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Triplet‐triplet fusion (TTF) can effectively transfer triplet excitons to singlet energy level and exhibit good stability, making it widely used in blue fluorescence organic light emitting diodes (OLEDs) for practical application. However, the efficiency of the resulting blue fluorescence OLEDs is still fundamentally limited. Herein, this work introduces a hot exciton efficiency enhancement layer (EEL) between TTF emissive layer and electron‐transporting layer for the first time. It can be found that the triplet excitons are greatly utilized by the efficient hot exciton EEL. As a result, a high efficiency blue fluorescence OLED is successfully developed, exhibiting a maximum external quantum efficiency of 15.2% at the luminance of 4068.0 cd m−2, achieving a breakthrough in the efficiency of blue TTF‐OLEDs. Transient electroluminescence (TrEL) measurements and detailed theoretical calculations confirm the key role of the effective hot exciton process from the high‐lying triplet energy level (Tn, n ≥ 2) to S1 via a reverse intersystem crossing (hRISC). Furthermore, the device lifetime is also greatly improved owing to the fast and efficient hRISC in the introduced hot exciton EEL. This work has important guiding significance for constructing high efficiency blue fluorescence OLEDs by introducing hot exciton molecules. [ABSTRACT FROM AUTHOR]

The development of lasing materials with weak pile‐up effect from triplet excitons, low lasing threshold, and long operational lifetime is much significant for truly continuous wave operation and electrically pumping organic lasers. However, most of organic gain media has been verified to have extreme quenching effect from triplet excitons due to its wide‐band distribution of triplet absorption spectrum. Here, it is found that the phenanthroimidazole derivatives as gain media have congenital advantages on handling triplet's issues. A very low amplified spontaneous emission (ASE) threshold of 0.56 µJ cm−2 and a long operational lifetime of 5.77 × 105 pump pulses in air atmosphere are well obtained. When increasing the pump repetition frequency from 20 Hz to 20 kHz, the operational lifetimes of the thin films have small reduction. Under a high pump repetition frequency of 200 kHz, which is quasi‐continuous wave operational regime, the PI2PhDPO thin film exhibits very low ASE threshold of 0.78 µJ cm−2 due to the tiny overlap between triplet absorption and ASE spectra. [ABSTRACT FROM AUTHOR]

We report a photochemical bismuth vanadate (BiVO4) sensing material, which possesses a large proportion of (110) and (011) facets combined with the additional (111) facets, for the selective detection of ultra‐low concentration hydrogen sulfide (H2S) driven by visible light. Specifically, the obtained octadecahedron BiVO4 (Octa‐BiVO4) performs a high response value (67) and short response time (47.4 s) to 100 ppm H2S with good stability for nearly 100 days, as well as undisturbedness by moist air. With the combination of experimental and theoretical calculation results, the adsorption and carrier transfer behaviors of H2S molecules on the Octa‐BiVO4 crystal surface are investigated. By adjusting the ratio of different crystal facets and controlling the facets with characteristic adsorption, we achieve improved anisotropic photoinduced carrier separation and high selectivity for a specific gas. Furthermore, this facial facet engineering can be extended to the synthesis of other sensing materials, offering huge opportunities for fundamental research and technological applications. [ABSTRACT FROM AUTHOR]

