Exact solution of kinetic analysis for thermally activated delayed fluorescence materials

Research at Kyushu, Kyoto and St Andrews Universities was supported by EPSRC and JSPS Core to Core grants (JSPS Core-to-core Program; EPSRC grant number EP/R035164/1). Authors are also grateful for financial support from the Program for Building Regional Innovation Ecosystems of the Ministry of Education, Culture, Sports, Science and Technology, Japan, JST ERATO Grant JPMJER1305, JSPS KAKENHI JP20H05840, and Kyulux Inc.The photophysical analysis of thermally activated delayed fluorescence (TADF) materials has become instrumental to providing insight into their stability and performance, which is not only relevant for organic light-emitting diodes (OLED), but also for other applications such as sensing, imaging and photocatalysis. Thus, a deeper understanding of the photophysics underpinning the TADF mechanism is required to push materials design further. Previously reported analyses in the literature of the kinetics of the various processes occurring in a TADF material rely on several a priori assumptions to estimate the rate constants for forward and reverse intersystem crossing (ISC and RISC, respectively). In this report, we demonstrate a method to determine these rate constants using a three-state model together with a steady-state approximation and, importantly, no additional assumptions. Further, we derive the exact rate equations, greatly facilitating a comparison of the TADF properties of structurally diverse emitters and providing a comprehensive understanding of the photophysics of these systems.PostprintPostprintPeer reviewe

Twisting of Porphyrin by Assembly in a Metal‐Organic Framework yielding Chiral Photoconducting Films for Circularly‐Polarized‐Light Detection

While materials based on organic molecules usually have either superior optoelectronic or superior chiral properties, the combination of both is scarce. Here, a crystalline chiroptical film based on porphyrin with homochiral side groups is presented. While the dissolved molecule has a planar, thus, achiral porphyrin core, upon assembly in a metal–organic framework (MOF) film, the porphyrin core is twisted and chiral. The close packing and the crystalline order of the porphyrin cores in the MOF film also results in excellent optoelectronic properties. By exciting the Soret band of porphyrin, efficient photoconduction with a high On-Off-ratio is realized. More important, handedness-dependent circularly-polarized-light photoconduction with a dissymmetry factor g of 4.3×10$^{−4}$ is obtained. We foresee the combination of such assembly-induced chirality with the rich porphyrin chemistry will enable a plethora of organic materials with exceptional chiral and optoelectronic properties

Molecular asymmetry and rigidification as strategies to activate and enhance thermally activated delayed fluorescence in deep-blue MR-TADF emitters

Funding; This work was supported financially by Kyulux Inc, JSPS Grant-in-Aid for Specially Promoted Research (23H05406), JST CREST (JPMJCR22B3), JSPS KAKENHI (23K20039), ESPRC (EP/R035164/1, EP/W007517/1), City University of Hong Kong (Project No. 9610637 and 9231531).Two novel deep-blue multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters, 1B-CzCrs and 2B-CzCrs, containing a fused carbazole unit were synthesized. The carbazole contributed to the emergence of TADF in these small molecules. Particularly, organic light-emitting diodes with 1B-CzCrs doped in the mCP host achieve a maximum external quantum efficiency of 12.8% at CIE coordinates of (0.146, 0.062).Peer reviewe

Genome-wide association study of semen volume, sperm concentration, testis size, and plasma inhibin B levels

Semen quality is affected by environmental factors, endocrine function abnormalities, and genetic factors. A GWAS recently identified ERBB4 at 2q34 as a genetic locus associated with sperm motility. However, GWASs for human semen volume and sperm concentration have not been conducted. In addition, testis size also reportedly correlates with semen quality, and it is important to identify genes that affect testis size. Reproductive hormones also play an important role in spermatogenesis. To date, genetic loci associated with plasma testosterone, sex hormone-binding globulin (SHBG), follicle stimulating hormone (FSH), and luteinizing hormone (LH) levels have been identified using GWASs. However, GWASs have not identified any relevant loci for plasma inhibin B levels. We conducted a two-stage GWAS using 811 Japanese men in a discovery stage followed by a replication stage using an additional 721 Japanese men. The results of the discovery and replication stages were combined into a meta-analysis. After setting a suggestive significance threshold for P values < 5 × 10-6　in the discovery stage, we identified ten regions with SNPs (semen volume: one, sperm concentration: three, testes size: two, and inhibin B: four). We selected only the most significant SNP in each region for replication genotyping. Combined discovery and replication results in the meta-analysis showed that the locus 12q21.31 associated with plasma inhibin B levels (rs11116724) had the most significant association (P = 5.7 × 10-8). The LRRIQ1 and TSPAN19 genes are located in the 12q21.31 region. This study provides new susceptibility variants that contribute to plasma inhibin B levels

