Highly efficient thermally activated delayed fluorescence (TADF) molecules are in urgent demand for solid‐state lighting and full‐color displays. Here, the design and synthesis of three ...triarylamine‐pyridine‐carbonitrile‐based TADF compounds, TPAPPC, TPAmPPC, and tTPAmPPC, are shown. They exhibit excellent photoluminescence quantum yields of 79−100% with small ΔEST values, fast reverse intersystem crossing (RISC), and high horizontal dipole ratios (Θ// = 86−88%) in the thin films leading to the enhancement of device light outcoupling. Consequently, a green organic light‐emitting diode (OLED) based on TPAmPPC shows a high average external quantum efficiency of 38.8 ± 0.6%, a current efficiency of 130.1 ± 2.1 cd A–1, and a power efficiency of 136.3 ± 2.2 lm W–1. The highest device efficiency of 39.8% appears to be record‐breaking among TADF‐based OLEDs to date. In addition, the TPAmPPC‐based device shows superior operation lifetime and high‐temperature resistance. It is worth noting that the TPA‐PPC‐based materials have excellent optical properties and the potential for making them strong candidates for TADF practical application.
Three 2,6‐diphenylpyridine‐3,5‐dicarbonitrile‐based compounds with excellent photoluminescent quantum yields (79–100%) and high horizontal dipole ratios (86−88%) in the thin films are demonstrated. With two methyl groups on the triarylamines, the spin−orbit coupling is enhanced due to the elevated locally excited triplet states (3LE), leading to a fast reverse intersystem crossing. Green thermally activated delayed fluorescence (TADF) organic light‐emitting diodes based on them exhibit a record‐high external quantum efficiency of 39.8% without any optical extraction technique.
Owing to the high technology maturity of thermally activated delayed fluorescence (TADF) emitter design with a specific molecular shape, extremely high-performance organic light-emitting diodes ...(OLEDs) have recently been achieved
via
various doping techniques. Recently, undoped OLEDs have drawn immense attention because of their manufacturing cost reduction and procedure simplification. However, capable materials as host emitters are rare and precious because general fluorophores in high-concentration states suffer from serious aggregation-caused quenching (ACQ) and undergo exciton quenching. In this work, a series of diboron materials, CzDBA, iCzDBA, and
t
BuCzDBA, is introduced to realize the effect of steric hindrance and the molecular aspect ratio
via
experimental and theoretical studies. We computed transition electric dipole moment (TEDM) and molecular dynamics (MD) simulations as a proof-of-concept model to investigate the molecular stacking in neat films. It is worth noting that the pure
t
BuCzDBA film with a high horizontal ratio of 92% is employed to achieve a nondoped OLED with an excellent external quantum efficiency of 26.9%. In addition, we demonstrated the first ultrathin emitting layer (1 nm) TADF device, which exhibited outstanding power efficiency. This molecular design and high-performance devices show the potential of power-saving and economical fabrication for advanced OLEDs.
A strategy of substituent engineering of DBA-based molecules is investigated
via
experimental and theoretical methods. A 1 nm-thick emitting layer OLED has been developed.
For the application of organic light-emitting diodes (OLEDs) in lighting and panels, the basic requirement is to include a full spectrum color range. Compared with the development of blue and green ...luminophores in thermally activated delayed fluorescence (TADF) technology, the progress of orange-to-red materials is slow and needs further investigation. In this study, three diboron compound-based materials, dPhADBA, dmAcDBA, and SpAcDBA, were designed and synthesized by nucleophilic arylation of three amine donors on 9,10-diboraanthracene (DBA) in a two-step reaction. With increasing electron-donating ability, they show orange-to-red emission with TADF characteristics. The electroluminescence of these diboron compounds exhibits emissions λmax at 613, 583, and 567 nm for dPhADBA, dmAcDBA, and SpAcDBA, respectively. It is noteworthy that the rod-like D-A-D structures can achieve high horizontal ratios (84–86%) and outstanding device performance for orange-to-red TADF OLEDs: the highest external quantum efficiencies for dPhADBA, dmAcDBA, and SpAcDBA are 11.1 ± 0.5, 24.9 ± 0.5, and 30.0 ± 0.8%, respectively. Therefore, these diboron-based molecules offer a promising avenue for the design of orange-to-red TADF emitters and the development of highly efficient orange-to-red OLEDs.
In contrast to the normal formation of cubic metal halide perovskite nanocrystals, CsPbCl3 cubes and edge-truncated cuboids have been synthesized by simply mixing CsCl, PbCl2, and sodium dodecyl ...sulfate (SDS) in dimethyl sulfoxide (DMSO) at room temperature and transferring a small volume of the mixture to toluene to form a precipitate. The tetragonal-phased CsPbCl3 cubes and some rectangular blocks have square and rectangular {100}/{001} faces, while the cuboids have additional {101}/{110} edges. Variation in the amount of PbCl2 transforms cubes to edge-truncated cuboids. Their absorption and emission band positions are nearly identical at 413–416 nm. Despite having relatively large sizes, the CsPbCl3 cubes and edge-truncated cuboids display photoluminescence quantum yields of 6.9 and 2.9%, respectively. Remarkably, adding didecyldimethylammonium chloride (DDAC) surfactant to the reaction mixture leads to a 2–4.6-fold enhancement in the emission intensity. It is envisioned that other cesium lead halide crystals of tunable shapes can be synthesized by using the green reaction conditions.
