Substitution effects on a new pyridylbenzimidazole acceptor for thermally activated delayed fluorescence and their use in organic light-emitting diodes

David Hall; Pachaiyappan Rajamalli; Eimantas Duda; Subeesh Madayanad Suresh; Francesco Rodella; Sergey Bagnich; Cameron Lewis Carpenter-Warren; David Bradford Cordes; Alexandra Martha Zoya Slawin; Peter Strohriegl; David Beljonne; Anna Köhler; Yoann Olivier; Eli Zysman-Colman

doi:10.1002/adom.202100846

Substitution effects on a new pyridylbenzimidazole acceptor for thermally activated delayed fluorescence and their use in organic light-emitting diodes

David Hall, Pachaiyappan Rajamalli, Eimantas Duda, Subeesh Madayanad Suresh, Francesco Rodella, Sergey Bagnich, Cameron Lewis Carpenter-Warren, David Bradford Cordes, Alexandra Martha Zoya Slawin, Peter Strohriegl, David Beljonne, Anna Köhler, Yoann Olivier, Eli Zysman-Colman

Research output: Contribution to journal › Article › peer-review

Abstract

In this work a new acceptor is used for use in thermally activated delayed fluorescence (TADF) emitters, pyridylbenzimidazole, which when coupled with phenoxazine allows efficient TADF to occur. N-functionalization of the benzimidazole using methyl, phenyl, and tert-butyl groups permits color tuning and suppression of aggregation-caused quenching (ACQ) with minimal impact on the TADF efficiency. The functionalized derivatives support a higher doping of 7 wt% before a fall-off in photoluminescence quantum yields is observed, in contrast with the parent compound, which undergoes ACQ at doping concentrations greater than 1 wt%. Complex conformational dynamics, reflected in the time-resolved decay profile, is found. The singlet−triplet energy gap, ΔE_ST, is modulated by N-substituents of the benzimidazole and ranges of between 0.22 and 0.32 eV in doped films. Vacuum-deposited organic light-emitting diodes, prepared using three of the four analogs, show maximum external quantum efficiencies, EQE_max, of 23.9%, 22.2%, and 18.6% for BIm(Me)PyPXZ, BIm(Ph)PyPXZ, and BImPyPXZ, respectively, with a correlated and modest efficiency roll-off at 100 cd m^–2 of 19% 13%, and 24% of the EQE_max, respectively.

Original language	English
Article number	2100846
Number of pages	13
Journal	Advanced Optical Materials
Volume	9
Issue number	20
Early online date	2 Aug 2021
DOIs	https://doi.org/10.1002/adom.202100846
Publication status	Published - 18 Oct 2021

Keywords

DFT calculation
Organic light-emitting diodes
Photophysics
Pryidylbenzimidazole
Thermally activated delayed fluorescence

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Hall_2021_AOM_Substitution-Effects_CC
Copyright © 2021 The Authors. Advanced Optical Materials published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Final published version, 6.37 MBLicence: CC BY-NC

H2020 MSCA IF 2018 (Subeesh Suresh): H2020 MSCA IF 2018 (Subeesh Suresh )
Zysman-Colman, E. (PI)
European Commission
1/04/19 → 31/03/21
Project: Fellowship
H2020 - ITN ELI ZYSMAN-COLMAN: H2020 MSCA ITN TADFlife
Zysman-Colman, E. (PI)
European Commission
1/10/18 → 30/09/22
Project: Standard
DENTADFE: DENTADFE
Zysman-Colman, E. (PI)
European Commission
1/03/17 → 28/02/19
Project: Fellowship

Substitution Effects on a New Pyridylbenzimidazole Acceptor for Thermally Activated Delayed Fluorescence and Their Use in Organic Light-Emitting Diodes (dataset)
Hall, D. (Creator), Rajamalli, P. (Creator), Duda, E. (Creator), Madayanad Suresh, S. (Creator), Rodella, F. (Creator), Bagnich, S. (Creator), Carpenter-Warren, C. L. (Creator), Cordes, D. B. (Creator), Slawin, A. M. Z. (Creator), Strohriegl, P. (Creator), Beljonne, D. (Creator), Köhler, A. (Creator), Olivier, Y. (Creator) & Zysman-Colman, E. (Creator), University of St Andrews, 8 Aug 2021
DOI: 10.17630/19a1218e-1aea-4331-b65b-103b15b9699c
Dataset

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Hall, D., Rajamalli, P., Duda, E., Madayanad Suresh, S., Rodella, F., Bagnich, S., Carpenter-Warren, C. L., Cordes, D. B., Slawin, A. M. Z., Strohriegl, P., Beljonne, D., Köhler, A., Olivier, Y., & Zysman-Colman, E. (2021). Substitution effects on a new pyridylbenzimidazole acceptor for thermally activated delayed fluorescence and their use in organic light-emitting diodes. Advanced Optical Materials, 9(20), Article 2100846. https://doi.org/10.1002/adom.202100846

