All Outputs (271)

Isomeric modulation of thermally activated delayed fluorescence in dibenzo[ a, c ]phenazine-based (deep) red emitters † (2024)
Journal Article
Brebels, S., Cardeynaels, T., Jackers, L., Kuila, S., Penxten, H., Salthouse, R. J., …Maes, W. (2024). Isomeric modulation of thermally activated delayed fluorescence in dibenzo[ a, c ]phenazine-based (deep) red emitters †. Journal of Materials Chemistry C Materials for optical and electronic devices, https://doi.org/10.1039/d4tc01214c

A series of four emissive regio-isomers are synthesized based on the dibenzo[a, c]phenazine-11,12-dicarbonitrile (DBPzCN) acceptor scaffold and a triphenylamine (TPA) donor. Density functional theory is utilized to compare the relative differences in... Read More about Isomeric modulation of thermally activated delayed fluorescence in dibenzo[ a, c ]phenazine-based (deep) red emitters †.

Key requirements for ultraefficient sensitization in hyperfluorescence organic light-emitting diodes (2024)
Journal Article
Stavrou, K., Franca, L. G., Danos, A., & Monkman, A. P. (2024). Key requirements for ultraefficient sensitization in hyperfluorescence organic light-emitting diodes. Nature Photonics, 18(6), 554-561. https://doi.org/10.1038/s41566-024-01395-1

Blue organic light-emitting diode (OLED) technology requires further advancements, and hyperfluorescent (HF) OLEDs have emerged as a promising solution to address stability and colour-purity concerns. A key factor influencing the performance of HF-OL... Read More about Key requirements for ultraefficient sensitization in hyperfluorescence organic light-emitting diodes.

Exploring the Early Time Behavior of the Excited States of an Archetype Thermally Activated Delayed Fluorescence Molecule (2024)
Journal Article
Franca, L., Danos, A., Saxena, R., Kuila, S., Stavrou, K., Li, C., …Monkman, A. P. (2024). Exploring the Early Time Behavior of the Excited States of an Archetype Thermally Activated Delayed Fluorescence Molecule. Journal of Physical Chemistry Letters, 15(6), 1734-1740. https://doi.org/10.1021/acs.jpclett.4c00030

Optical pump–probe techniques allow for an in-depth study of dark excited states. Here, we utilize them to map and gain insights into the excited states involved in the thermally activated delayed fluorescence (TADF) mechanism of a benchmark TADF emi... Read More about Exploring the Early Time Behavior of the Excited States of an Archetype Thermally Activated Delayed Fluorescence Molecule.

Spin-Vibronic Intersystem Crossing and Molecular Packing Effects in Heavy Atom Free Organic Phosphor. (2024)
Journal Article
Pope, T., Eng, J., Monkman, A., & Penfold, T. J. (2024). Spin-Vibronic Intersystem Crossing and Molecular Packing Effects in Heavy Atom Free Organic Phosphor. Journal of Chemical Theory and Computation, 20(3), 1337–1346. https://doi.org/10.1021/acs.jctc.3c01220

We present a detailed investigation into the excited state properties of a planar symmetric azatriangulenetrione, HTANGO, which has received significant interest due to its high solid-state phosphorescence quantum yield and therefore potential as a... Read More about Spin-Vibronic Intersystem Crossing and Molecular Packing Effects in Heavy Atom Free Organic Phosphor..

Peripheral halogen atoms in multi-resonant thermally activated delayed fluorescence emitters: the role of heavy atoms in intermolecular interactions and spin orbit coupling (2023)
Journal Article
Miranda-Salinas, H., Wang, J., Danos, A., Matulaitis, T., Stavrou, K., Monkman, A. P., & Zysman-Colman, E. (2024). Peripheral halogen atoms in multi-resonant thermally activated delayed fluorescence emitters: the role of heavy atoms in intermolecular interactions and spin orbit coupling. Journal of Materials Chemistry C Materials for optical and electronic devices, 12(6), 1996-2006. https://doi.org/10.1039/d3tc04394k

Multi-resonant thermally activated delayed fluorescence materials (MR-TADF) can show narrow-band emission with high photoluminescence quantum efficiency, desirable for applications in organic light emitting diodes (OLEDS). However, they frequently su... Read More about Peripheral halogen atoms in multi-resonant thermally activated delayed fluorescence emitters: the role of heavy atoms in intermolecular interactions and spin orbit coupling.

