Linearly Arranged Multi-π-Stacked Structure for Efficient Through-Space Charge-Transfer Emitters.

Noncovalent spatial interaction has become an intriguing and important tool for constructing optoelectronic molecules. In this study, we linearly attached three conjugated units in a multi π-stacked manner by using just one trident bridge based on indeno[2,1-b]fluorene. To achieve this structure, we improved the synthetic approach through double C-H activation, significantly simplifying the preparation process. Due to the proximity of the C10, C11, and C12 sites in indeno[2,1-b]fluorene, we derived two novel donor|acceptor|donor (D|A|D) type molecules, 2DMB and 2DMFB, which exhibited closely packed intramolecular stacking, enabling efficient through-space charge transfer. This molecular construction is particularly suitable for developing high-performance thermally activated delayed fluorescence materials. With donor(s) and acceptor(s) constrained and separated within this spatially rigid structure, elevated radiative transition rates, and high photoluminescence quantum yields were achieved. Organic light-emitting diodes incorporating 2DMB and 2DMFB demonstrated superior efficiency, achieving maximum external quantum efficiencies of 28.6% and 16.2%, respectively.

Ligand-solvent coordination enables comprehensive trap passivation for efficient quantum dot near-infrared light-emitting diodes.

Near-infrared light-emitting diodes (NIR LEDs) based on perovskite quantum dots (QDs) have produced external quantum efficiency (EQE) of ~15%. However, these high-performance NIR-QLEDs suffer from immediate carrier quenching because of the accumulation of migratable ions at the surface of the QDs. These uncoordinated ions and carriers - if not bound to the nanocrystal surface - serve as centers for exciton quenching and device degradation. In this work, we overcome this issue and fabricate high-performance NIR QLEDs by devising a ligand anchoring strategy, which entails dissolving the strong-binding ligand (Guanidine Hydroiodide, GAI) in the mediate-polar solvent. By employing the dye-sensitized device structure (phosphorescent indicator), we demonstrate the elimination of the interface defects. The treated QDs films exhibit an exciton binding energy of 117 meV: this represents a 1.5-fold increase compared to that of the control (74 meV). We report, as a result, the NIR QLEDs with an EQE of 21% which is a record among NIR perovskite QLEDs. These QLEDs also exhibit a 7-fold higher operational stability than that of the best previously reported NIR QLEDs. Furthermore, we demonstrate that the QDs are compatible with large-area QLEDs: we showcase 900 mm2 QLEDs with EQE approaching 20%.

Elevated expression of ECT2 as a diagnostic marker and prognostic indicator in endometrial cancer.

OBJECTIVES: The study aimed to investigate the genes linked with the progression of Endometrial cancer (EC) and discover promising new biomarkers for early detection. METHODS: Based on the analysis of differentially expressed genes (DEGs), Series test of cluster (STC) and protein-protein interaction, potential hub genes involved in EC development were identified. The expression pattern, prognostic value, and diagnostic potential of ECT2 were investigated using clinical samples. RESULTS: The DEGs showing an upward trend were significantly enriched in cancer-related processes and pathways. Through validations conducted across additional databases, eight potential hub genes for EC were identified: ASPM, ATAD2, BUB1B, ECT2, KIF14, NUF2, NCAPG, and SPAG5. Particularly, ECT2 exhibited the highest diagnostic efficacy. The expression levels of ECT2 varied significantly across different clinical stages, pathological grades, and metastasis statuses in UCEC. ECT2 mRNA was upregulated in the p53abn group, indicating a poorer prognosis, while it was lower in the MMRd and NSMP groups, indicating a moderate prognosis. In clinical samples, ECT2 showed an increasing trend from normal endometria and endometrial hyperplasia without atypia (EH) to atypical endometrial hyperplasia (AH) and EC. ECT2 effectively distinguished between Normal/EH and AH/EC. Patients with high expression of ECT2 had a more unfavourable prognosis. CONCLUSIONS: The expression of ECT2 is significantly increased in cases of AH and EC. It has shown impressive accuracy in distinguishing between non-malignant and malignant endometria. These findings suggest that ECT2 has the potential to serve as a valuable biomarker for diagnosing endometrial neoplasia and as a prognostic indicator in EC.