@article{4c15b52ad48442f3949de144cccafec7,

title = "Substitution effects on a new pyridylbenzimidazole acceptor for thermally activated delayed fluorescence and their use in organic light-emitting diodes",

abstract = "In this work a new acceptor is used for use in thermally activated delayed fluorescence (TADF) emitters, pyridylbenzimidazole, which when coupled with phenoxazine allows efficient TADF to occur. N-functionalization of the benzimidazole using methyl, phenyl, and tert-butyl groups permits color tuning and suppression of aggregation-caused quenching (ACQ) with minimal impact on the TADF efficiency. The functionalized derivatives support a higher doping of 7 wt% before a fall-off in photoluminescence quantum yields is observed, in contrast with the parent compound, which undergoes ACQ at doping concentrations greater than 1 wt%. Complex conformational dynamics, reflected in the time-resolved decay profile, is found. The singlet−triplet energy gap, ΔEST, is modulated by N-substituents of the benzimidazole and ranges of between 0.22 and 0.32 eV in doped films. Vacuum-deposited organic light-emitting diodes, prepared using three of the four analogs, show maximum external quantum efficiencies, EQEmax, of 23.9%, 22.2%, and 18.6% for BIm(Me)PyPXZ, BIm(Ph)PyPXZ, and BImPyPXZ, respectively, with a correlated and modest efficiency roll-off at 100 cd m–2 of 19% 13%, and 24% of the EQEmax, respectively.",

keywords = "DFT calculation, Organic light-emitting diodes, Photophysics, Pryidylbenzimidazole, Thermally activated delayed fluorescence",

author = "David Hall and Pachaiyappan Rajamalli and Eimantas Duda and {Madayanad Suresh}, Subeesh and Francesco Rodella and Sergey Bagnich and Carpenter-Warren, {Cameron Lewis} and Cordes, {David Bradford} and Slawin, {Alexandra Martha Zoya} and Peter Strohriegl and David Beljonne and Anna K{\"o}hler and Yoann Olivier and Eli Zysman-Colman",

note = "The St Andrews team would like to thank the Leverhulme Trust (RPG-2016-047) for financial support. P.R. acknowledges support from a Marie Sk{\l}odowska-Curie Individual Fellowship (MCIF; No. 749557). S.M.S acknowledges support from the Marie Sk{\l}odowska-Curie Individual Fellowship, grant 27 agreement no. 838885 (NarrowbandSSL). Computational resources have been provided by the Consortium des {\'E}quipements de Calcul Intensif (C{\'E}CI), funded by the Fonds de la Recherche Scientifiques de Belgique (F.R.S.-FNRS) under Grant No. 2.5020.11, as well as the Tier-1 supercomputer of the F{\'e}d{\'e}ration Wallonie-Bruxelles, infrastructure funded by the Walloon Region under the grant agreement n1117545. We acknowledge support from the European Union{\textquoteright}s Horizon 2020 research and innovation programme under the ITN TADFlife (GA 812872). Y.O. acknowledges funding by the Fonds de la Recherche Scientifique-FNRS under Grant n° F.4534.21 (MIS-IMAGINE). D.B. is a FNRS Research Director.",

year = "2021",

month = oct,

day = "18",

doi = "10.1002/adom.202100846",

language = "English",

volume = "9",

journal = "Advanced Optical Materials",

issn = "2195-1071",

publisher = "John Wiley & Sons, Ltd",

number = "20",

}

Hall, D, Rajamalli, P, Duda, E, Madayanad Suresh, S, Rodella, F, Bagnich, S, Carpenter-Warren, CL, Cordes, DB , Slawin, AMZ, Strohriegl, P, Beljonne, D, Köhler, A, Olivier, Y & Zysman-Colman, E 2021, 'Substitution effects on a new pyridylbenzimidazole acceptor for thermally activated delayed fluorescence and their use in organic light-emitting diodes', Advanced Optical Materials, vol. 9, no. 20, 2100846. https://doi.org/10.1002/adom.202100846

TY - JOUR

T1 - Substitution effects on a new pyridylbenzimidazole acceptor for thermally activated delayed fluorescence and their use in organic light-emitting diodes