Intramolecular locking and coumarin insertion: a stepwise approach for TADF design (2023)
Journal Article
Paredis, S., Cardeynaels, T., Brebels, S., Deckers, J., Kuila, S., Lathouwers, A., …Maes, W. (2023). Intramolecular locking and coumarin insertion: a stepwise approach for TADF design. Physical Chemistry Chemical Physics, https://doi.org/10.1039/d3cp03695b

Three novel TADF (thermally activated delayed fluorescence) emitters based on the well-studied Qx-Ph-DMAC fluorophore are designed and synthesized. The photophysical properties of these materials are studied from a theoretical and experimental point... Read More about Intramolecular locking and coumarin insertion: a stepwise approach for TADF design.

Covalently linked pyrene antennas for optically dense yet aggregation-resistant light-harvesting systems (2023)
Journal Article
Salah, L., Makhseed, S., Ghazal, B., Abdel Nazeer, A., Etherington, M. K., Ponseca Jr., C. S., …Shuaib, A. (2023). Covalently linked pyrene antennas for optically dense yet aggregation-resistant light-harvesting systems. Physical Chemistry Chemical Physics, 25(36), 24878-24882. https://doi.org/10.1039/d3cp02586a

In this study we present a novel energy transfer material inspired by natural light-harvesting antenna arrays, zinc(II) phthalocyanine-pyrene (ZnPcPy). The ZnPcPy system facilitates energy transfer from 16 covalently linked pyrene (Py) donor chromoph... Read More about Covalently linked pyrene antennas for optically dense yet aggregation-resistant light-harvesting systems.

Quantifying Molecular Disorder in Tri-Isopropyl Silane (TIPS) Pentacene Using Variable Coherence Transmission Electron Microscopy (2023)
Journal Article
Alanazi, F., Eggeman, A. S., Stavrou, K., Danos, A., Monkman, A. P., & Mendis, B. G. (2023). Quantifying Molecular Disorder in Tri-Isopropyl Silane (TIPS) Pentacene Using Variable Coherence Transmission Electron Microscopy. Journal of Physical Chemistry Letters, 14(36), 8183-8190. https://doi.org/10.1021/acs.jpclett.3c01344

Structural disorder in molecular crystals is a fundamental limitation for achieving high charge carrier mobilities. Quantifying and uncovering the mechanistic origins of disorder are, however, extremely challenging. Here we use variable coherence tra... Read More about Quantifying Molecular Disorder in Tri-Isopropyl Silane (TIPS) Pentacene Using Variable Coherence Transmission Electron Microscopy.

Rational design of dibenzo[a,c]phenazine-derived isomeric thermally activated delayed fluorescence luminophores for efficient orange-red organic light-emitting diodes (2023)
Journal Article
Ye, H., Yang, J., Stavrou, K., Li, M., Liu, F., Li, F., …Monkman, A. P. (2023). Rational design of dibenzo[a,c]phenazine-derived isomeric thermally activated delayed fluorescence luminophores for efficient orange-red organic light-emitting diodes. Dyes and Pigments, 219, Article 111568. https://doi.org/10.1016/j.dyepig.2023.111568

It is an immense challenge to develop efficient long-wavelength (orange-to-red) thermally activated delayed fluorescence (TADF) materials due to the increasing nonradiative decay rates following the energy-gap law. Herein, two pairs of asymmetric iso... Read More about Rational design of dibenzo[a,c]phenazine-derived isomeric thermally activated delayed fluorescence luminophores for efficient orange-red organic light-emitting diodes.

Azaborine as a Versatile Weak Donor for Thermally Activated Delayed Fluorescence (2023)
Journal Article
Sudhakar, P., Kuila, S., Stavrou, K., Danos, A., Slawin, A. M., Monkman, A., & Zysman-Colman, E. (2023). Azaborine as a Versatile Weak Donor for Thermally Activated Delayed Fluorescence. ACS Applied Materials and Interfaces, 15(21), 25806-25818. https://doi.org/10.1021/acsami.3c05409

Extensive research has been devoted to the development of thermally activated delayed fluorescence emitters, especially those showing pure-blue emission for use in lighting and fullcolor display applications. Towards that goal, herein we report a nov... Read More about Azaborine as a Versatile Weak Donor for Thermally Activated Delayed Fluorescence.

Balanced Energy Gaps as a Key Design Rule for Solution‐Phase Organic Room Temperature Phosphorescence (2023)
Journal Article
Paredis, S., Cardeynaels, T., Kuila, S., Deckers, J., Van Landeghem, M., Vandewal, K., …Maes, W. (2023). Balanced Energy Gaps as a Key Design Rule for Solution‐Phase Organic Room Temperature Phosphorescence. Chemistry - A European Journal, https://doi.org/10.1002/chem.202301369

Metal-free organic emitters that display solution-phase room temperature phosphorescence (sRTP) remain exceedingly rare. Here, we investigate the structural and photophysical properties that support sRTP by comparing a recently reported sRTP compound... Read More about Balanced Energy Gaps as a Key Design Rule for Solution‐Phase Organic Room Temperature Phosphorescence.

