All Outputs (271)

Thermally Activated Delayed Fluorescence: Polarity, Rigidity, and Disorder in Condensed Phases (2022)
Journal Article
Phan Huu, D. A., Saseendran, S., Dhali, R., Gomes Franca, L., Stavrou, K., Monkman, A., & Painelli, A. (2022). Thermally Activated Delayed Fluorescence: Polarity, Rigidity, and Disorder in Condensed Phases. Journal of the American Chemical Society, 144(33), 15211 - 15222. https://doi.org/10.1021/jacs.2c05537

We present a detailed and comprehensive picture of the photophysics of thermally activated delayed fluorescence (TADF). The approach relies on a few-state model, parametrized ab initio on a prototypical TADF dye, that explicitly accounts for the nona... Read More about Thermally Activated Delayed Fluorescence: Polarity, Rigidity, and Disorder in Condensed Phases.

Laplace Transform Fitting as a Tool To Uncover Distributions of Reverse Intersystem Crossing Rates in TADF Systems (2022)
Journal Article
Kelly, D., Gomes Franca, L., Stavrou, K., Danos, A., & Monkman, A. P. (2022). Laplace Transform Fitting as a Tool To Uncover Distributions of Reverse Intersystem Crossing Rates in TADF Systems. Journal of Physical Chemistry Letters, 13(30), 6981-6986. https://doi.org/10.1021/acs.jpclett.2c01864

Donor–acceptor (D–A) thermally activated delayed fluorescence (TADF) molecules are exquisitely sensitive to D–A dihedral angle. Although commonly simplified to an average value, these D–A angles nonetheless exist as distributions across the individua... Read More about Laplace Transform Fitting as a Tool To Uncover Distributions of Reverse Intersystem Crossing Rates in TADF Systems.

Novel D–A chromophores with condensed 1,2,4-triazine system simultaneously display thermally activated delayed fluorescence and crystallization-induced phosphorescence (2022)
Journal Article
Maggiore, A., Tan, X., Brosseau, A., Danos, A., Miomandre, F., Monkman, A. P., …Clavier, G. (2022). Novel D–A chromophores with condensed 1,2,4-triazine system simultaneously display thermally activated delayed fluorescence and crystallization-induced phosphorescence. Physical Chemistry Chemical Physics, 24(29), 17770-17781. https://doi.org/10.1039/d2cp00777k

Control of photophysical properties is crucial for the continued development of electroluminescent devices and luminescent materials. Preparation and study of original molecules uncovers design rules towards efficient materials and devices. Here we h... Read More about Novel D–A chromophores with condensed 1,2,4-triazine system simultaneously display thermally activated delayed fluorescence and crystallization-induced phosphorescence.

Delayed Fluorescence by Triplet–Triplet Annihilation from Columnar Liquid Crystal Films (2022)
Journal Article
Gomes Franca, L., dos Santos, P. L., Pander, P., Cabral, M. G., Cristiano, R., Cazati, T., …Eccher, J. (2022). Delayed Fluorescence by Triplet–Triplet Annihilation from Columnar Liquid Crystal Films. ACS Applied Electronic Materials, 4(7), https://doi.org/10.1021/acsaelm.2c00432

Delayed fluorescence (DF) by triplet–triplet annihilation (TTA) is observed in solutions of a benzoperylene-imidoester mesogen that shows a hexagonal columnar mesophase at room temperature in the neat state. A similar benzoperylene-imide with a sligh... Read More about Delayed Fluorescence by Triplet–Triplet Annihilation from Columnar Liquid Crystal Films.

Emission and Absorption Tuning in TADF B,N‐Doped Heptacenes: Toward Ideal‐Blue Hyperfluorescent OLEDs (2022)
Journal Article
Stavrou, K., Madayanad Suresh, S., Hall, D., Danos, A., Kukhta, N. A., Slawin, A. M., …Zysman‐Colman, E. (2022). Emission and Absorption Tuning in TADF B,N‐Doped Heptacenes: Toward Ideal‐Blue Hyperfluorescent OLEDs. Advanced Optical Materials, 10(17), Article 2200688. https://doi.org/10.1002/adom.202200688

Developing high-efficiency purely organic blue organic light-emitting diodes (OLEDs) that meet the stringent industry standards is a major current research challenge. Hyperfluorescent device approaches achieve in large measure the desired high perfor... Read More about Emission and Absorption Tuning in TADF B,N‐Doped Heptacenes: Toward Ideal‐Blue Hyperfluorescent OLEDs.

