Silica nanoparticles with thermally activated delayed fluorescence for live cell imaging (2019)
Journal Article
Crucho, C. I., Avó, J., Nobuyasu, R., N. Pinto, S., Fernandes, F., Lima, J. C., …Dias, F. B. (2020). Silica nanoparticles with thermally activated delayed fluorescence for live cell imaging. Materials Science and Engineering: C, 109, Article 110528. https://doi.org/10.1016/j.msec.2019.110528

Thermally activated delayed fluorescence (TADF) has revolutionized the field of organic light emitting diodes owing to the possibility of harvesting non-emissive triplet states and converting them in emissive singlet states. This mechanism generates... Read More about Silica nanoparticles with thermally activated delayed fluorescence for live cell imaging.

Balancing charge-transfer strength and triplet states for deep-blue thermally activated delayed fluorescence with an unconventional electron rich dibenzothiophene acceptor (2019)
Journal Article
Huang, R., Kukhta, N., Ward, J., Danos, A., Batsanov, A., Bryce, M., & Dias, F. (2019). Balancing charge-transfer strength and triplet states for deep-blue thermally activated delayed fluorescence with an unconventional electron rich dibenzothiophene acceptor. Journal of Materials Chemistry C Materials for optical and electronic devices, 7(42), 13224-13234. https://doi.org/10.1039/c9tc02175b

Manipulation of the emission properties of deep-blue emitters exhibiting thermally activated delayed fluorescence (TADF) through molecular design is challenging. We present an effective strategy to probe deeper into the role of localized (LE) and cha... Read More about Balancing charge-transfer strength and triplet states for deep-blue thermally activated delayed fluorescence with an unconventional electron rich dibenzothiophene acceptor.

Achieving Conformational Control in RTP and TADF Emitters by Functionalization of the Central Core (2019)
Journal Article
Kukhta, N., Huang, R., Batsanov, A., Bryce, M., & Dias, F. (2019). Achieving Conformational Control in RTP and TADF Emitters by Functionalization of the Central Core. Journal of Physical Chemistry C, 123(43), 26536-26546. https://doi.org/10.1021/acs.jpcc.9b08238

Three new symmetrical donor–acceptor–donor (D–A–D)-type molecules were prepared with phenothiazine (PTZ) as electron donors and 9,9-dimethylthioxanthene (TX) as the electron acceptor. The PTZ groups are attached at different positions on the acceptor... Read More about Achieving Conformational Control in RTP and TADF Emitters by Functionalization of the Central Core.

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 inelastic multislice simulation method incorporating plasmon energy losses (2019)
Journal Article
Mendis, B. (2019). An inelastic multislice simulation method incorporating plasmon energy losses. Ultramicroscopy, 206, Article 112816. https://doi.org/10.1016/j.ultramic.2019.112816

Quantitative electron microscopy requires accurate simulation methods that take into account both elastic and inelastic scattering of the high energy electrons within the specimen. Here a method to combine plasmon excitations, the dominant energy los... Read More about An inelastic multislice simulation method incorporating plasmon energy losses.

Molecular Design Strategies for Color Tuning of Blue TADF Emitters (2019)
Journal Article
Stachelek, P., Ward, J. S., dos Santos, P. L., Danos, A., Colella, M., Haase, N., …Monkman, A. P. (2019). Molecular Design Strategies for Color Tuning of Blue TADF Emitters. ACS Applied Materials and Interfaces, 11(30), 27125-27133. https://doi.org/10.1021/acsami.9b06364

New thermally activated delayed fluorescence (TADF) blue emitter molecules based on the known donor−acceptor−donor (D−A−D)- type TADF molecule, 2,7-bis(9,9-dimethylacridin-10-yl)-9,9-dimethylthioxanthene- S,S-dioxide (DDMA-TXO2), are reported. The mo... Read More about Molecular Design Strategies for Color Tuning of Blue TADF Emitters.

Revealing Resonance Effects and Intramolecular Dipole Interactions in the Positional Isomers of Benzonitrile-Core Thermally Activated Delayed Fluorescence Materials (2019)
Journal Article
Kukhta, N., Higginbotham, H., Matulaitis, T., Danos, A., Bismillah, A., Haase, N., …Monkman, A. (2019). Revealing Resonance Effects and Intramolecular Dipole Interactions in the Positional Isomers of Benzonitrile-Core Thermally Activated Delayed Fluorescence Materials. Journal of Materials Chemistry C Materials for optical and electronic devices, 7(30), 9184-9194. https://doi.org/10.1039/c9tc02742d

We report on the properties of the three positional isomers of (2,7-di-tert-butyl-9,9-dimethylacridin-10(9H)-yl)benzonitrile, which are found to have comparable donor steric environments and donor–acceptor dihedral angles. An unexpected intramolecula... Read More about Revealing Resonance Effects and Intramolecular Dipole Interactions in the Positional Isomers of Benzonitrile-Core Thermally Activated Delayed Fluorescence Materials.

