Dijkstra, AG, Duan, HG, Knoester, J et al. (2 more authors) (2016) How two-dimensional brick layer J-aggregates differ from linear ones: Excitonic properties and line broadening mechanisms. Journal of Chemical Physics, 144 (13). 134310. ISSN 0021-9606
Abstract
We study the excitonic coupling and homogeneous spectral line width of brick layer J-aggregate films. We begin by analysing the structural information revealed by the two-exciton states probed in two-dimensional spectra. Our first main result is that the relation between the excitonic couplings and the spectral shift in a two-dimensional structure is different (larger shift for the same nearest neighbour coupling) from that in a one-dimensional structure, which leads to an estimation of dipolar coupling in two-dimensional lattices. We next investigate the mechanisms of homogeneous broadening - population relaxation and pure dephasing - and evaluate their relative importance in linear and two-dimensional aggregates. Our second main result is that pure dephasing dominates the line width in two-dimensional systems up to a crossover temperature, which explains the linear temperature dependence of the homogeneous line width. This is directly related to the decreased density of states at the band edge when compared with linear aggregates, thus reducing the contribution of population relaxation to dephasing. Pump-probe experiments are suggested to directly measure the lifetime of the bright state and can therefore support the proposed model.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016, The Authors. Published by AIP Publishing, This is an author produced version of a paper published in Journal of Chemical Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 08 Sep 2016 14:49 |
Last Modified: | 21 Jan 2018 11:12 |
Published Version: | http://dx.doi.org/10.1063/1.4944980 |
Status: | Published |
Publisher: | AIP Publishing |
Identification Number: | 10.1063/1.4944980 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:104449 |