Exploring the impact of the presence of 9,9’-spirobifluorene moieties on the performance of carbonyl-based multiresonant thermally activated delayed fluorescence organic light-emitting diodes

Janine Julia Haug; Sen Wu; Hassan Hafeez; Maximilian  Schustek; Mahni Fatahi; Yannik T. Woordes; Martin  Nieger; Olaf  Fuhr; Burkhard  Luy; Ifor D. W. Samuel; Stefan  Bräse; Eli Zysman-Colman

doi:10.1002/adom.202502118

Exploring the impact of the presence of 9,9’-spirobifluorene moieties on the performance of carbonyl-based multiresonant thermally activated delayed fluorescence organic light-emitting diodes

Janine Julia Haug
, Sen Wu
, Hassan Hafeez
, Maximilian Schustek
, Mahni Fatahi
, Yannik T. Woordes
, Martin Nieger
, Olaf Fuhr
, Burkhard Luy
, Ifor D. W. Samuel^*
, Stefan Bräse^*
, Eli Zysman-Colman^*

^*Corresponding author for this work

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

Abstract

The impact of the decoration of the multiresonant thermally activated delayed fluorescence (MR-TADF) core DiKTa with 9,9′-spirobifluorene (SBF) groups is investigated with respect to the impact of number, position, and incorporation-type of the SBF unit on the photophysical and optoelectronic properties. This approach allows for the development of narrowband, high-efficiency organic light emitting diodes (OLEDs) with moderate efficiency roll-off. The MR-TADF emitters DiKTaSBF, 3-SBF-DiKTa, 7-SBF-DiKTa, and 7-SBF-DiKTaSBF, differ in the number, position, and incorporation-type of the SBF unit. Sky-blue OLEDs with DiKTaSBF and 3-SBF-DiKTa show superior performance with maximal external quantum efficiencies (EQE_max) of 26.1 and 27.0%, respectively, while all four families of OLEDs show a moderate efficiency roll-off. Narrowband emissions with full-width at half maximum (FWHM) of 32 and 35 nm are observed for 7-modified emitters, whereas for the devices with emitters containing SBF groups at the 3-position show a broadened emission, with FWHM of ≈50 nm. These findings highlight the effect of the regiochemistry of the SBF group on the optoelectronic properties and the corresponding impact on the performance of the OLEDs.

Original language	English
Article number	e02118
Number of pages	14
Journal	Advanced Optical Materials
Volume	Early View
Early online date	14 Nov 2025
DOIs	https://doi.org/10.1002/adom.202502118
Publication status	E-pub ahead of print - 14 Nov 2025

Keywords

Multiresonant thermally activated delayed fluorescence
Organic light-emitting diodes
Spirobifluorene
Structure-property relationship
Thermally activated delayed fluorescence

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1 Finished
3 Active

SolOLED: TADF Dendrimers for Highly Efficient Solution-Processed OLEDs
Zysman-Colman, E. (PI)
EPSRC
1/01/25 → 31/12/29
Project: Fellowship
Allan Watson Programme Grant: Boron: Beyond the Reagent
Watson, A. (PI), Morris, R. (CoI), Smith, A. (CoI) & Zysman-Colman, E. (CoI)
UK Research and Innovation
1/05/23 → 30/04/28
Project: Standard
TADF Solutions: TADF SOLUTIONS: addressing the challenges of high-performance solution-processed OLEDs using sustainable materials
Zysman-Colman, E. (PI)
UKRI (EU)
1/10/22 → 30/09/26
Project: Standard

Exploring the Impact of the Presence of 9,9’-Spirobifluorene Moieties on the Performance of Carbonyl-based Multiresonant Thermally Activated Delayed Fluorescence Organic Light- Emitting Diodes (dataset)
Haug, J. J. (Creator), Wu, S. (Creator), Hafeez, H. (Creator), Schustek, M. (Creator), Fatahi, M. (Creator), Woordes, Y. T. (Creator), Nieger, M. (Creator), Fuhr, O. (Creator), Luy, B. (Creator), Samuel, I. D. W. (Creator), Bräse, S. (Creator) & Zysman-Colman, E. (Creator), University of St Andrews, 17 Nov 2025
DOI: 10.17630/d624631f-8adb-4a88-88e9-0e6f08a9671c
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Haug, J. J., Wu, S., Hafeez, H., Schustek, M., Fatahi, M., Woordes, Y. T., Nieger, M., Fuhr, O., Luy, B., Samuel, I. D. W., Bräse, S., & Zysman-Colman, E. (2025). Exploring the impact of the presence of 9,9’-spirobifluorene moieties on the performance of carbonyl-based multiresonant thermally activated delayed fluorescence organic light-emitting diodes. Advanced Optical Materials, Early View, Article e02118. Advance online publication. https://doi.org/10.1002/adom.202502118