Revising of the Purcell effect in periodic metal-dielectric structures: the role of absorption (2019)
Journal Article
Morozov, K. M., Ivanov, K. A., de Sa Pereira, D., Menelaou, C., Monkman, A. P., Pozina, G., & Kaliteevski, M. A. (2019). Revising of the Purcell effect in periodic metal-dielectric structures: the role of absorption. Scientific Reports, 9(1), Article 9604. https://doi.org/10.1038/s41598-019-46071-5

Periodic metal-dielectric structures attract substantial interest since it was previously proposed that the spontaneous emission amplification rates (the Purcell factor) in such structures can reach enormous values up to 105. However, the role of abs... Read More about Revising of the Purcell effect in periodic metal-dielectric structures: the role of absorption.

In-Operando X-ray diffraction imaging of thermal strains in fully packaged silicon devices (2019)
Journal Article
Tanner, B., Vijayaraghavan, R., Roarty, B., Danilewsky, A., & McNally, P. (2019). In-Operando X-ray diffraction imaging of thermal strains in fully packaged silicon devices. Microelectronics Reliability, 99, 232-238. https://doi.org/10.1016/j.microrel.2019.06.006

The application of X-ray Diffraction Imaging to measure in operando thermal strains at individually powered components within fully packaged LM3046 silicon devices is described. It is shown that as the local strains increase with power dissipated, ab... Read More about In-Operando X-ray diffraction imaging of thermal strains in fully packaged silicon devices.

Identifying the Factors That Lead to PLQY Enhancement in Diluted TADF Exciplexes Based on Carbazole Donors (2019)
Journal Article
Colella, M., Danos, A., & Monkman, A. P. (2019). Identifying the Factors That Lead to PLQY Enhancement in Diluted TADF Exciplexes Based on Carbazole Donors. Journal of Physical Chemistry C, 123(28), 17318-17324. https://doi.org/10.1021/acs.jpcc.9b03538

Here we compare the effects of solid-state dilution on the photophysical and electrical performance of three TADF exciplexes based on carbazole containing donors with a high-performance acceptor PO-T2T. We observe intrinsically different photophysica... Read More about Identifying the Factors That Lead to PLQY Enhancement in Diluted TADF Exciplexes Based on Carbazole Donors.

The influence of molecular geometry on the efficiency of thermally activated delayed fluorescence (2019)
Journal Article
Nobuyasu, R. S., Ward, J. S., Gibson, J., Laidlaw, B. A., Ren, Z., Data, P., …Dias, F. B. (2019). The influence of molecular geometry on the efficiency of thermally activated delayed fluorescence. Journal of Materials Chemistry C Materials for optical and electronic devices, 7(22), 6672-6684. https://doi.org/10.1039/c9tc00720b

In this work we successfully developed a strategy for positively influencing the conformation of thermally activated delayed fluorescence (TADF) molecules containing phenothiazine as the electron donor (D) unit, and dibenzothiophene-S,S-dioxide as th... Read More about The influence of molecular geometry on the efficiency of thermally activated delayed fluorescence.

Electroabsorption Spectroscopy as a Tool to Probe Charge-Transfer and State Mixing in Thermally-Activated Delayed Fluorescence Emitters (2019)
Journal Article
De Sa Pereira, D., Menelaou, C., Danos, A., Marian, C. M., & Monkman, A. P. (2019). Electroabsorption Spectroscopy as a Tool to Probe Charge-Transfer and State Mixing in Thermally-Activated Delayed Fluorescence Emitters. Journal of Physical Chemistry Letters, 10(12), 3205-3211. https://doi.org/10.1021/acs.jpclett.9b00999

Solid-state electroabsorption is demonstrated as a powerful tool to probe the charge-transfer (CT) character and state mixing in the low energy optical transitions of two structurally similar thermally-activated delayed fluorescent (TADF) materials w... Read More about Electroabsorption Spectroscopy as a Tool to Probe Charge-Transfer and State Mixing in Thermally-Activated Delayed Fluorescence Emitters.

Delayed Blue Fluorescence via Upper-triplet State Crossing from C-C Bonded Donor-Acceptor Charge-Transfer Molecules with Azatriangulene cores (2019)
Journal Article
Ward, J., Kukhta, N., Dos Santos, P., Congrave, D., Batsanov, A., Monkman, A., & Bryce, M. (2019). Delayed Blue Fluorescence via Upper-triplet State Crossing from C-C Bonded Donor-Acceptor Charge-Transfer Molecules with Azatriangulene cores. Chemistry of Materials, 31(17), 6684-6695. https://doi.org/10.1021/acs.chemmater.9b01184

We report the synthesis and structural and photophysical characterization of two series of molecules with functionalized azatriangulene electron donor cores and three pendant electron acceptor units. The presented donor and acceptor units are joined... Read More about Delayed Blue Fluorescence via Upper-triplet State Crossing from C-C Bonded Donor-Acceptor Charge-Transfer Molecules with Azatriangulene cores.