"Hot exciton" molecules that allow the transition of excitons from a high‐lying triplet state (Tn, n≥ 2) to singlet states (Sm, m≥1) by a reverse intersystem crossing (hRISC) process have become an effective strategy to achieve high efficiency fluorescence organic light emitting diodes (OLEDs). However, the understanding of the dynamic behavior of the "hot exciton" process is still very lacking. Herein, the exciton dynamics of an aggregation‐induced emission (AIE) molecule TPA‐An‐mPhCz with the "hot exciton" property are deeply investigated, and the proportion between hRISC and internal inversion (IC) of excitons on Tn is successfully quantified by in situ transient electroluminescent measurements and theoretical calculation. It is found that the IC process increases severe energy loss of Tn excitons. By introducing a triplet–triplet annihilation up‐conversion layer in the emissive layer to efficiently recapture the IC excitons and further doping a blue fluorescent emitter in the TPA‐An‐mPhCz layer to achieve high photoluminescence quantum yield (PLQY), the resulting OLED achieves a maximum external quantum efficiency of 12.5% with negligible efficiency roll‐off. More impressively, the operational lifetime LT75 (lifetime to 75% of the initial luminance) of the device with efficient triplets utilization performs a remarkable 116 h under 1000 cd m−2. This work provides the fundamentals for the design of hot exciton materials with efficient exciton utilization to develop efficient blue fluorescence OLEDs. [ABSTRACT FROM AUTHOR]

Aggregation‐induced emission (AIE) materials are attractive for the fabrication of high‐efficiency organic light‐emitting diodes (OLEDs) owing to the "hot exciton" process by reverse intersystem crossing (hRISC) and high photoluminescence quantum yields (PLQY). However, the internal conversion (IC) from the high‐lying triplet excitation states (Tn, n≥2) to the lower excited triplet state (Tn‐1) is inevitable, resulting in severe exciton losses. Herein, an effective device structure is designed that reuses the lost triplet excitons caused by IC and realizes the breakthrough in the efficiency of blue fluorescence OLEDs based on AIE molecule as an emitter. The maximum external quantum efficiency reached as high as 14.8% and is kept at 14.4% at the luminance of 1000 cd m−2. In the designed device, a triplet–triplet annihilation (TTA) up‐conversion material 1‐[2,5‐dimethyl‐4‐(1‐pyrenyl)phenyl]pyrene (DMPPP) is introduced into the AIE emitter as a triplet sensitizer to receive the lost triplet excitons, and a thin TTA up‐conversion layer 9‐[4‐(10‐phenyl‐9‐anthryl)phenyl]‐9H‐carbazole (CzPA) is introduced in the middle of the doped layer to form the emissive layer (EML). It is found that the hRISC process of iTPB‐2AC greatly enhances the utilization efficiency of TTA intermediate state ([TT]*) excitons on CzPA to iTPB‐2AC so that the utilization of the lost excitons is maximized. This work establishes physical insights into the AIE emission materials and device fabrication of high‐efficiency blue fluorescence OLEDs. [ABSTRACT FROM AUTHOR]

The operational lifetime of blue organic light‐emitting diodes (OLEDs) is still insufficient for practical applications in lighting and display. One type of blue organic emitting materials with hybridized local and charge‐transfer (HLCT) process are beneficial in achieving high‐efficiency OLEDs through "hot exciton" channel by harnessing high‐lying triplet (Tn) excitons. However, the operational lifetime of the resulting blue OLEDs is rarely studied and understood. In this article, the aging properties of blue fluorescent OLEDs based on an HLCT material (2‐(4‐(10‐(3‐(9H‐carbazol‐9‐yl)phenyl)anthracen‐9‐yl)phenyl)‐1‐phenyl‐1H‐phenanthro[9,10‐d]imidazole) (PAC) are systematically investigated by exciton dynamics calculation and transient EL experiments. It is experimentally and theoretically revealed that whether the reverse intersystem crossing (hRISC) process from high‐lying excited triplet to singlet in HLCT materials is completely effective determines the device degradation. A fluorescent emitter is doped into PAC host to accelerate the hRISC process, thus enhancing device operational lifetime to reach T75 = 110 ± 2 h (time to 75% of initial luminance) under 1000 cd m−2. This work provides inspirations to investigate the stability of blue fluorescent OLEDs based on HCLT materials and further enhance the operational lifetime. [ABSTRACT FROM AUTHOR]