Collaborative Human-Computer Vision Operative Video Analysis Algorithm for Analyzing Surgical Fluency and Surgical Interruptions in Endonasal Endoscopic Pituitary Surgery: Cohort Study.

BACKGROUND: The endonasal endoscopic approach (EEA) is effective for pituitary adenoma resection. However, manual review of operative videos is time-consuming. The application of a computer vision (CV) algorithm could potentially reduce the time required for operative video review and facilitate the training of surgeons to overcome the learning curve of EEA. OBJECTIVE: This study aimed to evaluate the performance of a CV-based video analysis system, based on OpenCV algorithm, to detect surgical interruptions and analyze surgical fluency in EEA. The accuracy of the CV-based video analysis was investigated, and the time required for operative video review using CV-based analysis was compared to that of manual review. METHODS: The dominant color of each frame in the EEA video was determined using OpenCV. We developed an algorithm to identify events of surgical interruption if the alterations in the dominant color pixels reached certain thresholds. The thresholds were determined by training the current algorithm using EEA videos. The accuracy of the CV analysis was determined by manual review, and the time spent was reported. RESULTS: A total of 46 EEA operative videos were analyzed, with 93.6%, 95.1%, and 93.3% accuracies in the training, test 1, and test 2 data sets, respectively. Compared with manual review, CV-based analysis reduced the time required for operative video review by 86% (manual review: 166.8 and CV analysis: 22.6 minutes; P<.001). The application of a human-computer collaborative strategy increased the overall accuracy to 98.5%, with a 74% reduction in the review time (manual review: 166.8 and human-CV collaboration: 43.4 minutes; P<.001). Analysis of the different surgical phases showed that the sellar phase had the lowest frequency (nasal phase: 14.9, sphenoidal phase: 15.9, and sellar phase: 4.9 interruptions/10 minutes; P<.001) and duration (nasal phase: 67.4, sphenoidal phase: 77.9, and sellar phase: 31.1 seconds/10 minutes; P<.001) of surgical interruptions. A comparison of the early and late EEA videos showed that increased surgical experience was associated with a decreased number (early: 4.9 and late: 2.9 interruptions/10 minutes; P=.03) and duration (early: 41.1 and late: 19.8 seconds/10 minutes; P=.02) of surgical interruptions during the sellar phase. CONCLUSIONS: CV-based analysis had a 93% to 98% accuracy in detecting the number, frequency, and duration of surgical interruptions occurring during EEA. Moreover, CV-based analysis reduced the time required to analyze the surgical fluency in EEA videos compared to manual review. The application of CV can facilitate the training of surgeons to overcome the learning curve of endoscopic skull base surgery. TRIAL REGISTRATION: ClinicalTrials.gov NCT06156020; https://clinicaltrials.gov/study/NCT06156020.

Modifiable risk factors of immediate and long-term outcomes in the operable and inoperable with left-sided infective endocarditis.

Objectives: To evaluate the outcomes of left-sided infective endocarditis that can be operated on and cannot be operated on, and to focus on modifiable risk factors for immediate and long-term mortality. Methods: This study retrospectively investigated patients with left-sided infective endocarditis who occurred in our medical center between January 2006 and November 2022. Results: 48 in-hospital deaths occurred (5.8 %, 48/832). We identified time from symptoms to admission and symptomatic neurological complications to be risk factors for multiple organ failure upon admission. Time from symptoms to admission and vegetation size in group of isolated medical treatment were significantly shorter than those in the group of heart operation. We also found that preoperative neurological complications, annulus destruction, levels of serum creatinine at 24 and 48 h post heart operation, and perivalvular leakage are risk factors for in-hospital mortality post heart operation. With 148 µmol/L as a cutoff level, the diagnostic sensitivity and specificity of serum creatinine level 48 h post surgery for in-hospital mortality post cardiac surgery are 100 % and 81.6 %, respectively. We found that vegetation size, ICU stay, postoperative serum creatinine at 48 h, left ventricular end diastolic size postoperative, and red blood cell transfusion were associated with all-time mortality. Conclusions: Early diagnosis and treatment, improvement of surgical techniques, good protection for heart, kidney and blood and close follow-up are advocated to conduce to better immediate and long-term outcomes of the operable and inoperable with left-sided infective endocarditis.

