Influence of regioisomerism in bis(terpyridine) based exciplexes with delayed fluorescence
Abstract
Exciplexes of individual electron donor and acceptor molecules are a promising approach to utilizing otherwise non-emissive triplet states in optoelectronic applications. In this work, we synthesize a series of bis(terpyridine) pyrimidine (BTP) isomers and employ them as electron acceptors in complexes with tris(4-carbazoyl-9-ylphenyl)amine (TCTA). We show that these TCTA : BTP complexes produce thermally activated delayed fluorescence (TADF) by exciplex emission, and we investigate the influence of the nitrogen position in the pyridine on the optical and electronic properties of the exciplex. The molecular arrangement of the complex is studied using scanning tunneling microscopy (STM) as well as classical force field and density functional theory (DFT) simulations. Finally, we fabricate organic light-emitting diodes (OLEDs) with maximum external quantum efficiencies ranging between 0.5% and 2% – depending on the BTP isomer.
Citation
Schleper , A L , Hillebrandt , S , Bannwarth , C , Mischok , A , Kwon , S , Buchner , F , Tenopala-Carmona , F , Behm , R J , Goll , F D , Welscher , P J , Usselmann , M , Ziener , U , Gather , M C & Kuehne , A J C 2022 , ' Influence of regioisomerism in bis(terpyridine) based exciplexes with delayed fluorescence ' , Journal of Materials Chemistry C , vol. 10 , no. 19 , pp. 7699-7706 . https://doi.org/10.1039/d2tc00800a
Publication
Journal of Materials Chemistry C
Status
Peer reviewed
ISSN
2050-7526Type
Journal article
Description
Funding: A. L. S. acknowledges financial support through a Cusanuswerk scholarship. The authors acknowledge support by the state of Baden-Württemberg through bwHPC and the German Research Foundation (DFG) through grant no INST 40/575-1 FUGG (JUSTUS and JUSTUS 2 cluster). M. C. G. acknowledges support from the Leverhulme Trust (RPG-2016047) and the Alexander von Humboldt Stiftung through the Humboldt-Professorship. A. M. acknowledges support from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 101023743 (PolDev). C. B. acknowledges funding by the BMBF and the Ministry of Culture and Science of the German State of North Rhine-Westphalia (MKW) under the Excellence Strategy of the Federal Government and the Länder.Collections
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