Exciton efficiency beyond the spin statistical limit in organic light emitting diodes based on anthracene derivatives
| Autor: | Eduard Spuling, Eli Zysman-Colman, Yoann Olivier, Malte C. Gather, Ifor D. W. Samuel, Alberto Privitera, Graeme Copley, Caroline Murawski, David Hall, Alexandra M. Z. Slawin, Nidhi Sharma, David Beljonne, David B. Cordes, Francisco Tenopala-Carmona, Michael Y. Wong |
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| Přispěvatelé: | The Leverhulme Trust, EPSRC, European Commission, University of St Andrews. School of Chemistry, University of St Andrews. Organic Semiconductor Centre, University of St Andrews. EaSTCHEM, University of St Andrews. School of Physics and Astronomy, University of St Andrews. Sir James Mackenzie Institute for Early Diagnosis, University of St Andrews. Centre for Biophotonics, University of St Andrews. Biomedical Sciences Research Complex, University of St Andrews. Condensed Matter Physics |
| Rok vydání: | 2020 |
| Předmět: |
Anthracene
Materials science Carbazole Exciton DAS 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology QD Chemistry 7. Clean energy 01 natural sciences Fluorescence Molecular physics Acceptor 0104 chemical sciences chemistry.chemical_compound chemistry Excited state Materials Chemistry OLED QD 0210 nano-technology Spin (physics) |
| Zdroj: | Journal of Materials Chemistry C Sharma, N, Wong, M Y, Hall, D, Spuling, E, Tenopala-Carmona, F, Privitera, A, Copley, G, Cordes, D B, Slawin, A M Z, Murawski, C, Gather, M C, Beljonne, D, Olivier, Y, Samuel, I D W & Zysman-Colman, E 2020, ' Exciton efficiency beyond the spin statistical limit in organic light emitting diodes based on anthracene derivatives ', Journal of Materials Chemistry C, vol. 8, no. 11, pp. 3773-3783 . https://doi.org/10.1039/c9tc06356k |
| ISSN: | 2050-7534 |
| DOI: | 10.1039/c9tc06356k |
| Popis: | E.Z.-C. acknowledges the University of St Andrews and the Leverhulme Trust (RPG- 2016-047) for financial support. E.Z.-C. and I.D.W.S. thank EPSRC (EP/P010482/1) for support. We thank EPSRC UK National Mass Spectrometry Facility at Swansea University for analytical services. The work in Mons was supported by the European Union’s Horizon 2020 research and innovation program under Grant Agreement N°. 646176 (EXTMOS project). Computational resources have been provided by the Consortium des Équipements de Calcul Intensif (CÉCI), funded by the Fonds de la Recherche Scientifiques de Belgique (F.R.S.- FNRS) under Grant No. 2.5020.11. C.M. and G.C acknowledge funding by the European Commission through a Marie Skłodowska Curie fellowship (No. 703387 and 799302, respectively). M.C.G. acknowledges funding from EPSRC (EP/R010595/1). A.P. acknowledges the European Union’s Horizon 2020 research and innovation programme under Marie Sklodowska Curie Grant agreement No. 722651 (SEPOMO project). EPR measurements were performed in the Centre for Advanced ESR (CAESR), located in the Department of Chemistry of the University of Oxford, and this work was supported by the EPSRC (EP/L011972/1). We report two donor-acceptor (D-A) materials based on a cyanoanthracene acceptor paired with diphenylamine ( DPAAnCN ) and carbazole ( CzAnCN ) donor moieties. These compounds show hybrid locally excited (LE) charge-transfer (CT) excited states (HLCT), which we demonstrated through a combined photophysical and computational study. Vacuum- deposited organic light emitting diodes (OLEDs) using these HLCT emitters exhibit maximum external quantum efficiencies (EQEmax) close to 6%, with impressive exciton utilization efficiency (Φs) of >50%, far exceeding the spin statistic limit of 25%. We rule out triplet-triplet annihilation and thermally activated delayed fluorescence as triplet harvesting mechanisms along with horizontal orientation of emitters to enhance light outcoupling and, instead, propose a “hot exciton” channel involving the nearly isoenergetic T2 and S1 states. Postprint |
| Databáze: | OpenAIRE |
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