The Potential Neurological Impact of Intraoperative Hyponatremia Using Histidine-Tryptophan-Ketoglutarate Cardioplegia Infusion in Adult Cardiac Surgery.

Background and Objectives: The relationship between histidine-tryptophan-ketoglutarate (HTK)-induced hyponatremia and brain injury in adult cardiac surgery patients is unclear. This study analyzed postoperative neurological outcomes after intraoperative HTK cardioplegia infusion. Materials and Methods: A prospective cohort study was conducted on 60 adult patients who underwent cardiac surgery with cardiopulmonary bypass. Of these patients, 13 and 47 received HTK infusion and conventional hyperkalemic cardioplegia, respectively. The patients' baseline characteristics, intraoperative data, brain injury markers, Mini-Mental State Examination (MMSE) scores, and quantitative electroencephalography (qEEG) data were collected. Electrolyte changes during cardiopulmonary bypass, the degree of hyponatremia, and any associated brain insults were evaluated. Results: The HTK group presented with acute hyponatremia during cardiopulmonary bypass, which was intraoperatively corrected through ultrafiltration and normal saline administration. Postoperative sodium levels were higher in the HTK group than in the conventional cardioplegia group. The change in neuron-specific enolase levels after cardiopulmonary bypass was significantly higher in the HTK group (p = 0.043). The changes showed no significant differences using case-control matching. qEEG analysis revealed a significant increase in relative delta power in the HTK group on postoperative day (POD) 7 (p = 0.018); however, no significant changes were noted on POD 60. The MMSE scores were not significantly different between the two groups on POD 7 and POD 60. Conclusions: HTK-induced acute hyponatremia and rapid correction with normal saline during adult cardiac surgeries were associated with a potential short-term but not long-term neurological impact. Further studies are required to determine the necessity of correction for HTK-induced hyponatremia.

Flexible Substrate-Compatible and Efficiency-Improved Quantum-Dot Light-Emitting Diodes with Reduced Annealing Temperature of NiOx Hole-Injecting Layer.

The growing demand for wearable and attachable displays has sparked significant interest in flexible quantum-dot light-emitting diodes (QLEDs). However, the challenges of fabricating and operating QLEDs on flexible substrates persist due to the lack of stable and low-temperature processable charge-injection/-transporting layers with aligned energy levels. In this study, we utilized NiOx nanoparticles that are compatible with flexible substrates as a hole-injection layer (HIL). To enhance the work function of the NiOx HIL, we introduced a self-assembled dipole modifier called 4-(trifluoromethyl)benzoic acid (4-CF3-BA) onto the surface of the NiOx nanoparticles. The incorporation of the dipole molecules through adsorption treatment has significantly changed the wettability and electronic characteristics of NiOx nanoparticles, resulting in the formation of NiO(OH) at the interface and a shift in vacuum level. The alteration of surface electronic states of the NiOx nanoparticles not only improves the carrier balance by reducing the hole injection barrier but also prevents exciton quenching by passivating defects in the film. Consequently, the NiOx-based red QLEDs with interfacial modification demonstrate a maximum current efficiency of 16.1 cd/A and a peak external quantum efficiency of 10.3%. This represents a nearly twofold efficiency enhancement compared to control devices. The mild fabrication requirements and low annealing temperatures suggest potential applications of dipole molecule-modified NiOx nanoparticles in flexible optoelectronic devices.

Bilateral Production Shield Enabling Highly Efficient Perovskite Photovoltaics.