Vibronic effects accelerate the intersystem crossing processes of the through-space charge transfer states in the triptycene bridged acridine–triazine donor–acceptor molecule TpAT-tFFO (2022)
Journal Article
Kaminski, J. M., Rodríguez-Serrano, A., Dinkelbach, F., Miranda-Salinas, H., Monkman, A. P., & Marian, C. M. (2022). Vibronic effects accelerate the intersystem crossing processes of the through-space charge transfer states in the triptycene bridged acridine–triazine donor–acceptor molecule TpAT-tFFO. Chemical Science, 13(23), https://doi.org/10.1039/d1sc07101g

Quantum chemical studies employing combined density functional and multireference configuration interaction methods suggest five excited electronic states to be involved in the prompt and delayed fluorescence emission of TpAT-tFFO. Three of them, a p... Read More about Vibronic effects accelerate the intersystem crossing processes of the through-space charge transfer states in the triptycene bridged acridine–triazine donor–acceptor molecule TpAT-tFFO.

Effects of donor position and multiple charge transfer pathways in asymmetric pyridyl-sulfonyl TADF emitters (2022)
Journal Article
Haykir, G., Aydemir, M., Tekin, A., Tekin, E., Danos, A., Yuksel, F., …Turksoy, F. (2022). Effects of donor position and multiple charge transfer pathways in asymmetric pyridyl-sulfonyl TADF emitters. Materials Today Communications, 31, Article 103550. https://doi.org/10.1016/j.mtcomm.2022.103550

We have designed and synthesized a pair of highly asymmetric D-aA-D′ type pyridyl-sulfonyl based isomers comprising phenothiazine (PTZ) and carbazole (Cz) donor units, which are able to emit thermally activated delayed fluorescence. PTZ-pS4-Py-2Cz an... Read More about Effects of donor position and multiple charge transfer pathways in asymmetric pyridyl-sulfonyl TADF emitters.

Extended Conjugation Attenuates the Quenching of Aggregation-Induced Emitters by Photocyclization Pathways (2022)
Journal Article
Turley, A., Saha, P., Danos, A., Bismillah, A., Monkman, A., Yufit, D., …McGonigal, P. (2022). Extended Conjugation Attenuates the Quenching of Aggregation-Induced Emitters by Photocyclization Pathways. Angewandte Chemie International Edition, 61(24), Article e202202193. https://doi.org/10.1002/anie.202202193

Herein, we expose how the antagonistic relationship between solid-state luminescence and photocyclization of oligoaryl alkenes chromophores is modulated by the conjugation length of their alkenyl backbones. Heptaaryl cycloheptatriene molecular rotors... Read More about Extended Conjugation Attenuates the Quenching of Aggregation-Induced Emitters by Photocyclization Pathways.

Dominant dimer emission provides colour stability for red thermally activated delayed fluorescence emitter (2022)
Journal Article
Cardeynaels, T., Etherington, M. K., Paredis, S., Batsanov, A. S., Deckers, J., Stavrou, K., …Maes, W. (2022). Dominant dimer emission provides colour stability for red thermally activated delayed fluorescence emitter. Journal of Materials Chemistry C Materials for optical and electronic devices, 10(15), https://doi.org/10.1039/d1tc04913e

Colour purity and stability in multi-donor thermally activated delayed fluorescence (TADF) emitters has significant implications for commercial organic light-emitting diode (OLED) design. The formation of emissive dimer states in the well-known 1,2,3... Read More about Dominant dimer emission provides colour stability for red thermally activated delayed fluorescence emitter.

The Effect of Imide Substituents on the Excited State Properties of Perylene Diimide Derivatives (2022)
Journal Article
Aksoy, E., Danos, A., Li, C., Monkman, A., & Varlikli, C. (2022). The Effect of Imide Substituents on the Excited State Properties of Perylene Diimide Derivatives. Turkish journal of science and technology, 17(1), 11-21. https://doi.org/10.55525/tjst.952823

Solid state optical properties of fluorescent materials are important for many photonic devices such as organic light emitting diodes, frequency down-converters or luminescent solar concentrators. Perylene diimides (PDIs) represent one of the most po... Read More about The Effect of Imide Substituents on the Excited State Properties of Perylene Diimide Derivatives.