@article{1397b58f81e647f1969b99a3dbebbbf0,

title = "Exploring the impact of the presence of 9,9{\textquoteright}-spirobifluorene moieties on the performance of carbonyl-based multiresonant thermally activated delayed fluorescence organic light-emitting diodes",

abstract = "The impact of the decoration of the multiresonant thermally activated delayed fluorescence (MR-TADF) core DiKTa with 9,9′-spirobifluorene (SBF) groups is investigated with respect to the impact of number, position, and incorporation-type of the SBF unit on the photophysical and optoelectronic properties. This approach allows for the development of narrowband, high-efficiency organic light emitting diodes (OLEDs) with moderate efficiency roll-off. The MR-TADF emitters DiKTaSBF, 3-SBF-DiKTa, 7-SBF-DiKTa, and 7-SBF-DiKTaSBF, differ in the number, position, and incorporation-type of the SBF unit. Sky-blue OLEDs with DiKTaSBF and 3-SBF-DiKTa show superior performance with maximal external quantum efficiencies (EQEmax) of 26.1 and 27.0\%, respectively, while all four families of OLEDs show a moderate efficiency roll-off. Narrowband emissions with full-width at half maximum (FWHM) of 32 and 35 nm are observed for 7-modified emitters, whereas for the devices with emitters containing SBF groups at the 3-position show a broadened emission, with FWHM of ≈50 nm. These findings highlight the effect of the regiochemistry of the SBF group on the optoelectronic properties and the corresponding impact on the performance of the OLEDs.",

keywords = "Multiresonant thermally activated delayed fluorescence, Organic light-emitting diodes, Spirobifluorene, Structure-property relationship, Thermally activated delayed fluorescence",

author = "Haug, \{Janine Julia\} and Sen Wu and Hassan Hafeez and Maximilian Schustek and Mahni Fatahi and Woordes, \{Yannik T.\} and Martin Nieger and Olaf Fuhr and Burkhard Luy and Samuel, \{Ifor D. W.\} and Stefan Br{\"a}se and Eli Zysman-Colman",

note = "Funding: S.W. thanks the China Scholarship Council (201906250199). The authors acknowledge support by the state of Baden-W{\"u}rttemberg through bwHPC and the German Research Foundation (DFG) through grant no INST 40/575-1 FUGG (JUSTUS 2 cluster). This project has been partly funded by the European Union Horizon 2021 research and innovation programme under grant agreement No. 101073045 (TADFsolutions) and the EPSRC grant EP/X026175/1. We thank the EPSRC (EP/Z535291/1, EP/W007517/1, and EP/W015137/1) for financial support.",

year = "2025",

month = nov,

day = "14",

doi = "10.1002/adom.202502118",

language = "English",

volume = "Early View",

journal = "Advanced Optical Materials",

issn = "2195-1071",

publisher = "John Wiley \& Sons, Ltd",

}

Haug, JJ, Wu, S, Hafeez, H, Schustek, M, Fatahi, M, Woordes, YT, Nieger, M, Fuhr, O, Luy, B, Samuel, IDW, Bräse, S & Zysman-Colman, E 2025, 'Exploring the impact of the presence of 9,9’-spirobifluorene moieties on the performance of carbonyl-based multiresonant thermally activated delayed fluorescence organic light-emitting diodes', Advanced Optical Materials, vol. Early View, e02118. https://doi.org/10.1002/adom.202502118

Exploring the impact of the presence of 9,9’-spirobifluorene moieties on the performance of carbonyl-based multiresonant thermally activated delayed fluorescence organic light-emitting diodes. / Haug, Janine Julia; Wu, Sen; Hafeez, Hassan et al.
In: Advanced Optical Materials, Vol. Early View, e02118, 14.11.2025.

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

TY - JOUR

T1 - Exploring the impact of the presence of 9,9’-spirobifluorene moieties on the performance of carbonyl-based multiresonant thermally activated delayed fluorescence organic light-emitting diodes

AU - Haug, Janine Julia

AU - Wu, Sen

AU - Hafeez, Hassan

AU - Schustek, Maximilian

AU - Fatahi, Mahni

AU - Woordes, Yannik T.