High‐performance deep‐blue fluorescent materials matching the required Commission Internationale de l'Eclairage y coordinate value (CIEy) of < 0.08 are much‐needed in organic light‐emitting diodes (OLEDs) for realizing the perfect application of full‐color displays. However, deep‐blue fluorophors commonly show unsatisfactory performance due to the intrinsic large bandgap characteristic. Here, the deep‐blue nondoped OLED with the good CIE coordinates of (0.15, 0.07) and external quantum efficiency (EQE) of ≈9% is achieved based on a multifunctional and efficient anthracene‐based fluorophor (2M‐ph‐3CzAnBzt). Using it as a host, the sky‐blue fluorescent OLED realizes the maximum EQE of 9.50%, and keeps as high as 9.27% and 8.56% at 1000 and 5000 cd m−2. More surprisingly, high‐performance hybrid white OLEDs (WOLEDs) with good color stability and low roll‐off are achieved by using it as the blue emitter. Two‐color WOLED shows the forward‐viewing efficiencies of 20.46%, and 76.80 lm W−1. The three‐color WOLED emitting a candlelight with the color rendering index of ≥ 82 realizes the maximum EQE of 21.49% and remains 20.80% at 1000 cd m−2. Such superior electroluminescence performance achieved in these OLEDs ranks among the highest values based on deep‐blue fluorophors with CIEy < 0.08. [ABSTRACT FROM AUTHOR]

Aggregation‐induced emission (AIE) and hybridized local and charge‐transfer (HLCT) materials are two kinds of promising electroluminescence systems for the fabrication of high‐efficiency organic light‐emitting diodes (OLEDs) by harnessing "hot excitons" at the high‐lying triplet exciton states (Tn, n ≥ 2). Nonetheless, the efficiency of the resulting OLEDs did not meet expectations due to the possible loss of Tn→Tn−1. Herein, experimental results and theoretical calculations demonstrate the "hot exciton" process between the high‐lying triplet state T3 and the lowest excited singlet state S1 in an AIE material 4⁗‐(diphenylamino)‐2″,5″‐diphenyl‐[1,1″:4′,1″:4″,1′″:4′″,1⁗‐quinquephenyl]‐4‐carbonitrile (TPB‐PAPC) and it is found that the Förster resonance energy transfer (FRET) between two molecules can facilitate the "hot exciton" process and inhibit the T3→T2 loss by doping a blue fluorescent emitter in TPB‐PAPC. Finally, the doped TPB‐PAPC blue OLEDs achieve a maximum external quantum efficiency (EQEmax) of 9.0% with a small efficiency roll‐off. Furthermore, doping the blue fluorescent emitter in a HLCT material 2‐(4‐(10‐(3‐(9H‐carbazol‐9‐yl)phenyl)anthracen‐9‐yl)phenyl)‐1‐phenyl‐1H‐phenanthro[9,10‐d] imidazole (PAC) is used as the emission layer, and the resulting blue OLEDs exhibit an EQEmax of 17.4%, realizing the efficiency breakthrough of blue fluorescence OLEDs. This work establishes a physical insight in the design of high‐performance "hot exciton" molecules and the fabrication of high‐performance blue fluorescence OLEDs. [ABSTRACT FROM AUTHOR]

Phosphorescent organic light‐emitting diodes (PhOLEDs) using exciplexes as host have achieved unprecedented breakthrough. The energy transfer process between host and guest is the popular way to effectively utilize excitons in this kind of devices. Actually, the intermolecular spin–orbital coupling (ISOC) interaction between the heavy‐atom phosphorescent molecule and exciplex also plays an important role in exciton utilization, thus device performance, but this role is always ignored. Here, the synergistic effects of energy transfer and ISOC interaction on device efficiency are clearly demonstrated in exciplex‐based PhOLEDs by magneto‐electroluminescence (MEL) measurements. It can be seen that the MEL line shape at high field component is significantly wider due to the ISOC effect inducing the accelerated transition process between singlet and triplet states of exciplex host. In this case, the energy transfer process from exciplex host to phosphorescent molecule is more efficient, which is confirmed by the different line widths of MELs. Ultimately, a high‐efficiency exciplex‐based green PhOLED with the maximum external quantum efficiency of 23% is obtained at a low phosphorescent doping concentration of 2 wt%. [ABSTRACT FROM AUTHOR]

