Donor-modified asymmetric N/B/O multi-resonance TADF emitters for high-performance deep-blue OLEDs with the BT.2020 color gamut.

Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials of polycyclic heteroaromatics are attractive narrowband emitters in wide-color-gamut organic light-emitting diodes (OLEDs). However, deep-blue MR-TADF emitters with CIE coordinates fulfilling the BT.2020 standard and high efficiency still remain a significant challenge.

Recent advances in liquid chromatography-tandem mass spectrometry for the detection of thyroid hormones and thyroglobulin in clinical samples: A review.

Thyroid hormones (THs), including triiodothyronine (T3), thyroxine (T4), and their metabolites, are essential for regulating development, growth, and energy metabolism. Thyroglobulin (Tg) produced by thyroid follicular cells acts as an essential substrate for TH synthesis. The combination of THs with Tg is a widely used serological laboratory test for thyroid function assessment.

Computational Screening Two-Dimensional Conjugated Microporous Polymer Applied in Perovskite Solar Cells.

A two-dimensional (2D) conjugated microporous polymer with a structure of 2D nanosheets has been synthesized. Theoretical calculations and experimental results reveal that the Fermi level of this 2D polymer aligns well with perovskite absorber, and its conduction band is high enough to block electron transport into the anode. This 2D polymer is used to modify the hole transport layer, significantly improving its photoelectric properties, including enhanced hole mobility, matched energy level, and reduced recombination.

Regional Functionalization Molecular Design Strategy: A Key to Enhancing the Efficiency of Multi-Resonance OLEDs.

Herein, we propose a regional functionalization molecular design strategy that enables independent control of distinct pivotal parameters through different molecule segments. Three novel multiple resonances thermally activated delayed fluorescence (MR-TADF) emitters A-BN, DA-BN, and A-DBN, have been successfully synthesized by integrating highly rigid and three-dimensional adamantane-containing spirofluorene units into the MR framework. These molecules form two distinctive functional parts: part 1 comprises a boron-nitrogen (BN)-MR framework with adjacent benzene and fluorene units forming a central luminescent core characterized by an exceptionally rigid planar geometry, allowing for narrow FWHM values; part 2 includes peripheral mesitylene, benzene, and adamantyl groups, creating a unique three-dimensional "umbrella-like" conformation to mitigate intermolecular interactions and suppress exciton annihilation.

Structure Engineering of Acridine Donor to Optimize Color Purity of Blue Thermally Activated Delayed Fluorescence Emitters.

9,9-Dimethyl-9,10-dihydroacridine (DMAC) is one of the most widely used electron donor for constructing high-performance thermally activated delayed fluorescence (TADF) emitters. However, DMAC-based emitters often suffer from the imperfect color purity, particularly in blue emitters, due to its strong electron-donating capability. To modulate donor strength, 2,7-F-Ph-DMAC and 2,7-CF-Ph-DMAC were designed by introducing the electron-withdrawing 2-fluorophenyl and 2-(trifluoromethyl)phenyl at the 2,7-positions of DMAC.

Cyano Decoration of π-Bridge to Boost Photoluminescence and Electroluminescence Quantum Yields of Triazine/Carbazole Based Blue TADF Emitter.

In general, a large donor-acceptor dihedral angle is required to guarantee sufficient frontier molecular orbitals separation for thermally activated delayed fluorescence (TADF) emitters, which is intrinsically unfavorable for the radiative transition. We present a molecular design method favoring both reverse intersystem crossing (RISC) and radiative transitions even at a moderate D-A angle. A blue TADF emitter TrzBuCz-CN was designed with triazine/tert-butylcarbazole as donor/acceptor and cyano (CN) incorporated on the phenylene bridge.

Enrichment of Aggregation-Induced Emission Aggregates Using Acoustic Streaming Tweezers in Microfluidics for Trace Human Serum Albumin Detection.

Aggregation-dependent brightness (ADB) indirectly limits the in vitro performance of a pure aggregation-induced emission (AIE) probe in many ways; thus, controlling the aggregation state of the AIE probe is helpful for detecting an object of interest. Many studies are focused on the molecule design of the AIE probes, while less efforts have been made for the control of the aggregation of the AIEs. Here, an acoustic streaming tweezer (AST) generated using a gigahertz bulk acoustic wave resonator was applied to manipulate the aggregation status of the AIE probe and further enhance their performance for human serum albumin (HSA) detection.

Elucidation of the binding mechanism of astragaloside IV derivative with human serum albumin and its cardiotoxicity in zebrafish embryos.

LS-102 is a new derivative of astragaloside IV (AGS IV) that has been shown to possess potentially significant cardioprotective effects. However, there are no reports concerning its interaction with human serum albumin (HSA) and toxicology in vertebrates. The present investigation was undertaken to characterize the interaction of AGS IV and LS-102 with HSA using equilibrium dialysis and UHPLC-MS/MS methods, along with computational methods.