Determining non-radiative decay rates in TADF compounds using coupled transient and steady state optical data (2022)
Journal Article
Sem, S., Jenatsch, S., Stavrou, K., Danos, A., Monkman, A. P., & Ruhstaller, B. (2022). Determining non-radiative decay rates in TADF compounds using coupled transient and steady state optical data. Journal of Materials Chemistry C Materials for optical and electronic devices, 10(12), 4878-4885. https://doi.org/10.1039/d1tc05594a

Thermally-activated delayed fluorescence (TADF) compounds are promising materials used in emissive layers of organic light-emitting diodes (OLEDs). Their main benefit is that they allow the internal quantum efficiency of the OLED to reach up to 100%... Read More about Determining non-radiative decay rates in TADF compounds using coupled transient and steady state optical data.

Diindolocarbazole – achieving multiresonant thermally activated delayed fluorescence without the need for acceptor units (2022)
Journal Article
Hall, D., Stavrou, K., Duda, E., Danos, A., Bagnich, S., Warriner, S., …Zysman-Colman, E. (2022). Diindolocarbazole – achieving multiresonant thermally activated delayed fluorescence without the need for acceptor units. Materials Horizons, 9(3), 1068-1080. https://doi.org/10.1039/d1mh01383a

In this work we present a new multi-resonance thermally activated delayed fluorescence (MR-TADF) emitter paradigm, demonstrating that the structure need not require the presence of acceptor atoms. Based on an in silico design, the compound DiICzMes4... Read More about Diindolocarbazole – achieving multiresonant thermally activated delayed fluorescence without the need for acceptor units.

Bridge control of photophysical properties in benzothiazole-phenoxazine emitters – from thermally activated delayed fluorescence to room temperature phosphorescence (2022)
Journal Article
Paredis, S., Cardeynaels, T., Deckers, J., Danos, A., Vanderzande, D., Monkman, A. P., …Maes, W. (2022). Bridge control of photophysical properties in benzothiazole-phenoxazine emitters – from thermally activated delayed fluorescence to room temperature phosphorescence. Journal of Materials Chemistry C Materials for optical and electronic devices, 10(12), 4775-4784. https://doi.org/10.1039/d1tc04885f

The bridging phenyl group in a fluorescent phenoxazine-benzothiazole donor–acceptor dyad is replaced by either a naphthalene or a thiophene moiety to probe the influence of a more extended conjugated system or the presence of a sulfur-containing hete... Read More about Bridge control of photophysical properties in benzothiazole-phenoxazine emitters – from thermally activated delayed fluorescence to room temperature phosphorescence.

Spiro donor–acceptor TADF emitters: naked TADF free from inhomogeneity caused by donor acceptor bridge bond disorder. Fast rISC and invariant photophysics in solid state hosts (2022)
Journal Article
Gomes Franca, L., Danos, A., & Monkman, A. (2022). Spiro donor–acceptor TADF emitters: naked TADF free from inhomogeneity caused by donor acceptor bridge bond disorder. Fast rISC and invariant photophysics in solid state hosts. Journal of Materials Chemistry C Materials for optical and electronic devices, 10(4), 1313-1325. https://doi.org/10.1039/d1tc04484b

We have studied the thermally activated delayed fluorescence (TADF) properties of the spiro-bridged donor–acceptor molecule, 10-phenyl-10H,10′H-spiro[acridine-9,9-anthracen]-10′-one, (ACRSA) in guest–host films and used it as a probe to explore the d... Read More about Spiro donor–acceptor TADF emitters: naked TADF free from inhomogeneity caused by donor acceptor bridge bond disorder. Fast rISC and invariant photophysics in solid state hosts.

Halogenation of a twisted non-polar π-system as a tool to modulate phosphorescence at room temperature (2021)
Journal Article
Farias, G., Salla, C. A., Aydemir, M., Sturm, L., Dechambenoit, P., Durola, F., …Bechtold, I. H. (2021). Halogenation of a twisted non-polar π-system as a tool to modulate phosphorescence at room temperature. Chemical Science, 12(45), https://doi.org/10.1039/d1sc04936d

Halogenation of a twisted three-fold symmetric hydrocarbon with F, Cl or Br leads to strong modulation of triplet–triplet annihilation and dual phosphorescence, one thermally activated and the other very persistent and visible by eye, with different... Read More about Halogenation of a twisted non-polar π-system as a tool to modulate phosphorescence at room temperature.