Planck's generalised radiation law and its implications for cathodoluminescence spectra (2019)
Journal Article
Mendis, B. (2019). Planck's generalised radiation law and its implications for cathodoluminescence spectra. Ultramicroscopy, 204, 73-80. https://doi.org/10.1016/j.ultramic.2019.05.007

Cathodoluminescence (CL) is an important analytical technique for probing the optical properties of materials at high spatial resolution. Interpretation of CL spectra is however complicated by the fact that the spectrum depends on the carrier injecti... Read More about Planck's generalised radiation law and its implications for cathodoluminescence spectra.

Understanding the role of selenium in defect passivation for highly efficient selenium-alloyed cadmium telluride solar cells (2019)
Journal Article
Fiducia, T. A., Mendis, B. G., Li, K., Grovenor, C. R., Munshi, A. H., Barth, K., …Walls, J. M. (2019). Understanding the role of selenium in defect passivation for highly efficient selenium-alloyed cadmium telluride solar cells. Nature Energy, 4, 504-511. https://doi.org/10.1038/s41560-019-0389-z

Electricity produced by cadmium telluride (CdTe) photovoltaic modules is the lowest-cost electricity in the solar industry, and now undercuts fossil fuel-based sources in many regions of the world. This is due to recent efficiency gains brought about... Read More about Understanding the role of selenium in defect passivation for highly efficient selenium-alloyed cadmium telluride solar cells.

Controlling the growth of single crystal ZnO nanowires by tuning the atomic layer deposition parameters of the ZnO seed layer (2019)
Journal Article
Galan-Gonzalez, A., Gallant, A., Zeze, D. A., & Atkinson, D. (2019). Controlling the growth of single crystal ZnO nanowires by tuning the atomic layer deposition parameters of the ZnO seed layer. Nanotechnology, 30(30), Article 305602. https://doi.org/10.1088/1361-6528/ab186a

Semiconducting nanowires (NWs) offer exciting prospects for a wide range of technological applications. The translation of NW science into technology requires reliable high quality large volume production. This study provides an in-depth investigatio... Read More about Controlling the growth of single crystal ZnO nanowires by tuning the atomic layer deposition parameters of the ZnO seed layer.

Intramolecular Dimerization Quenching of Delayed Emission in Asymmetric D-D’-A TADF Emitters (2019)
Journal Article
Woon, K. L., Yi, C., Pan, K., Etherington, M. K., Wu, C., Wong, K., & Monkman, A. P. (2019). Intramolecular Dimerization Quenching of Delayed Emission in Asymmetric D-D’-A TADF Emitters. Journal of Physical Chemistry C, 123(19), 12400-12410. https://doi.org/10.1021/acs.jpcc.9b01900

Understanding the excited-state dynamics and conformational relaxation in thermallyactivated delayed fluorescence (TADF) molecules, including conformations that potentially support intramolecular through-space charge transfer, can open new avenues fo... Read More about Intramolecular Dimerization Quenching of Delayed Emission in Asymmetric D-D’-A TADF Emitters.

Fully depleted emitter layers: a novel method to improve band alignment in thin-film solar cells (2019)
Journal Article
Mendis, B. (2019). Fully depleted emitter layers: a novel method to improve band alignment in thin-film solar cells. Semiconductor Science and Technology, 34(5), Article 055008. https://doi.org/10.1088/1361-6641/ab0c2b

The interface between the emitter and absorber layers in a thin-film solar cell must satisfy two important criteria, namely a small lattice mismatch and electron barrier height. It is shown that the barrier height is lowered when the emitter is fully... Read More about Fully depleted emitter layers: a novel method to improve band alignment in thin-film solar cells.

Persistent Dimer Emission in Thermally Activated Delayed Fluorescence Materials (2019)
Journal Article
Etherington, M. K., Kukhta, N. A., Higginbotham, H. F., Danos, A., Bismillah, A. N., Graves, D. R., …Monkman, A. P. (2019). Persistent Dimer Emission in Thermally Activated Delayed Fluorescence Materials. Journal of Physical Chemistry C, 123(17), 11109-11117. https://doi.org/10.1021/acs.jpcc.9b01458

We expose significant changes in emission color of carbazole-based thermally activated delayed fluorescence (TADF) emitters that arise through the presence of persistent dimer states in thin films and organic light-emitting diodes(OLEDs). Direct phot... Read More about Persistent Dimer Emission in Thermally Activated Delayed Fluorescence Materials.

Impact of Methoxy Substituents on Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence in All-Organic Donor–Acceptor Systems (2019)
Journal Article
Ward, J. S., Nobuyasu, R. S., Fox, M. A., Aguilar, J. A., Hall, D., Batsanov, A. S., …Bryce, M. R. (2019). Impact of Methoxy Substituents on Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence in All-Organic Donor–Acceptor Systems. Journal of Organic Chemistry, 84(7), 3801-3816. https://doi.org/10.1021/acs.joc.8b02848

Thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) are known to occur in organic D–A–D and D–A systems where the donor group contains the phenothiazine unit and the acceptor is dibenzothiophene-S,S-dioxide. Thi... Read More about Impact of Methoxy Substituents on Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence in All-Organic Donor–Acceptor Systems.