Enhancing the intrinsic stability of perovskite and through encapsulation to isolate water, oxygen, and UV-induced decomposition are currently common and most effective strategies in perovskite solar cells. Here, the atomic layer deposition process is employed to deposit a nanoscale (≈100 nm), uniform, and dense Al2O3 film on the front side of perovskite devices, effectively isolating them from the erosion caused by water and oxygen in the humid air. Simultaneously, nanoscale (≈100 nm) TiO2 films are also deposited on the glass surface to efficiently filter out the ultraviolet (UV) light in the light source, which induces degradation in perovskite. Ultimately, throughthe collaborative effects of both aspects, the stability of the devices is significantly improved under conditions of humid air and illumination. As a result, after storing the devices in ambient air for 1000 h, the efficiency only declines to 95%, and even after 662 h of UV exposure, the efficiency remains at 88%, far surpassing the performance of comparison devices. These results strongly indicate that the adopted Al2O3 and TiO2 thin films play a significant role in enhancing the stability of perovskite solar cells, demonstrating substantial potential for widespread industrial applications.

Long-range order enabled stability in quantum dot light-emitting diodes.

Light-emitting diodes (LEDs) based on perovskite quantum dots (QDs) have produced external quantum efficiencies (EQEs) of more than 25% with narrowband emission1,2, but these LEDs have limited operating lifetimes. We posit that poor long-range ordering in perovskite QD films-variations in dot size, surface ligand density and dot-to-dot stacking-inhibits carrier injection, resulting in inferior operating stability because of the large bias required to produce emission in these LEDs. Here we report a chemical treatment to improve the long-range order of perovskite QD films: the diffraction intensity from the repeating QD units increases three-fold compared with that of controls. We achieve this using a synergistic dual-ligand approach: an iodide-rich agent (aniline hydroiodide) for anion exchange and a chemically reactive agent (bromotrimethylsilane) that produces a strong acid that in situ dissolves smaller QDs to regulate size and more effectively removes less conductive ligands to enable compact, uniform and defect-free films. These films exhibit high conductivity (4 × 10-4 S m-1), which is 2.5-fold higher than that of the control, and represents the highest conductivity recorded so far among perovskite QDs. The high conductivity ensures efficient charge transportation, enabling red perovskite QD-LEDs that generate a luminance of 1,000 cd m-2 at a record-low voltage of 2.8 V. The EQE at this luminance is more than 20%. Furthermore, the stability of the operating device is 100 times better than previous red perovskite LEDs at EQEs of more than 20%.

Near-Infrared Luminescent Materials Incorporating Rare Earth/Transition Metal Ions: From Materials to Applications.

The spotlight has shifted to near-infrared (NIR) luminescent materials emitting beyond 1000 nm, with growing interest due to their unique characteristics. The ability of NIR-II emission (1000-1700 nm) to penetrate deeply and transmit independently positions these NIR luminescent materials for applications in optical-communication devices, bioimaging, and photodetectors. The combination of rare earth metals/transition metals with a variety of matrix materials provides a new platform for creating new chemical and physical properties for materials science and device applications. In this review, the recent advancements in NIR emission activated by rare earth and transition metal ions are summarized and their role in applications spanning bioimaging, sensing, and optoelectronics is illustrated. It started with various synthesis techniques and explored how rare earths/transition metals can be skillfully incorporated into various matrixes, thereby endowing them with unique characteristics. The discussion to strategies of enhancing excitation absorption and emission efficiency, spotlighting innovations like dye sensitization and surface plasmon resonance effects is then extended. Subsequently, a significant focus is placed on functionalization strategies and their applications. Finally, a comprehensive analysis of the challenges and proposed strategies for rare earth/transition metal ion-doped near-infrared luminescent materials, summarizing the insights of each section is provided.

Customizable Organic Charge-Transfer Cocrystals for the Dual-Mode Optoelectronics in the NIR (II) Window.