Why Do We Still Need a Stable Long Lifetime Deep Blue OLED Emitter? (2021)
Journal Article
Monkman, A. (2022). Why Do We Still Need a Stable Long Lifetime Deep Blue OLED Emitter?. ACS Applied Materials and Interfaces, 14(18), 20463-20467. https://doi.org/10.1021/acsami.1c09189

The need for a high efficiency deep blue organic emitter with narrow emission line width has never been so great. This is driven by the need to simplify the complex OLED stack for displays to enable larger substrate sizes to be used and greatly incre... Read More about Why Do We Still Need a Stable Long Lifetime Deep Blue OLED Emitter?.

Effects of asymmetric acceptor and donor positioning in deep blue pyridyl-sulfonyl based TADF emitters (2021)
Journal Article
Haykir, G., Aydemir, M., Danos, A., Gumus, S., Hizal, G., Monkman, A. P., & Turksoy, F. (2021). Effects of asymmetric acceptor and donor positioning in deep blue pyridyl-sulfonyl based TADF emitters. Dyes and Pigments, 194, Article 109579. https://doi.org/10.1016/j.dyepig.2021.109579

In this work, we report synthesis and photophysical properties of deep-blue emitting donor-acceptor (D-A) and donor-acceptor-donor (D-A-D) thermally activated delayed fluorescence (TADF) molecules, where the molecules designed using carbazole as a do... Read More about Effects of asymmetric acceptor and donor positioning in deep blue pyridyl-sulfonyl based TADF emitters.

Controlling through-space and through-bond intramolecular charge transfer in bridged D–D′–A TADF emitters (2021)
Journal Article
Miranda-Salinas, H., Hung, Y., Chen, Y., Luo, D., Kao, H., Chang, C., …Monkman, A. (2021). Controlling through-space and through-bond intramolecular charge transfer in bridged D–D′–A TADF emitters. Journal of Materials Chemistry C Materials for optical and electronic devices, 9(28), https://doi.org/10.1039/d1tc02316k

Donor–donor′–acceptor molecules where the donor′ bridges the donor and acceptor have different possible interaction pathways for charge transfer. Here we study a series of donor–donor′–acceptor molecules, having the same acceptor and donor′ but diffe... Read More about Controlling through-space and through-bond intramolecular charge transfer in bridged D–D′–A TADF emitters.

Silylethynyl Substitution for Preventing Aggregate Formation in Perylene Diimides (2021)
Journal Article
Aksoy, E., Danos, A., Li, C., Monkman, A. P., & Varlikli, C. (2021). Silylethynyl Substitution for Preventing Aggregate Formation in Perylene Diimides. Journal of Physical Chemistry C, 125(23), 13041-13049. https://doi.org/10.1021/acs.jpcc.1c03131

Ethynylene-bridged perylene diimides (PDIs) with different sized silane groups have been synthesized as a steric blocking group to prevent the formation of non-radiative trap sites, for example, strong H-aggregates and other dimers or excimers. Excit... Read More about Silylethynyl Substitution for Preventing Aggregate Formation in Perylene Diimides.

Vibrational Damping Reveals Vibronic Coupling in Thermally Activated Delayed Fluorescence Materials (2021)
Journal Article
Hempe, M., Kukhta, N. A., Danos, A., Fox, M. A., Batsanov, A. S., Monkman, A. P., & Bryce, M. R. (2021). Vibrational Damping Reveals Vibronic Coupling in Thermally Activated Delayed Fluorescence Materials. Chemistry of Materials, 33(9), 3066-3080. https://doi.org/10.1021/acs.chemmater.0c03783

We investigate a series of D–A molecules consisting of spiro[acridan-9,9′-fluorene] as the donor and 2-phenylenepyrimidine as the acceptor. In two of the materials, a spiro center effectively electronically isolates the D unit from (consequently) opt... Read More about Vibrational Damping Reveals Vibronic Coupling in Thermally Activated Delayed Fluorescence Materials.