Role of lipid control in diabetic nephropathy Chen, Hung-Chun; Guh, Jinn-Yuh; Chang, Jer-Ming ...
Kidney international,
April 2005, 2005-04-00, 2005-Apr, 20050401, Volume:
67, Issue:
S94
Journal Article
Peer reviewed
Open access
Role of lipid control in diabetic nephropathy. Patients with diabetic nephropathy are known to be associated with many lipoprotein abnormalities, including higher plasma levels of very low-density ...lipoprotein, low-density lipoprotein and triglycerides, and lower levels of high-density lipoprotein. Many studies have reported that lipids may induce both glomerular and tubulointerstitial injury through mediators such as cytokines, reactive oxygen species, chemokines, and through hemodynamic changes. Clinical studies in patients with diabetic nephropathy showed that lipid control can be associated with an additional effect of reduction in proteinuria. Experimental studies demonstrated that lipid-lowering agents exerted a certain degree of renoprotection, through both indirect effects from lipid lowering and a direct effect on cell protection. Therefore, lipid control appears to be important in the prevention and treatment of diabetic nephropathy.
Diabetic nephropathy has become the leading cause of end-stage renal failure in many countries, including Taiwan. One of the major risk factors for the development and progression of diabetic nephropathy is dyslipidemia. In this paper we will review the role of lipid in mediating renal injury and the beneficial effects of lipid control in diabetic nephropathy.
Thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) have attracted public attention due to their high external quantum efficiency (EQE) and implication in future ...display technology. Despite their improved efficiency, TADF-based OLEDs still suffer from serious efficiency roll-off and short operational lifetimes. Herein, a diboron-based molecule, PhCzDBA, is designed and its device exhibits a maximum EQE (EQEmax) of 33.8% and only slight roll-off (EQEmax of 31.5% at 1000 cd m–2 and 28.8% at 3000 cd m–2). Furthermore, it shows superior stability among reported TADF devices (LT80 of 113 h at the initial luminance of 3000 cd m–2). Remarkably, its nondoped OLED shows a high EQEmax of 17.7% with a λmax > 580 nm, surpassing most orange nondoped OLEDs. Moreover, a decent white OLED device with an EQEmax of 16.4% and a color rendering index (CRI) of 73 can be achieved by incorporating a simple sandwich emitting layer configuration, exhibiting the potential and diverse applications in many aspects.
In recent years, the quest for achieving polycarbonates in a sustainable, atom economical, and green manner has achieved significant momentum. Much focus has been given to epoxide monomers that are ...derived from renewable feedstocks. Renewable feedstocks are attractive green alternatives to established petroleum-based materials for reducing the dependency of the polymer industry on fossil resources. Herein, we have employed a series of Co and Cr(salen)-based complexes as selective catalysts for the copolymerization of CO
2
and eugenol epoxide. We have observed that varying both diamine backbone as well as the substituents on the phenolate rings of the salen ligand, thereby altering the electron density around the metal center, has notable effects on the reactivity and selectivity of polymer formation. It was also observed that a decrease in CO
2
pressure led to the formation of cyclic carbonates. Thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) studies of the polymers reveal that these polymers are quite stable up to 250 C and have relatively high glass transition (
T
g
) temperatures (83 C). These findings present an easy strategy to prepare polycarbonates by using biobased eugenol monomers, and provide examples for potential sustainable polymer design and synthesis.
A series of Co(
iii
) and Cr(
iii
)(salen) complexes in the presence of onium salts have been examined for the coupling of CO
2
and biomass based eugenol epoxide for the selective production of polycarbonates in a partially sustainable process.
In recent years, the quest for achieving polycarbonates in a sustainable, atom economical, and green manner has achieved significant momentum. Much focus has been given to epoxide monomers that are ...derived from renewable feedstocks. Renewable feedstocks are attractive green alternatives to established petroleum-based materials for reducing the dependency of the polymer industry on fossil resources. Herein, we have employed a series of Co and Cr(salen)-based complexes as selective catalysts for the copolymerization of CO 2 and eugenol epoxide. We have observed that varying both diamine backbone as well as the substituents on the phenolate rings of the salen ligand, thereby altering the electron density around the metal center, has notable effects on the reactivity and selectivity of polymer formation. It was also observed that a decrease in CO 2 pressure led to the formation of cyclic carbonates. Thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) studies of the polymers reveal that these polymers are quite stable up to 250 °C and have relatively high glass transition ( T g ) temperatures (83 °C). These findings present an easy strategy to prepare polycarbonates by using biobased eugenol monomers, and provide examples for potential sustainable polymer design and synthesis.
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