Organic molecules have been regarded as ideal candidates for near-infrared (NIR) optoelectronic active materials due to their customizability and ease of large-scale production. However, constrained by the intricate molecular design and severe energy gap law, the realization of optoelectronic devices in the second near-infrared (NIR (II)) region with required narrow band gaps presents more challenges. Herein, we have originally proposed a cocrystal strategy that utilizes intermolecular charge-transfer interaction to drive the redshift of absorption and emission spectra of a series BFXTQ (X = 0, 1, 2, 4) cocrystals, resulting in the spectra located at NIR (II) window and reducing the optical bandgap to ∼0.98 eV. Significantly, these BFXTQ-based optoelectronic devices can exhibit dual-mode optoelectronic characteristics. An investigation of a series of BFXTQ-based photodetectors exhibits detectivity (D*) surpassing 1013 Jones at 375 to 1064 nm with a maximum of 1.76 × 1014 Jones at 1064 nm. Moreover, the radiative transition of CT excitons within the cocrystals triggers NIR emission over 1000 nm with a photoluminescence quantum yield (PLQY) of ∼4.6% as well as optical waveguide behavior with a low optical-loss coefficient of 0.0097 dB/µm at 950 nm. These results promote the advancement of an emerging cocrystal approach in micro/nanoscale NIR multifunctional optoelectronics.

Virtual draw of microstructured optical fiber based on physics-informed neural networks.

The implementation of microstructured optical fibers (MOFs) with novel micro-structures and perfect performance is challenging due to the complex fabrication processes. Physics-informed neural networks (PINNs) offer what we believe to be a new approach to solving complex partial differential equations within the virtual fabrication model of MOFs. This study, for what appears to be the first time, integrates the complex partial differential equations and boundary conditions describing the fiber drawing process into the loss function of a neural network. To more accurately solve the free boundary of the fiber's inner and outer diameters, we additionally construct a neural network to describe the free boundary conditions. This model not only captures the evolution of the fiber's inner and outer diameters but also provides the velocity distribution and pressure distribution within the molten glass, thus laying the foundation for a quantitative analysis of capillary collapse. Furthermore, results indicate that the trends in the effects of temperature, feed speed, and draw speed on the fiber drawing process align with actual fabrication conditions, validating the feasibility of the model. The methodology proposed in this study offers what we believe to be a novel approach to simulating the fiber drawing process and holds promise for advancing the practical applications of MOFs.

Enhancing Light Outcoupling Efficiency via Anisotropic Low Refractive Index Electron Transporting Materials for Efficient Perovskite Light-Emitting Diodes.

Thanks to the extensive efforts toward optimizing perovskite crystallization properties, high-quality perovskite films with near-unity photoluminescence quantum yield are successfully achieved. However, the light outcoupling efficiency of perovskite light-emitting diodes (PeLEDs) is impeded by insufficient light extraction, which poses a challenge to the further advancement of PeLEDs. Here, an anisotropic multifunctional electron transporting material, 9,10-bis(4-(2-phenyl-1H-benzo[d]imidazole-1-yl)phenyl) anthracene (BPBiPA), with a low extraordinary refractive index (ne) and high electron mobility is developed for fabricating high-efficiency PeLEDs. The anisotropic molecular orientations of BPBiPA can result in a low ne of 1.59 along the z-axis direction. Optical simulations show that the low ne of BPBiPA can effectively mitigate the surface plasmon polariton loss and enhance the photon extraction efficiency in waveguide mode, thereby improving the light outcoupling efficiency of PeLEDs. In addition, the high electron mobility of BPBiPA can facilitate balanced carrier injection in PeLEDs. As a result, high-efficiency green PeLEDs with a record external quantum efficiency of 32.1% and a current efficiency of 111.7 cd A-1 are obtained, which provides new inspirations for the design of electron transporting materials for high-performance PeLEDs.

Next-generation sequencing reveals genetic heterogeneity and resistance mechanisms in patients with EGFR-mutated non-small cell lung cancer treated with afatinib.