AU - Hall, David

AU - Rajamalli, Pachaiyappan

AU - Duda, Eimantas

AU - Madayanad Suresh, Subeesh

AU - Rodella, Francesco

AU - Bagnich, Sergey

AU - Carpenter-Warren, Cameron Lewis

AU - Cordes, David Bradford

AU - Slawin, Alexandra Martha Zoya

AU - Strohriegl, Peter

AU - Beljonne, David

AU - Köhler, Anna

AU - Olivier, Yoann

AU - Zysman-Colman, Eli

N1 - The St Andrews team would like to thank the Leverhulme Trust (RPG-2016-047) for financial support. P.R. acknowledges support from a Marie Skłodowska-Curie Individual Fellowship (MCIF; No. 749557). S.M.S acknowledges support from the Marie Skłodowska-Curie Individual Fellowship, grant 27 agreement no. 838885 (NarrowbandSSL). Computational resources have been provided by the Consortium des Équipements de Calcul Intensif (CÉCI), funded by the Fonds de la Recherche Scientifiques de Belgique (F.R.S.-FNRS) under Grant No. 2.5020.11, as well as the Tier-1 supercomputer of the Fédération Wallonie-Bruxelles, infrastructure funded by the Walloon Region under the grant agreement n1117545. We acknowledge support from the European Union’s Horizon 2020 research and innovation programme under the ITN TADFlife (GA 812872). Y.O. acknowledges funding by the Fonds de la Recherche Scientifique-FNRS under Grant n° F.4534.21 (MIS-IMAGINE). D.B. is a FNRS Research Director.

PY - 2021/10/18

Y1 - 2021/10/18

N2 - In this work a new acceptor is used for use in thermally activated delayed fluorescence (TADF) emitters, pyridylbenzimidazole, which when coupled with phenoxazine allows efficient TADF to occur. N-functionalization of the benzimidazole using methyl, phenyl, and tert-butyl groups permits color tuning and suppression of aggregation-caused quenching (ACQ) with minimal impact on the TADF efficiency. The functionalized derivatives support a higher doping of 7 wt% before a fall-off in photoluminescence quantum yields is observed, in contrast with the parent compound, which undergoes ACQ at doping concentrations greater than 1 wt%. Complex conformational dynamics, reflected in the time-resolved decay profile, is found. The singlet−triplet energy gap, ΔEST, is modulated by N-substituents of the benzimidazole and ranges of between 0.22 and 0.32 eV in doped films. Vacuum-deposited organic light-emitting diodes, prepared using three of the four analogs, show maximum external quantum efficiencies, EQEmax, of 23.9%, 22.2%, and 18.6% for BIm(Me)PyPXZ, BIm(Ph)PyPXZ, and BImPyPXZ, respectively, with a correlated and modest efficiency roll-off at 100 cd m–2 of 19% 13%, and 24% of the EQEmax, respectively.

AB - In this work a new acceptor is used for use in thermally activated delayed fluorescence (TADF) emitters, pyridylbenzimidazole, which when coupled with phenoxazine allows efficient TADF to occur. N-functionalization of the benzimidazole using methyl, phenyl, and tert-butyl groups permits color tuning and suppression of aggregation-caused quenching (ACQ) with minimal impact on the TADF efficiency. The functionalized derivatives support a higher doping of 7 wt% before a fall-off in photoluminescence quantum yields is observed, in contrast with the parent compound, which undergoes ACQ at doping concentrations greater than 1 wt%. Complex conformational dynamics, reflected in the time-resolved decay profile, is found. The singlet−triplet energy gap, ΔEST, is modulated by N-substituents of the benzimidazole and ranges of between 0.22 and 0.32 eV in doped films. Vacuum-deposited organic light-emitting diodes, prepared using three of the four analogs, show maximum external quantum efficiencies, EQEmax, of 23.9%, 22.2%, and 18.6% for BIm(Me)PyPXZ, BIm(Ph)PyPXZ, and BImPyPXZ, respectively, with a correlated and modest efficiency roll-off at 100 cd m–2 of 19% 13%, and 24% of the EQEmax, respectively.

KW - DFT calculation

KW - Organic light-emitting diodes

KW - Photophysics

KW - Pryidylbenzimidazole

KW - Thermally activated delayed fluorescence

U2 - 10.1002/adom.202100846

DO - 10.1002/adom.202100846

M3 - Article

SN - 2195-1071

VL - 9

JO - Advanced Optical Materials

JF - Advanced Optical Materials

IS - 20

M1 - 2100846

ER -

Substitution effects on a new pyridylbenzimidazole acceptor for thermally activated delayed fluorescence and their use in organic light-emitting diodes

Abstract

Keywords

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Projects

H2020 MSCA IF 2018 (Subeesh Suresh): H2020 MSCA IF 2018 (Subeesh Suresh )

H2020 - ITN ELI ZYSMAN-COLMAN: H2020 MSCA ITN TADFlife

DENTADFE: DENTADFE

Datasets

Substitution Effects on a New Pyridylbenzimidazole Acceptor for Thermally Activated Delayed Fluorescence and Their Use in Organic Light-Emitting Diodes (dataset)

Cite this