Conformational, Host, and Vibrational Effects Giving Rise to Dynamic TADF Behavior in the Through-Space Charge Transfer, Triptycene Bridged Acridine-Triazine Donor Acceptor TADF Molecule TpAT-tFFO (2023)
Journal Article
Miranda-Salinas, H., Rodriguez-Serrano, A., Kaminski, J. M., Dinkelbach, F., Hiromichi, N., Kusakabe, Y., …Monkman, A. P. (2023). Conformational, Host, and Vibrational Effects Giving Rise to Dynamic TADF Behavior in the Through-Space Charge Transfer, Triptycene Bridged Acridine-Triazine Donor Acceptor TADF Molecule TpAT-tFFO. Journal of Physical Chemistry C, 127(18), 8607-8617. https://doi.org/10.1021/acs.jpcc.2c07529

We present a joint experimental and theoretical study of the through-space charge transfer (CT) TADF molecule TpAT-tFFO. The measured fluorescence has a singular Gaussian line shape but two decay components, coming from two distinct molecular CT conf... Read More about Conformational, Host, and Vibrational Effects Giving Rise to Dynamic TADF Behavior in the Through-Space Charge Transfer, Triptycene Bridged Acridine-Triazine Donor Acceptor TADF Molecule TpAT-tFFO.

Oxidation State Tuning of Room Temperature Phosphorescence and Delayed Fluorescence in Phenothiazine and Phenothiazine‐5,5‐dioxide Dimers (2023)
Journal Article
Wright, I. A., Etherington, M. K., Batsanov, A. S., Monkman, A. P., & Bryce, M. R. (2023). Oxidation State Tuning of Room Temperature Phosphorescence and Delayed Fluorescence in Phenothiazine and Phenothiazine‐5,5‐dioxide Dimers. Chemistry - A European Journal, 29(30), Article e202300428. https://doi.org/10.1002/chem.202300428

Heterocyclic dimers consisting of combinations of butterfly-shaped phenothiazine (PTZ) and its chemically oxidized form phenothiazine-5,5-dioxide (PTZ(SO2)) have been synthesized. A twist is imposed across the dimers by ortho-substituents including m... Read More about Oxidation State Tuning of Room Temperature Phosphorescence and Delayed Fluorescence in Phenothiazine and Phenothiazine‐5,5‐dioxide Dimers.

Unexpected Quasi‐Axial Conformer in Thermally Activated Delayed Fluorescence DMAC‐TRZ, Pushing Green OLEDs to Blue (2023)
Journal Article
Stavrou, K., Franca, L. G., Böhmer, T., Duben, L. M., Marian, C. M., & Monkman, A. P. (2023). Unexpected Quasi‐Axial Conformer in Thermally Activated Delayed Fluorescence DMAC‐TRZ, Pushing Green OLEDs to Blue. Advanced Functional Materials, 33(25), Article 2300910. https://doi.org/10.1002/adfm.202300910

Hidden photophysics is elucidated in the very well-known thermally activated delayed fluorescence (TADF) emitter, DMAC-TRZ. A molecule that, based on its structure, is considered not to have more than one structural conformation. However, based on ex... Read More about Unexpected Quasi‐Axial Conformer in Thermally Activated Delayed Fluorescence DMAC‐TRZ, Pushing Green OLEDs to Blue.

Donor, Acceptor, and Molecular Charge Transfer Emission All in One Molecule (2023)
Journal Article
Franca, L. G., Danos, A., & Monkman, A. (2023). Donor, Acceptor, and Molecular Charge Transfer Emission All in One Molecule. Journal of Physical Chemistry Letters, 14(11), 2764-2771. https://doi.org/10.1021/acs.jpclett.2c03925

The molecular photophysics in the thermally activated delayed fluorescence (TADF) spiro-acridine–anthracenone compound, ACRSA, is dominated by the rigid orthogonal spirocarbon bridging bond between the donor and acceptor. This critically decouples th... Read More about Donor, Acceptor, and Molecular Charge Transfer Emission All in One Molecule.