Constructing Highly Efficient Blue OLEDs with External Quantum Efficiencies up to 7.5 % Based on Anthracene Derivatives.

Acquiring desirable device performance with deep-blue color purity that fulfills practical application requirements is still a challenge. Bipolar fluorescent emitters with hybrid local and charge transfer (HLCT) state may serve to address this issue. Herein, by inserting anthracene core in the deep-blue building blocks, the authors successfully developed two highly twisted D-π-A fluorescent emitters, ICz-An-PPI and IP-An-PPI, featuring different acceptor groups.

Rational Utilization of Intramolecular Hydrogen Bonds to Achieve Blue TADF with EQEs of Nearly 30% and Single Emissive Layer All-TADF WOLED.

A series of highly efficient blue thermally activated delayed fluorescence (TADF) compounds, SON-Cz, SON-BuCz, and SON-PhCz, were developed. Pyridinyl was introduced as the bridging unit between carbazole donors and sulfone acceptor. Intramolecular hydrogen bonds between the pyridine N atom and carbazole H atoms were detected in single crystals, which suppressed the twisting of carbazole rings and dramatically increased the molecular rigidity.

Highly Efficient Simple-Structure Sky-Blue Organic Light-Emitting Diode Using a Bicarbazole/Cyanopyridine Bipolar Host.

Up to now, the most efficient blue phosphorescent organic light-emitting diode (PhOLED) was achieved with a maximum external quantum efficiency (η) of 34.1% by using an exciplex cohost. It still remains a challenge to obtain such high efficiencies using a single-host matrix.

Effects of Electron Affinity and Steric Hindrance of the Trifluoromethyl Group on the π-Bridge in Designing Blue Thermally Activated Delayed Fluorescence Emitters.

To explore the correlation of the acceptor electron affinity and the molecular conformation to the thermally activated delayed fluorescence (TADF) feature, a series of d-π-A molecules were designed and synthesized with triazine (Trz) as the acceptor (A) and carbazole (Cz) or tert-butylcarbazole (BuCz) as the donor (D). On the phenylene bridge between D and A, methyl or trifluoromethyl was incorporated close either to D or to A to tune the molecular conformation and the electron-withdrawing ability of acceptor. Both the twist angles and the singlet and triplet energy difference (ΔE ) were observed strongly dependent on the type and position of the substituent on the π-bridge.

Detection and Discrimination of Volatile Organic Compounds using a Single Film Bulk Acoustic Wave Resonator with Temperature Modulation as a Multiparameter Virtual Sensor Array.

This paper describes the detection and discrimination of volatile organic compounds (VOCs) using an e-nose system based on a multiparameter virtual sensor array (VSA), which consists of a single-chip temperature-compensated film bulk acoustic wave resonator (TC-FBAR) coated with 20-bilayer self-assembled poly(sodium 4-styrenesulfonate)/poly(diallyldimethylammonium chloride) thin films. The high-frequency and microscale FBAR multiparameter VSA was realized by temperature modulation, which can greatly reduce the cost and complexity compared to those of a traditional e-nose system and can allow it to operate at different temperatures. The discrimination effect depends on the synergy of temperature modulation and the sensing material.

Efficient Deep-Blue Electrofluorescence with an External Quantum Efficiency Beyond 10.

The design of blue fluorescent materials combining both deep-blue emission (CIE<0.06) and high-efficiency climbing over the typically limited exciton production efficiency of 25% is a challenge for organic light-emitting diodes (OLEDs). In this work, we have synthesized two blue luminogens, trans-9,10-bis(2-butoxyphenyl)anthracene (BBPA) and trans-9,10-bis (2,4-dimethoxyphenyl)anthracene with high photoluminescence quantum yields (PLQYs) of 89.

Modulation of n-Type Units in Bipolar Host Materials toward High-Performance Phosphorescent OLEDs.

9'-Pyridinyl-9'H-9,3':6',9″-tercarbazole (PyCz) is a bipolar host material in phosphorescent organic light-emitting diodes (PhOLEDs). A second n-type unit, either pyridine or diphenylphosphine dioxide (DPPO), is introduced onto the pyridine ring of PyCz at para- or metasite to design and prepare four novel "dual n-type unit bipolar host" materials m-BPyCz, p-BPyCz, m-POPyCz, and p-POPyCz. The incorporation of the second n-type unit pulls down the lowest unoccupied molecular orbitals and facilitates electron injection and transportation, resulting in better charge-balancing ability.

Dual n-type units including pyridine and diphenylphosphine oxide: effective design strategy of host materials for high-performance organic light-emitting diodes.