AU - Nieger, Martin

AU - Fuhr, Olaf

AU - Luy, Burkhard

AU - Samuel, Ifor D. W.

AU - Bräse, Stefan

AU - Zysman-Colman, Eli

N1 - Funding: S.W. thanks the China Scholarship Council (201906250199). 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 2 cluster). This project has been partly funded by the European Union Horizon 2021 research and innovation programme under grant agreement No. 101073045 (TADFsolutions) and the EPSRC grant EP/X026175/1. We thank the EPSRC (EP/Z535291/1, EP/W007517/1, and EP/W015137/1) for financial support.

PY - 2025/11/14

Y1 - 2025/11/14

N2 - The impact of the decoration of the multiresonant thermally activated delayed fluorescence (MR-TADF) core DiKTa with 9,9′-spirobifluorene (SBF) groups is investigated with respect to the impact of number, position, and incorporation-type of the SBF unit on the photophysical and optoelectronic properties. This approach allows for the development of narrowband, high-efficiency organic light emitting diodes (OLEDs) with moderate efficiency roll-off. The MR-TADF emitters DiKTaSBF, 3-SBF-DiKTa, 7-SBF-DiKTa, and 7-SBF-DiKTaSBF, differ in the number, position, and incorporation-type of the SBF unit. Sky-blue OLEDs with DiKTaSBF and 3-SBF-DiKTa show superior performance with maximal external quantum efficiencies (EQEmax) of 26.1 and 27.0%, respectively, while all four families of OLEDs show a moderate efficiency roll-off. Narrowband emissions with full-width at half maximum (FWHM) of 32 and 35 nm are observed for 7-modified emitters, whereas for the devices with emitters containing SBF groups at the 3-position show a broadened emission, with FWHM of ≈50 nm. These findings highlight the effect of the regiochemistry of the SBF group on the optoelectronic properties and the corresponding impact on the performance of the OLEDs.

AB - The impact of the decoration of the multiresonant thermally activated delayed fluorescence (MR-TADF) core DiKTa with 9,9′-spirobifluorene (SBF) groups is investigated with respect to the impact of number, position, and incorporation-type of the SBF unit on the photophysical and optoelectronic properties. This approach allows for the development of narrowband, high-efficiency organic light emitting diodes (OLEDs) with moderate efficiency roll-off. The MR-TADF emitters DiKTaSBF, 3-SBF-DiKTa, 7-SBF-DiKTa, and 7-SBF-DiKTaSBF, differ in the number, position, and incorporation-type of the SBF unit. Sky-blue OLEDs with DiKTaSBF and 3-SBF-DiKTa show superior performance with maximal external quantum efficiencies (EQEmax) of 26.1 and 27.0%, respectively, while all four families of OLEDs show a moderate efficiency roll-off. Narrowband emissions with full-width at half maximum (FWHM) of 32 and 35 nm are observed for 7-modified emitters, whereas for the devices with emitters containing SBF groups at the 3-position show a broadened emission, with FWHM of ≈50 nm. These findings highlight the effect of the regiochemistry of the SBF group on the optoelectronic properties and the corresponding impact on the performance of the OLEDs.

KW - Multiresonant thermally activated delayed fluorescence

KW - Organic light-emitting diodes

KW - Spirobifluorene

KW - Structure-property relationship

KW - Thermally activated delayed fluorescence

U2 - 10.1002/adom.202502118

DO - 10.1002/adom.202502118

M3 - Article

SN - 2195-1071

VL - Early View

JO - Advanced Optical Materials

JF - Advanced Optical Materials

M1 - e02118

ER -

Exploring the impact of the presence of 9,9’-spirobifluorene moieties on the performance of carbonyl-based multiresonant thermally activated delayed fluorescence organic light-emitting diodes

Abstract

Keywords

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Projects

SolOLED: TADF Dendrimers for Highly Efficient Solution-Processed OLEDs

Allan Watson Programme Grant: Boron: Beyond the Reagent

TADF Solutions: TADF SOLUTIONS: addressing the challenges of high-performance solution-processed OLEDs using sustainable materials

Datasets

Exploring the Impact of the Presence of 9,9’-Spirobifluorene Moieties on the Performance of Carbonyl-based Multiresonant Thermally Activated Delayed Fluorescence Organic Light- Emitting Diodes (dataset)

Cite this