Abstract
Thermally activated delayed fluorescence (TADF) is one of the most promising technologies for harvesting triplet excitons in all-organic emitters, a property that is essential for achieving high efficiency in devices. Compounds that operate via this mechanism for emission typically rely on a combination of electron donating and accepting moieties separated by an aromatic bridge. Here we demonstrate that although naphthalene is underutilised as an acceptor, it can nonetheless be used in a donor–acceptor TADF emitter when coupled to two phenoxazines in the 1- and 4-positions. The compound 1,4-PXZ-Nap-PXZ emits at 508 nm, has a photoluminescence quantum yield of 48% and a delayed lifetime of 22.7 ms in a 20 wt% doped film in 1,3-bis(N-carbazolyl)benzene (mCP). An organic light-emitting diode (OLED) using this emitter showed a maximum external quantum efficiency (EQEmax) of 11% and green emission at λEL of 505 nm, demonstrating for the first time the potential of naphthalene-acceptor based emitters for devices. Finally, we have demonstrated by way of a density functional theory (DFT) study why naphthalene alone amongst linear acenes is suitable for this role.
Original language | English |
---|---|
Pages (from-to) | 4273-4286 |
Number of pages | 14 |
Journal | Journal of Materials Chemistry C |
Volume | 12 |
Issue number | 12 |
Early online date | 18 Jan 2024 |
DOIs | |
Publication status | Published - 28 Mar 2024 |
Fingerprint
Dive into the research topics of 'Evaluation of acenes as potential acceptors in thermally activated delayed fluorescence emitters and the promise of a phenoxazine–naphthalene emitter for OLEDs'. Together they form a unique fingerprint.Datasets
-
Evaluation of acenes as potential acceptors in thermally activated delayed fluorescence emitters and the promise of a phenoxazinenaphthalene emitter for OLEDs (dataset)
Lee, O. S. (Creator), Sharma, N. (Creator), Matulaitis, T. (Creator), Slawin, A. M. Z. (Creator), Olivier, Y. (Creator), Samuel, I. D. W. (Creator), Gather, M. C. (Creator) & Zysman-Colman, E. (Creator), University of St Andrews, 5 Feb 2024
DOI: 10.17630/10e31a40-6c9d-4cc4-bffb-02d57683c6f2
Dataset
File -
CCDC 2303516 - 2303518: Experimental Crystal Structure Determination
Lee, O. S. (Creator), Sharma, N. (Creator), Matulaitis, T. (Creator), Slawin, A. M. Z. (Creator), Olivier, Y. (Creator), Samuel, I. D. W. (Creator), Gather, M. C. (Creator) & Zysman-Colman, E. (Creator), Cambridge Crystallographic Data Centre, 2024
DOI: 10.5517/ccdc.csd.cc2h9zzs, https://dx.doi.org/10.5517/ccdc.csd.cc2hb00w and one more link, https://dx.doi.org/10.5517/ccdc.csd.cc2hb01x (show fewer)
Dataset