Lévy defects in matrix-immobilized J aggregates : tracing intra-and intersegmental exciton relaxation
Abstract
One-dimensional J aggregates present narrow and intense absorption and emission spectra that are interesting for photonics applications. Matrix immobilization of the aggregates, as required for most device architectures, has recently been shown to induce a non-Gaussian (Lévy type) defect distribution with heavy tails, expected to influence exciton relaxation. Here we perform two-dimensional electronic spectroscopy (2DES) in one-dimensional J aggregates of the cyanine dye TDBC, immobilized in a gel matrix, and we quantitatively model 2DES maps by nonlinear optimization coupled to quantum mechanical calculations of the transient excitonic response. We find that immobilization causes strong non-Gaussian off-diagonal disorder, leading to a segmentation of the chains. Intersegmental exciton transfer is found to proceed on the picosecond time scale, causing a long-lasting excitation memory. These findings can be used to inform the design of optoelectronic devices based on J aggregates as they allow for control of exciton properties by disorder management.
Citation
Lüer , L , Rajendran , S K , Stoll , T , Ganzer , L , Rehault , J , Coles , D M , Lidzey , D , Virgili , T & Cerullo , G 2017 , ' Lévy defects in matrix-immobilized J aggregates : tracing intra-and intersegmental exciton relaxation ' , Journal of Physical Chemistry Letters , vol. 8 , no. 3 , pp. 547-552 . https://doi.org/10.1021/acs.jpclett.6b02704
Publication
Journal of Physical Chemistry Letters
Status
Peer reviewed
ISSN
1948-7185Type
Journal article
Description
L.L. thanks the EC for financial support by the cofunded Amarout program and the Spanish Ministry for economy and competitiveness (plan nacional, Project MultiCrom (CTQ2014-58801)). G.C. acknowledges financial support by the European Research Council (ERC-2011-AdG No. 291198). D.G.L. and D.C. thank the UK EPSRC for funding via research grant EP/M025330/1 “Hybrid Polaritonics”Collections
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