Enhanced Room-Temperature Photoluminescence Quantum Yield in Morphology Controlled J-Aggregates
Abstract
Supramolecular assemblies from organic dyes forming J-aggregates are known to exhibit narrowband photoluminescence with full-width at half maximum of approximate to 9 nm (260 cm(-1)). Applications of these high color purity emitters, however, are hampered by the rather low photoluminescence quantum yields reported for cyanine J-aggregates, even when formed in solution. Here, it is demonstrated that cyanine J-aggregates can reach an order of magnitude higher photoluminescence quantum yield (increase from 5% to 60%) in blend solutions of water and alkylamines at room temperature. By means of time-resolved photoluminescence studies, an increase in the exciton lifetime as a result of the suppression of non-radiative processes is shown. Small-angle neutron scattering studies suggest a necessary condition for the formation of such highly emissive J-aggregates: the presence of a sharp water/amine interface for J-aggregate assembly and the coexistence of nanoscale-sized water and amine domains to restrict the J-aggregate size and solubilize monomers, respectively. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000464000Publication status
publishedExternal links
Journal / series
Advanced ScienceVolume
Pages / Article No.
Publisher
WileySubject
exciton lifetime; J‐aggregates; Microemulsions; photoluminescence quantum yield; radiative excitonsOrganisational unit
03934 - Kovalenko, Maksym / Kovalenko, Maksym
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