Abstract
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.
Original language | English |
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Pages (from-to) | 3773-3783 |
Number of pages | 11 |
Journal | Journal of Materials Chemistry C |
Volume | 8 |
Issue number | 11 |
DOIs | |
Publication status | Published - 21 Mar 2020 |
Equipment
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High Performance Computing Technology Platform
Benoît Champagne (Manager)
Technological Platform High Performance ComputingFacility/equipment: Technological Platform
Datasets
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CCDC 1960941: Experimental Crystal Structure Determination
Sharma, N. (Creator), Wong, M. Y. (Creator), Hall, D. (Creator), Spuling, E. (Creator), Tenopala-Carmona, F. (Creator), Privitera, A. (Creator), Copley, G. (Creator), Cordes, D. B. (Creator), Slawin, A. M. Z. (Creator), Murawski, C. (Creator), Gather, M. C. (Creator), Beljonne, D. (Creator), Olivier, Y. (Contributor), Samuel, I. D. W. (Creator) & Zysman-Colman, E. (Creator), University of Namur, 21 Mar 2020
DOI: 10.5517/ccdc.csd.cc23tj5n, http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc23tj5n&sid=DataCite
Dataset
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CCDC 1960942: Experimental Crystal Structure Determination
Sharma, N. (Creator), Wong, M. Y. (Creator), Hall, D. (Creator), Spuling, E. (Creator), Tenopala-Carmona, F. (Creator), Privitera, A. (Creator), Copley, G. (Creator), Cordes, D. B. (Creator), Slawin, A. M. Z. (Creator), Murawski, C. (Creator), Gather, M. C. (Creator), Beljonne, D. (Creator), Olivier, Y. (Contributor), Samuel, I. D. W. (Creator) & Zysman-Colman, E. (Creator), University of Namur, 21 Mar 2020
DOI: 10.5517/ccdc.csd.cc23tj6p, http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc23tj6p&sid=DataCite
Dataset