented here establish a direct approach for unraveling the mechanisms and main parameters underlying exciton transport in large molecular assemblies. pubtype: Academic Journal doctype: Abstract src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2017 holdings: @attributes: islocal: N |
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