Aggregation‐induced emission (AIE) materials are highly attractive because of their excellent properties of high efficiency emission in nondoped organic light‐emitting diodes (OLEDs). Therefore, a deep understanding of the working mechanisms, further improving the electroluminescence (EL) efficiency of the resulting AIE‐based OLEDs, is necessary. Herein, the conversion process from higher energy triplet state (T2) to the lowest singlet state (SS1) is found in OLEDs based on a blue AIE material, 4′‐(4‐(diphenylamino)phenyl)‐5′‐phenyl‐[1,1′:2′,1′′‐terphenyl]‐4‐carbonitrile (TPB‐AC), obviously relating to the device efficiency, by magneto‐EL (MEL) measurements. A special line shape with rise at low field and reduction at high field is observed. The phenomenon is further clarified by theoretical calculations, temperature‐dependent MELs, and transient photoluminescence emission properties. On the basis of the T2‐S1 conversion process, the EL performances of the blue OLEDs based on TPB‐AC are further enhanced by introducing a phosphorescence doping emitter in the emitting layer, which effectively regulates the excitons on TPB‐AC molecules. The maximum external quantum efficiency (EQE) reaches 7.93% and the EQE keeps 7.57% at the luminance of 1000 cd m−2. This work establishes a physical insight for designing high‐performance AIE materials and devices in the future. [ABSTRACT FROM AUTHOR]

Breast cancer, with unsatisfactory survival rates, is the leading cause of cancer‐related death in women worldwide. Recent advances in the genetic basis of breast cancer have benefitted the development of gene‐based medicines and therapies. Tissue engineering technologies, including tissue decellularizations and reconstructions, are potential therapeutic alternatives for cancer research and tissue regeneration. In our study, human breast cancer biopsies were decellularized by a detergent technique, with sodium lauryl ether sulfate (SLES) solution, for the first time. And the decellularization process was optimized to maximally maintain tissue microarchitectures and extracellular matrix (ECM) components with minimal DNA compounds preserved. Histology analysis and DNA quantification results confirmed the decellularization effect with maximal genetic compounds removal. Quantification, immunofluorescence, and histology analyses demonstrated better preservation of ECM components in 0.5% SLES‐treated scaffolds. Scaffolds seeded with MCF‐7 cells demonstrated the process of cell recellularization in vitro, with increased cell migration, proliferation, and epithelial‐to‐mesenchymal transition (EMT) process. When treated with 5‐fluorouracil, the expressions of stem cell markers, including Oct4, Sox2, and CD49F, were maximally maintained in the recellularized scaffold with decreased apoptosis rates compared with monolayer cells. These results showed that the decellularized breast scaffold model with SLES treatments would help to simulate the pathogenesis of breast cancer in vitro. And we hope that this model could further accelerate the development of effective therapies for breast cancer and benefit drug screenings. In our study, human breast cancer biopsies were decellularized by the detergent technique with sodium lauryl ether sulfate (SLES) solution for the first time. Scaffolds seeded with MCF‐7 cells demonstrated the process of cell recellularization in vitro, with increased cell migration, proliferation, and epithelial‐to‐mesenchymal transition (EMT) process. When treated with 5‐fluorouracil (5‐Fu), the expressions of stem cell markers, including Oct4, Sox2, and CD49F, were maximally maintained in the recellularized scaffold with decreased apoptosis rates compared with monolayer cells. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is a leading cause of cancer‐related death in women with unsatisfactory survival rates. Advances in the understanding of the genetic basis of BC provide the opportunity to develop gene‐based medicines capable of treating metastatic diseases. Here, we first demonstrated efficient tissue engineering approaches applied to normal breast and BC extracellular matrix (ECM) starting from decellularized human biopsies to generate a three‐dimensional (3D) bioactive model with the sodium lauryl ether sulfate solution. The decellularized tissues maximized the genetic component removal from tissues and minimally injured ECM structures and native compositions by histology and ECM compositions analyses. Importantly, we proved that the 3D ECM retained tissues biological properties. We demonstrated that after 30 days of recellularization with MCF‐7 cell (human breast adenocarcinoma cell line), the 3D cancer ECM induced an overexpression of epithelial–mesenchymal transition (EMT) and cancer proliferation. Meanwhile, normal ECM from the breast inhibited EMT and cell growth with the inducement of apoptosis. Given the biological activity preserved in the ECM after decellularization, we believe these approaches are powerful tools for future preclinical research for BC and breast development. The decellularized tissues of normal human breast tissues and cancer tissues maximized the genetic component removal from tissues and minimally injured extracellular matrix (ECM) structures and native compositions. After 30 days of recellularization with MCF‐7 cell, the three‐dimensional cancer ECM induced an overexpression of epithelial–mesenchymal transition (EMT) and cancer proliferation. Meanwhile, normal ECM from breast inhibited EMT and cell growth with the inducement of apoptosis. [ABSTRACT FROM AUTHOR]

