Enhanced Room‐Temperature Photoluminescence Quantum Yield in Morphology Controlled J‐Aggregates

Advanced Science

Thilo Stöferle¹  Rainer F. Mahrt¹  Jay Patel²  Surendra B. Anantharaman²  Frank A. Nüesch²  Jakob Heier²  Joachim Kohlbrecher³  Maksym Kovalenko⁴  Sergii Yakunin⁴  Gabriele Rainò⁴ 

[1] IBM Research–Zurich Säumerstrasse 4, Rüschlikon Zürich CH‐8803 Switzerland;Laboratory for Functional Polymers Empa Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129 Dübendorf CH‐8600 Switzerland;Laboratory for Neutron Scattering and Imaging (LNS) Paul Scherrer Institute Villigen CH‐5232 Switzerland;Laboratory of Inorganic Chemistry Department of Chemistry and Applied Biosciences ETH Zürich Vladimir Prelog‐Weg 1 Zürich CH‐8093 Switzerland;

关键词: exciton lifetime;    J‐aggregates;    microemulsions;    photoluminescence quantum yield;    radiative excitons;   

DOI  :  10.1002/advs.201903080

来源: DOAJ

【 摘 要 】

Abstract Supramolecular assemblies from organic dyes forming J‐aggregates are known to exhibit narrowband photoluminescence with full‐width at half maximum of ≈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.

【 授权许可】

Unknown