Rupturing aromaticity by periphery overcrowding (2023)
Journal Article
Saha, P. K., Mallick, A., Turley, A. T., Bismillah, A. N., Danos, A., Monkman, A. P., …McGonigal, P. R. (2023). Rupturing aromaticity by periphery overcrowding. Nature Chemistry, 15(4), 516-525. https://doi.org/10.1038/s41557-023-01149-6

The balance between strain relief and aromatic stabilization dictates the form and function of non-planar π-aromatics. Overcrowded systems are known to undergo geometric deformations, but the energetically favourable π-electron delocalization of thei... Read More about Rupturing aromaticity by periphery overcrowding.

TADF Invariant of Host Polarity and Ultralong Fluorescence Lifetimes in a Donor‐Acceptor Emitter Featuring a Hybrid Sulfone‐Triarylboron Acceptor (2023)
Journal Article
Urban, M., Marek‐Urban, P. H., Durka, K., Luliński, S., Pander, P., & Monkman, A. P. (2023). TADF Invariant of Host Polarity and Ultralong Fluorescence Lifetimes in a Donor‐Acceptor Emitter Featuring a Hybrid Sulfone‐Triarylboron Acceptor. Angewandte Chemie International Edition, 62(9), https://doi.org/10.1002/anie.202217530

10H-Dibenzo[b,e][1,4]thiaborinine 5,5-dioxide (SO2B)—a high triplet (T1=3.05 eV) strongly electron-accepting boracycle was successfully utilised in thermally activated delayed fluorescence (TADF) emitters PXZ-Dipp-SO2B and CZ-Dipp-SO2B. We demonstrat... Read More about TADF Invariant of Host Polarity and Ultralong Fluorescence Lifetimes in a Donor‐Acceptor Emitter Featuring a Hybrid Sulfone‐Triarylboron Acceptor.

Fine‐Tuning the Photophysics of Donor‐Acceptor (D‐A 3 ) Thermally Activated Delayed Fluorescence Emitters Using Isomerisation (2022)
Journal Article
L. dos Santos, P., de Sa Pereira, D., Eng, J., Ward, J. S., Bryce, M. R., Penfold, T. J., & Monkman, A. P. (2023). Fine‐Tuning the Photophysics of Donor‐Acceptor (D‐A 3 ) Thermally Activated Delayed Fluorescence Emitters Using Isomerisation. ChemPhotoChem, 7(2), Article e202200248. https://doi.org/10.1002/cptc.202200248

Here two D–A3 regioisomers, comprising three dibenzothiophene-S,S-dioxide acceptor units attached to a central triazatruxene core, are studied. Both molecules show thermally activated delayed fluorescence (TADF), however, the efficiency of the TADF m... Read More about Fine‐Tuning the Photophysics of Donor‐Acceptor (D‐A 3 ) Thermally Activated Delayed Fluorescence Emitters Using Isomerisation.

Rational Molecular Design Enables Efficient Blue TADF−OLEDs with Flexible Graphene Substrate (2022)
Journal Article
Sharif, P., Alemdar, E., Ozturk, S., Caylan, O., Haciefendioglu, T., Buke, G., …Oral, A. (2022). Rational Molecular Design Enables Efficient Blue TADF−OLEDs with Flexible Graphene Substrate. Advanced Functional Materials, 32(47), Article 2207324. https://doi.org/10.1002/adfm.202207324

Observation of thermally activated delayed fluorescence (TADF) in conjugated systems redefined the molecular design approach to realize highly efficient organic light emitting diodes (OLEDs) in the early 2010s. Enabling effective reverse intersystem... Read More about Rational Molecular Design Enables Efficient Blue TADF−OLEDs with Flexible Graphene Substrate.

Intramolecular Hydrogen Bonding in Thermally Activated Delayed Fluorescence Emitters: Is There Evidence Beyond Reasonable Doubt? (2022)
Journal Article
Hempe, M., Kukhta, N. A., Danos, A., Batsanov, A. S., Monkman, A. P., & Bryce, M. R. (2022). Intramolecular Hydrogen Bonding in Thermally Activated Delayed Fluorescence Emitters: Is There Evidence Beyond Reasonable Doubt?. Journal of Physical Chemistry Letters, 13(35), 8221-8227. https://doi.org/10.1021/acs.jpclett.2c00907

Intramolecular hydrogen bonding between donor and acceptor segments in thermally activated delayed fluorescence (TADF) materials is now frequently employed to─purportedly─rigidify the structure and improve the emission performance of these materials.... Read More about Intramolecular Hydrogen Bonding in Thermally Activated Delayed Fluorescence Emitters: Is There Evidence Beyond Reasonable Doubt?.