An unusual plank-shaped nematogen with a graphene nanoribbon core (2019)
Journal Article
Farias, G., Simeão, D. S., Moreira, T. S., dos Santos, P. L., Bentaleb, A., Girotto, E., …Bechtold, I. H. (2019). An unusual plank-shaped nematogen with a graphene nanoribbon core. Journal of Materials Chemistry C Materials for optical and electronic devices, 7(39), 12080-12085. https://doi.org/10.1039/c9tc03704g

A [12]phenacene exclusively decorated with four lateral hexylester substituents self-assembles into a nematic liquid crystal glass on cooling after melting at high temperature. This uniaxial nematic organization of a plank-shaped nanographene is unpr... Read More about An unusual plank-shaped nematogen with a graphene nanoribbon core.

An optical and electrical study of full thermally activated delayed fluorescent white organic light emitting diodes (2017)
Journal Article
Pereira, D., Santos, P., Ward, J., Data, P., Okazaki, Y., Minakata, S., …Monkman, A. (2017). An optical and electrical study of full thermally activated delayed fluorescent white organic light emitting diodes. Scientific Reports, 7(1), Article 6234. https://doi.org/10.1038/s41598-017-06568-3

We report on the engineering of full thermally activated delayed fluorescence – based white organic light emitting diodes (W-OLEDs) composed of three emitters (2,7-bis(9,9-dimethyl-acridin-10-yl)-9,9-dimethylthioxanthene-S,S-dioxide (DDMA-TXO2), 2,7-... Read More about An optical and electrical study of full thermally activated delayed fluorescent white organic light emitting diodes.

Optical and Polarity Control of Donor–Acceptor Conformation and Their Charge-Transfer States in Thermally Activated Delayed-Fluorescence Molecules (2017)
Journal Article
dos Santos, P. L., Ward, J. S., Batsanov, A. S., Bryce, M. R., & Monkman, A. P. (2017). Optical and Polarity Control of Donor–Acceptor Conformation and Their Charge-Transfer States in Thermally Activated Delayed-Fluorescence Molecules. Journal of Physical Chemistry C, 121(30), 16462-16469. https://doi.org/10.1021/acs.jpcc.7b03672

This study reports two novel D–A–D molecules, 2,7-bis(phenothiazin-10-yl)-9,9-dimethylthioxanthene-S,S-dioxide (DPT-TXO2) and 2,7-bis(1-methylphenothiazin-10-yl)-9,9-dimethylthioxanthene-S,S-dioxide (DMePT-TXO2), where the latter differs by only a me... Read More about Optical and Polarity Control of Donor–Acceptor Conformation and Their Charge-Transfer States in Thermally Activated Delayed-Fluorescence Molecules.

The Contributions of Molecular Vibrations and Higher Triplet Levels to the Intersystem Crossing Mechanism in Metal-Free Organic Emitters (2017)
Journal Article
Huang, R., Avó, J., Northey, T., Chaning-Pearce, E., dos Santos, P. L., Ward, J. S., …Dias, F. B. (2017). The Contributions of Molecular Vibrations and Higher Triplet Levels to the Intersystem Crossing Mechanism in Metal-Free Organic Emitters. Journal of Materials Chemistry C Materials for optical and electronic devices, 5(25), 6269-6280. https://doi.org/10.1039/c7tc01958k

Intense, simultaneous, room temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) is observed in a series of donor-acceptor-donor (D–A–D) molecules. This dual-luminescence is stronger in the “angular” isomers, compared... Read More about The Contributions of Molecular Vibrations and Higher Triplet Levels to the Intersystem Crossing Mechanism in Metal-Free Organic Emitters.

Regio- and conformational isomerization critical to design of efficient thermally-activated delayed fluorescence emitters (2017)
Journal Article
Etherington, M. K., Franchello, F., Gibson, J., Northey, T., Santos, J., Ward, J. S., …Monkman, A. P. (2017). Regio- and conformational isomerization critical to design of efficient thermally-activated delayed fluorescence emitters. Nature Communications, 8, Article 14987. https://doi.org/10.1038/ncomms14987

Regio- and conformational isomerization are fundamental in chemistry, with profound effects upon physical properties, however their role in excited state properties is less developed. Here two regioisomers of bis(10H-phenothiazin-10-yl)dibenzo[b,d]th... Read More about Regio- and conformational isomerization critical to design of efficient thermally-activated delayed fluorescence emitters.