Two boron atoms versus one : high-performance deep-blue multi-resonance thermally activated delayed fluorescence emitters

This work was supported financially by the JSPS Core-to-Core Program (grant number: JPJSCCA20180005) and Kyulux Inc. S. M. S. acknowledges support from the Marie Skłodowska-Curie Individual Fellowship (grant agreement No 838885 NarrowbandSSL). We would like to thank the Leverhulme Trust (RPG-2016-047) for financial support. E. Z.-C. is a Royal Society Leverhulme Trust Senior Research fellow (SRF\R1\201089). We thank the EPRSC for funding (EP/R035164/1). Computational resources have been provided by the Consortium des Équipements de Calcul Intensif (CÉCI), funded by the Fonds de la Recherche Scientifiques de Belgique (F. R. S.-FNRS) under Grant No. 2.5020.11, as well as the Tier-1 supercomputer of the Fédération Wallonie-Bruxelles, infrastructure funded by the Walloon Region under the grant agreement n1117545. Y. O. acknowledges funding by the Fonds de la Recherche Scientifique-FNRS under Grant no. F.4534.21 (MIS-IMAGINE). D. B. is a FNRS Research Director.Two new deep-blue narrowband multi-resonant emitters, 1B-DTACrs and 2B-DTACrs, one of which shows thermally activated delayed fluorescence (TADF), based on boron, nitrogen, and oxygen doped nanographenes are reported. Devices based on 2B-DTACrs showed an EQEmax of 14.8% and CIE coordinates of (0.150, 0.044), which are very close to the BT.2020 requirement for blue pixels.Publisher PDFPeer reviewe

Metapolitics – What is It?

What is metapolitics? This is the question which calls to account another one, more fundamental: what is ‘politics’? Politics is that what is missing. General politisation on phenomenal-media level overcasts the fact that there is no real politics at all! This article has emerged as a consequence of the author’s reading of a book Proces zapadu (A Trial to the West) by Croatian philosopher Mario Kopić, with indicative subtitle Metapolitical Essays, and tries to follow that very direction. His book belongs to rare, therefore more precious efforts in our close environment - of »re-thinking« politics. According to him, metapolitical way of approaching mat terms is emphasized today by reflecting the development of Western society at the break of a new millennium. Slavoj Žižek is detecting the place of metapolitics. He finds it in a framework of so called Marxist (i.e. utopian-socialist) paradigm. Therefore, political conflict is completely uncovered. But, unfortunately, just as a theatre of shadows, where the events are played which real place is on the Other scene (the one of economical processes). According to Dean Komel, metapolitics is that which follows from metaphysics as culture of philosophy, in transgressing into philosophy of culture. Finally, A Trial to the West must end with a call for its roots: culture and philosophy. That is possible with a help of metapolitics. This metapolitics is a code-name for metaphysics. The world we live in, according the author of the article, is not a physical phenomenon, cause then it would be unbearable. It is metaphysical, if it has a sense at all, and if the human is transgressive being, who longs for justice, truth and freedom

Two boron atoms versus one: high-performance deep-blue multi-resonance thermally activated delayed fluorescence emitters.

peer reviewedTwo new deep-blue narrowband multi-resonant emitters, 1B-DTACrs and 2B-DTACrs, one of which shows thermally activated delayed fluorescence (TADF), based on boron, nitrogen, and oxygen doped nanographenes are reported. Devices based on 2B-DTACrs showed an EQEmax of 14.8% and CIE coordinates of (0.150, 0.044), which are very close to the BT.2020 requirement for blue pixels