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Reducing efficiency roll-off in multi-resonant thermally activated delayed fluorescent OLEDs through modulation of the energy of the T2 state
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dc.contributor.author | Wang, Tao | |
dc.contributor.author | Gupta, Abhishek Kumar | |
dc.contributor.author | Cordes, David B. | |
dc.contributor.author | Slawin, Alexandra M. Z. | |
dc.contributor.author | Zysman-Colman, Eli | |
dc.date.accessioned | 2023-03-20T11:30:03Z | |
dc.date.available | 2023-03-20T11:30:03Z | |
dc.date.issued | 2023-05-19 | |
dc.identifier | 283397030 | |
dc.identifier | 48f7810d-a6e5-47bd-ad9d-fd285ce2ddad | |
dc.identifier | 85150276235 | |
dc.identifier.citation | Wang , T , Gupta , A K , Cordes , D B , Slawin , A M Z & Zysman-Colman , E 2023 , ' Reducing efficiency roll-off in multi-resonant thermally activated delayed fluorescent OLEDs through modulation of the energy of the T 2 state ' , Advanced Optical Materials , vol. 11 , no. 10 , 2300114 . https://doi.org/10.1002/adom.202300114 | en |
dc.identifier.issn | 2195-1071 | |
dc.identifier.other | ORCID: /0000-0002-9527-6418/work/131588430 | |
dc.identifier.other | ORCID: /0000-0002-5366-9168/work/131588517 | |
dc.identifier.other | ORCID: /0000-0001-7183-6022/work/131588846 | |
dc.identifier.uri | https://hdl.handle.net/10023/27220 | |
dc.description | Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska Curie grant agreement No. 897098 (AIE-RTP-PLED). T.W. acknowledges support from the Marie Skłodowska-Curie Individual Fellowship. The auhors thank the EPSRC (EP/R035164/1) for financial support. | en |
dc.description.abstract | The S1 state and high-lying triplet excited states (ΔES1Tn) offer insight into clarifying the mechanism of efficiency roll-off of organic light-emitting diodes (OLEDs). However, experimental detection of the ΔES1Tn is challenging due to Kasha's rule. Here, two emitters, PhCz-O-DiKTa and PhCz-DiKTa , showing multi-resonant thermally activated delayed fluorescence (MR-TADF) are reported. By modulating the conjugation between the MR-TADF DiKTa emissive center and donor substituent, emission directly from the T2 state is for the first time observed in MR-TADF emitters. Single crystal and reduced density gradient analyses reveal the origin of the reduced observed concentration-quenching results from weak CH···π and slipped π···π stacking interactions, which suppress nonradiative transitions. Theoretical and photophysical investigations reveal that the ΔES1T2 difference influences the reverse intersystem crossing rate. The OLEDs employing PhCz-O-DiKTa and PhCz-DiKTa as emitters show maximum external quantum efficiencies (EQEmax) of over 20%, but very different efficiency roll-off behavior (54.5% vs 13.6% at 100 cd m−2). Thus, this design provides a possible solution to mitigating device efficiency roll-off by designing MR-TADF emitters with degenerate S1 and T2 states. | |
dc.format.extent | 10 | |
dc.format.extent | 6410145 | |
dc.language.iso | eng | |
dc.relation.ispartof | Advanced Optical Materials | en |
dc.subject | Multi-resonant thermally activated delayed fluorescence (MR-TADF) | en |
dc.subject | Emissive T2 state | en |
dc.subject | Narrowband emission | en |
dc.subject | Conjugation modulation | en |
dc.subject | Organic light emitting diodes | en |
dc.subject | QD Chemistry | en |
dc.subject | DAS | en |
dc.subject | MCC | en |
dc.subject.lcc | QD | en |
dc.title | Reducing efficiency roll-off in multi-resonant thermally activated delayed fluorescent OLEDs through modulation of the energy of the T2 state | en |
dc.type | Journal article | en |
dc.contributor.sponsor | European Commission | en |
dc.contributor.sponsor | EPSRC | en |
dc.contributor.institution | University of St Andrews. School of Chemistry | en |
dc.contributor.institution | University of St Andrews. Institute of Behavioural and Neural Sciences | en |
dc.contributor.institution | University of St Andrews. EaSTCHEM | en |
dc.contributor.institution | University of St Andrews. Centre for Energy Ethics | en |
dc.identifier.doi | 10.1002/adom.202300114 | |
dc.description.status | Peer reviewed | en |
dc.identifier.grantnumber | 879098 | en |
dc.identifier.grantnumber | EP/R035164/1 | en |
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