Indirect consequences of exciplex states on the phosphorescence lifetime of phenazine-based 1,2,3-triazole luminescent probes (2016)
Journal Article
Costa, B., Jardim, G., Santos, P., Calado, H., Monkman, A., Dias, F., …Cury, L. (2017). Indirect consequences of exciplex states on the phosphorescence lifetime of phenazine-based 1,2,3-triazole luminescent probes. Physical Chemistry Chemical Physics, 19(5), 3473-3479. https://doi.org/10.1039/c6cp06134f

The optical properties of phenazine derivative probe solutions involving intersystem crossing from singlet to triplet states were investigated by time resolved spectroscopy. The room temperature phosphorescence emission presented different time respo... Read More about Indirect consequences of exciplex states on the phosphorescence lifetime of phenazine-based 1,2,3-triazole luminescent probes.

Using Guest–Host Interactions To Optimize the Efficiency of TADF OLEDs (2016)
Journal Article
dos Santos, P. L., Ward, J. S., Bryce, M. R., & Monkman, A. P. (2016). Using Guest–Host Interactions To Optimize the Efficiency of TADF OLEDs. Journal of Physical Chemistry Letters, 2016(7), 3341-3346. https://doi.org/10.1021/acs.jpclett.6b01542

We show that the emitter and host combination must be optimized to minimize the reverse intersystem crossing (rISC) barrier and maximize thermally activated delayed fluorescence (TADF). The blue TADF emitter, 2,7-bis(9,9-dimethyl-acridin-10-yl)-9,9-d... Read More about Using Guest–Host Interactions To Optimize the Efficiency of TADF OLEDs.

Investigation of the Mechanisms Giving Rise to TADF in Exciplex States (2016)
Journal Article
dos Santos, P. L., Dias, F. B., & Monkman, A. P. (2016). Investigation of the Mechanisms Giving Rise to TADF in Exciplex States. Journal of Physical Chemistry C, 120(32), 18259-18267. https://doi.org/10.1021/acs.jpcc.6b05198

The donor–acceptor systems studied in this work have been demonstrated to show strong exciplex formation by their red-shifted PL emission when compared with the individual donor and acceptor molecules, and all give rise to delayed fluorescence. In al... Read More about Investigation of the Mechanisms Giving Rise to TADF in Exciplex States.

Engineering the singlet–triplet energy splitting in a TADF molecule (2016)
Journal Article
Santos, P. L., Ward, J. S., Data, P., Batsanov, A. S., Bryce, M. R., Dias, F. B., & Monkman, A. P. (2016). Engineering the singlet–triplet energy splitting in a TADF molecule. Journal of Materials Chemistry C Materials for optical and electronic devices, 4(17), 3815-3824. https://doi.org/10.1039/c5tc03849a

The key to engineering an efficient TADF emitter is to achieve a small energy splitting between a pair of molecular singlet and triplet states. This work makes important contributions towards achieving this goal. By studying the new TADF emitter 2,7-... Read More about Engineering the singlet–triplet energy splitting in a TADF molecule.

Spectroscopic studies of different poly3hexylthiophene chain environments in a polyfluorene matrix (2015)
Journal Article
Santos, P., Cury, L., Dias, F., & Monkman, A. (2016). Spectroscopic studies of different poly3hexylthiophene chain environments in a polyfluorene matrix. Journal of Luminescence, 172, 118-123. https://doi.org/10.1016/j.jlumin.2015.11.045

Optical properties of blends made of poly(9,9-dioctyl-fluorene-2,7-diyl) (PFO) and poly(3-hexylthiophene-2,5-diyl) (P3HT) were investigated and compared to those of poly(9,9-dioctylfluorene-alt-bithiophene) (F8T2) by steady state optical spectroscopy... Read More about Spectroscopic studies of different poly3hexylthiophene chain environments in a polyfluorene matrix.