Abstract: The highly efficient charge generation and transport is realized by simply stacking several 1,4,5,8,9,11‐hexa‐azatriphenylene hexacarbonitrile (HAT‐CN)/4,4′,4″‐tris(N‐3‐methylphenyl‐N‐phenylamino) triph‐enylamine (m‐MTDATA) organic heterojunctions in series. Mechanism analysis confirms that the highly effective charge transport property benefits from the efficient charge generation and recombination processes at the HAT‐CN/m‐MTDATA interfaces. It is found that the efficient multialternating organic heterojunctions can be used not only as hole and electron transporters to supply large charge injection, but also as excellent charge generation layer (CGL) to fabricate high‐performance tandem organic light‐emitting diodes (OLEDs). The resulting red phosphorescent OLEDs by simultaneously using the multialternating organic heterojunctions as hole and electron transporters realize the power efficiency (PE) of 36.7 lm W−1, current efficiency (CE) of 28.0 cd A−1, and external quantum efficiency (EQE) of 15.4%, whereas the PE, CE, and EQE, respectively, reach 37.1 lm W−1, 56.0 cd A−1, and 31.8% when simultaneously using the multialternating organic heterojunctions as hole and electron transporters and CGL to fabricate tandem red phosphorescent OLEDs, indicating the validity of the multialternating organic heterojunctions as the charge generator and transporters. The results provide us a totally new way of fabricating high‐performance OLEDs. [ABSTRACT FROM AUTHOR]

Pluripotent mouse embryonic stem (ES) cells have the ability to generate completely ES cell-derived mice by tetraploid (TE-4N) complementation although; derivation of ES cells from TE-4N animals has not been well defined. In this study, we generated TE-4N mice from high passage number ES cells and, in turn, determined the possibility of deriving ES cells from the TE-4N mice. The results showed that adult fertile TE-4N mice could be generated by aggregation of tetraploid embryos using ES cells passaged 23 times. Furthermore, ES cells could be derived from the TE-4N male mice and as judged by molecular characterisation and a study of chimeras, these ES cells were pluripotent. The findings demonstrate that tetraploid complementation is an efficient way to produce fertile mice, which can then give rise to pluripotent ES cells. [ABSTRACT FROM AUTHOR]

ABSTRACT We have studied the fluorescence of Mg-Al-Eu ternary layered hydroxides (TLH) quenched by tryptophan (Trp). IR spectroscopy was used to evaluate the change of Trp structure which was caused by TLH. XRD and TG-DTA results further suggested a structural change of Trp after being reacted with TLH. XPS characterization confirmed a strong chemical reaction between Trp and TLH. These studies may present more direct evidence to explain the interrelation between the structural change of Trp and the fluorescent quenching of TLH. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

