Tuning Chiroptical Properties and Device Hyperfluorescence Efficiency via Acceptor Modification in an Intramolecularly Sensitised TADF Dendrimer
5 affiliations
- 1Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews St Andrews KY16 9ST UK
- 2Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University Suzhou Jiangsu 21523 P. R. China
- 3University of Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 F-35000 Rennes France
- 4Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
- 5Institute of Biological and Chemical Systems (IBCS-FMS), Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
Abstract
Multi-resonant thermally activated delayed fluorescence (MR-TADF) emitters offer an attractive solution for the fabrication of colour-saturated organic light-emitting diodes (OLEDs). Still, their rigid frameworks often lead to slow reverse intersystem crossing and aggregation-caused quenching. To address these challenges and simultaneously introduce chiroptical properties in solution-processable materials, here we present the first examples of chiral intramolecular Förster resonance energy transfer (FRET) MR-TADF dendrimers, CzPBN-CzBN and CzPBA-CzBN. These emitters combine an MR-TADF core with chiral paracyclophane (CzP)-based donor dendrons linked to different acceptor units, benzonitrile for CzPBN-CzBN and benzoic acid for CzPBA-CzBN. While both dendrimers show narrowband TADF emission, the nature of the acceptor impacts their chiroptical properties. Specifically, CzPBA-CzBN exhibits circularly polarised luminescence (CPL), whereas CzPBN-CzBN does not due to a weaker circular dichroism signal. Conversely, in solution-processed hyperfluorescent (HF) OLEDs, the device with CzPBN-CzBN achieved a superior maximum external quantum efficiency (EQEmax) of 19.7% and lower efficiency roll-off (EQE of 18.9% at 1000 cd m‑2) compared to the device with CzPBA-CzBN (EQEmax/1000 = 17.2/16.5%). These findings reveal an intrinsic trade-off between CPL response and HF device performance, demonstrating how precise modulation of the excited-state manifold via acceptor engineering can be used to tailor the properties of intramolecular sensitised TADF emitters.
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BibTeX
@article{fatahi2026tuning,
title = {{Tuning Chiroptical Properties and Device Hyperfluorescence Efficiency via Acceptor Modification in an Intramolecularly Sensitised TADF Dendrimer}},
author = {Mahni Fatahi and Yan Xu and Dongyang Chen and Praveen Choudhary and Jhon Sebastian Oviedo Ortiz and Jasmin Seibert and Stefan Bräse and Jeanne Crassous and Xiao-Hong Zhang and Eli Zysman-Colman},
journal = {Chemical Science},
year = {2026},
month = sep,
doi = {10.1039/d6sc04906k},
url = {https://hal.science/hal-05742046v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Tuning Chiroptical Properties and Device Hyperfluorescence Efficiency via Acceptor Modification in an Intramolecularly Sensitised TADF Dendrimer
AU - Mahni Fatahi
AU - Yan Xu
AU - Dongyang Chen
AU - Praveen Choudhary
AU - Jhon Sebastian Oviedo Ortiz
AU - Jasmin Seibert
AU - Stefan Bräse
AU - Jeanne Crassous
AU - Xiao-Hong Zhang
AU - Eli Zysman-Colman
PY - 2026
DA - 2026/09/03
JO - Chemical Science
DO - 10.1039/d6sc04906k
UR - https://hal.science/hal-05742046v1
AB - Multi-resonant thermally activated delayed fluorescence (MR-TADF) emitters offer an attractive solution for the fabrication of colour-saturated organic light-emitting diodes (OLEDs). Still, their rigid frameworks often lead to slow reverse intersystem crossing and aggregation-caused quenching. To address these challenges and simultaneously introduce chiroptical properties in solution-processable materials, here we present the first examples of chiral intramolecular Förster resonance energy transfer (FRET) MR-TADF dendrimers, CzPBN-CzBN and CzPBA-CzBN. These emitters combine an MR-TADF core with chiral paracyclophane (CzP)-based donor dendrons linked to different acceptor units, benzonitrile for CzPBN-CzBN and benzoic acid for CzPBA-CzBN. While both dendrimers show narrowband TADF emission, the nature of the acceptor impacts their chiroptical properties. Specifically, CzPBA-CzBN exhibits circularly polarised luminescence (CPL), whereas CzPBN-CzBN does not due to a weaker circular dichroism signal. Conversely, in solution-processed hyperfluorescent (HF) OLEDs, the device with CzPBN-CzBN achieved a superior maximum external quantum efficiency (EQEmax) of 19.7% and lower efficiency roll-off (EQE of 18.9% at 1000 cd m‑2) compared to the device with CzPBA-CzBN (EQEmax/1000 = 17.2/16.5%). These findings reveal an intrinsic trade-off between CPL response and HF device performance, demonstrating how precise modulation of the excited-state manifold via acceptor engineering can be used to tailor the properties of intramolecular sensitised TADF emitters.
SN - 2041-6520
SN - 2041-6539
ER -