By using pyridine and diphenylphosphine oxide (DPPO) as dual n-type units, two novel bipolar hosts, namely (5-(3,5-di(9-carbazol-9-yl)phenyl)pyridin-3-yl)diphenylphosphine oxide (-PyPOmCP), and (6-(3,5-di(9-carbazol-9-yl)phenyl)pyridin-3-yl)diphenylphosphine oxide (-PyPOmCP) are developed for blue and green phosphorescent organic light-emitting diodes (PhOLEDs). Direct linking of the dual n-type units not only pulls the LUMOs down, but also keeps the HOMO levels shallow, and leads to high triplet energies (2.78-2.

Simple Bipolar Host Materials for High-Efficiency Blue, Green, and White Phosphorescence OLEDs.

3-(1H-Pyrazol-1-yl)pyridine is used as electron-transporting unit to construct bipolar host materials o-CzPyPz, m-CzPyPz, and p-CzPyPz for application in phosphorescent organic light-emitting diodes (PhOLEDs). By varying the ortho-, meta-, or para-linking mode between the n-type 3-(1H-pyrazol-1-yl)pyridine and the p-type carbazole on phenylene bridge, the optoelectronic parameters are tuned to large extent. The highly twisted o-CzPyPz has high triplet energy of 2.

Cyanopyridine Based Bipolar Host Materials for Green Electrophosphorescence with Extremely Low Turn-On Voltages and High Power Efficiencies.

Low driving voltage and high power efficiency are basic requirements when practical applications of organic light emitting diodes (OLEDs) in displays and lighting are considered. Two novel host materials m-PyCNmCP and 3-PyCNmCP incorporating cyanopyridine moiety as electron-transporting unit are developed for use in fac-tris(2-phenylpyridine)iridium(III) (Ir(ppy)3) based green phosphorescent OLEDs (PhOLEDs). Extremely low turn-on voltages of 2.

Universal Host Materials for High-Efficiency Phosphorescent and Delayed-Fluorescence OLEDs.

A series of bipolar hosts, namely, 5-(2-(9H-carbazol-9-yl)-phenyl)-1,3-dipyrazolbenzene (o-CzDPz), 5-(3-(9H-carbazol-9-yl)-phenyl)-1,3-dipyrazolbenzene (m-CzDPz), 5-(9-phenyl-9H-carbazol-3-yl)-1,3-dipyrazolbenzene (3-CzDPz), and 5-(3,5-di(9H-carbazol-9-yl)-phenyl)-1,3-dipyrazolbenzene (mCPDPz), are developed for phosphorescent and thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). They are designed by selecting pyrazole as n-type unit and carbazole as p-type one. The triplet energy (E(T)), the frontier molecular orbital level, and charge transporting abilities, are adjusted by varying the molar ratio of pyrazole to carbazole and the linking mode between them.

Photostable Fluorophenyl-Substituted Cyclometalated Platinum(II) Emitters for Monitoring of Molecular Oxygen in Real Time.

The effects of fluorophenyl substituents on the photoluminescence, redox properties, and oxygen sensing behaviors of the cyclometalated Pt(II) complexes are reported. The Pt(II) complexes with fluorophenyl substituents at the para position on the phenyl ring of 2-phenylpyridine (ppy) exhibit higher oxygen sensitivities than those at the meta position. Photodegradation tests demonstrate that the introduction of fluorophenyl substituents can strongly improve the photostability of cyclometalated Pt(II) complexes.

Substituent effect on the photophysical properties, electrochemical properties and electroluminescence performance of orange-emitting iridium complexes.

A series of bis(2-phenylbenzothiozolato-N,C(2'))iridium(acetylacetonate) [(bt)(2)Ir(acac)] derivatives, 1-4, were synthesized. Different substituents (CF(3), F, CH(3), OCH(3)) were introduced in the benzothiazole ring to study the substituent effect on the photophysical, electrochemical properties and electroluminescent performance of the complexes, and finally to select high-performance phosphors for use in organic light-emitting diodes (OLEDs). All complexes 1-4 and (bt)(2)Ir(acac) are orange-emitting with tiny spectral difference, despite the variation of the substituent.

Pyrene-cored dendrimer with carbazole derivatives as dendrons: synthesis, properties and application in white light-emitting diode.

A new dendrimer using pyrene as core and carbazole derivative as dendron has been successfully prepared via Suzuki coupling reaction. Its chemical structure was confirmed through (1)H NMR, elemental analysis and MALDI-TOF MS methods. The dendrimer synthesized possessed excellent thermal stability with initial decomposition temperature over 470 °C and high fluorescence quantum yield of 86%.

Solution-processible thieno-[3,4-b]-pyrazine derivatives with large Stokes shifts for non-doped red light-emitting diodes.

A group of novel thieno-[3,4-b]-pyrazine-cored molecules containing polyphenyl dendrons with or without arylamino or carbazolyl surface groups (DTP, N-DTP and C-DTP) are synthesized and investigated. They are characterized by extra large Stokes shifts of over 250 nm. In addition, to provide the site-isolation effect on the planar emissive core, the bulky dendrons enable these molecules to be solution processible.