White organic light‐emitting diodes (WOLEDs) are one of the most cogent candidates for environment friendly and healthy solid‐state lighting due to many unique merits. Here, a strategic design of exciplex hosts is applied to simultaneously realize the superior color stability, high color rendering index (CRI), high efficiency, and low efficiency roll‐off properties of WOLEDs. The resulting WOLEDs emit the forward‐viewing maximum power efficiency (PE) of 59.9 lm W−1, and the PE still remains 45.3 and 31.9 lm W−1 at 1000 and 5000 cd m−2, respectively, exhibiting extremely low efficiency roll‐off. More remarkably, the devices also show high CRI over 80 and extremely stable spectral emission in the luminance ranges from 1000 to 15 000 cd m−2. The excellent performances indicate the validity of the structure design and provide a new route for the development of high‐performance WOLEDs. [ABSTRACT FROM AUTHOR]

It is well known that one of the major challenges facing white organic light‐emitting diodes (WOLEDs) has been to achieve high efficiency, low efficiency roll‐off, and high color rendering index (CRI) simultaneously. A simple charge‐ and exciton‐confining emitting layer structure formed by employing a blue emitting p/n heterojunction, and combined with red, yellow, and green phosphorescent ultrathin layers, is presented, thus realizing the stable utilization of 100% excitons. The resulting hybrid WOLEDs exhibit the maximum forward‐viewing external quantum efficiency and power efficiency of 23.4% and 50.4 lm W−1, and keep them at 20.3% and 31.2 lm W−1 at 1000 cd m−2, showing high efficiency and low efficiency roll‐off. Furthermore, the device also shows extremely stable electroluminescent spectra in the whole luminance range with a high CRI of 93 and the Commission Internationale de L'Eclairage coordinates of (0.49, 0.43) at 1000 cd m−2, which is perfect warm white for indoor lighting. The achievement of the excellent comprehensive performances is the best result reported to date among the conventional blue fluorescence‐based hybrid WOLEDs possessing such high CRI, which may be a new starting point for further research on high‐performance hybrid WOLEDs. [ABSTRACT FROM AUTHOR]

OLEDs with high efficiency and low roll‐off are urgently needed to meet the constantly increasing commercial demands for white organic light‐emitting diodes (WOLEDs) in lighting industry applications. To enhance efficiency and decrease WOLED roll‐off, complicated doping technologies are employed, which result in an additional increase in costs. Herein, a deep‐blue‐light molecule (3TPA‐CN) with aggregation‐induced emission (AIE) is introduced as blue emitter and phosphor host to fabricate WOLEDs. By optimizing the emission zones, high efficiency and low roll‐off hybrid WOLEDs are achieved. The maximum forward‐viewing power and external quantum efficiencies reach 86.7 lm W−1 and 22.3%, and remain 59.2 lm W−1 and 19.6% at a luminance of 1000 cd m−2, fully exhibiting the prospect of AIE molecules as a promising electroluminescence material for the fabrication of high‐performance WOLEDs. [ABSTRACT FROM AUTHOR]

In the title compound, [Cu(C(18)H(15)P)(2)(H(2)O)]BF(4), the Cu(I) atom is coordinated by two P atoms from triphenyl-phosphine ligands and one water mol-ecule in a distorted trigonal geometry. In the BF(4) (-) anion, three F atoms are disordered over two sites around the B-F bond, the site-occupancy ratio being 0.67 (6):0.33 (6). The Cu⋯F distance of 2.602 (5) Å between the Cu atom and the ordered F atom may suggest a weak but genuine inter-action. O-H⋯F and weak C-H⋯F hydrogen bonding is present in the crystal structure.