Background: Afatinib, an irreversible ErbB family inhibitor, is widely used as first-line treatment in advanced lung adenocarcinoma patients harbouring mutant epidermal growth factor receptor (EGFR). With the advancements in next-generation sequencing (NGS), comprehensive research into the clinical impact of co-occurring genetic mutations and the molecular mechanisms of acquired resistance is required for afatinib users. Materials: From January 2010 to December 2019, we enrolled patients with advanced lung adenocarcinoma with EGFR mutations using afatinib as first-line treatment, and we retrospectively collected pre- and post-afatinib treatment specimens from these patients for NGS testing. Results: Of the 362 enrolled patients, 73 samples (68.9%) from 56 patients successfully returned complete NGS reports. In pre-afatinib treatment specimens, the most frequent co-occurring alterations were TP53, MUC16, USH2A, SNYE1, RECQL4 and FAT1; however, they were not related to progression-free survival. Small cell lung cancer transformation, EGFR p.T790M, amplification of MET, ERBB2, KRAS, EGFR, cell cycle-regulated genes and MDM2, and PTEN alterations were identified as acquired resistance mechanisms. EGFR p.T790M (p=0.0304) and APC alterations (p=0.0311) in post-afatinib specimens were significantly associated with longer overall survival, while MET amplification was significantly associated with poor overall survival (p=0.0324). The co-occurrence of TP53 alterations was significantly associated with shorter overall survival (p=0.0298). Conclusions: Our results show that the frequent co-occurring alterations in advanced EGFR-mutated lung adenocarcinoma did not influence the effectiveness of afatinib. EGFR p.T790M is not only the major resistance mechanism to afatinib but also related to favourable survival outcomes. MET amplification and TP53 mutations were associated with poorer overall survival.

[Screening of bioactive components endowing hawthorn with turbidity-eliminating and lipid-lowering functions and development of quality control method of hawthorn].

Hawthorn has the efficacy of eliminating turbidity and lowering the blood lipid level, and it is used for treating hyperlipidemia in clinic. However, the bioactive components of hawthorn are still unclear. In this study, the spectrum-effect relationship was employed to screen the bioactive components of hawthorn in the treatment of hyperlipidemia, and then the bioactive components screened out were verified in vivo. Furthermore, the quality control method for hawthorn was developed based on liquid chromatography-mass spectrometry(LC-MS). The hyperlipidemia model of rats was built, and different polar fractions of hawthorn extracts and their combinations were administrated by gavage. The effects of different hawthorn extract fractions on the total cholesterol(TC), triglycerides(TG), and low-density lipoprotein-cholesterol(LDL-C) in the serum of model rats were studied. The orthogonal projections to latent structures(OPLS) algorithm was used to establish the spectrum-effect relationship model between the 24 chemical components of hawthorn and the pharmacodynamic indexes, and the bioactive components were screened out and verified in vivo. Finally, 10 chemical components of hawthorn, including citric acid and quinic acid, were selected to establish the method for evaluating hawthorn quality based on LC-MS. The results showed that different polar fractions of hawthorn extracts and their combinations regulated the TG, TC, and LDL-C levels in the serum of the model rats. The bioactive components of hawthorn screened by the OPLS model were vitexin-4″-O-glucoside, vitexin-2″-O-rhamnoside, rutin, citric acid, malic acid, and quinic acid. The 10 chemical components of hawthorn, i.e., citric acid, quinic acid, rutin, gallic acid, vitexin-4″-O-glucoside, vitexin-2″-O-rhamnoside, malic acid, vanillic acid, neochlorogenic acid, and fumaric acid were determined, with the average content of 38, 11, 0.018, 0.009 5, 0.037, 0.017, 8.1, 0.009 5, 0.073, and 0.98 mg·g~(-1), respectively. This study provided a scientific basis for elucidating the material basis of hawthorn in treating hyperlipidemia and developed a content determination method for evaluating the quality of hawthorn.

Polarity-Mediated Antisolvent Control Enables Efficient Lanthanide-Based near-Infrared Perovskite LEDs.

Alloying lanthanide ions (Yb3+) into perovskite quantum dots (Yb3+:CsPb(Cl1-xBrx)3) is an effective method to achieve efficient near-infrared (NIR) luminescence (>950 nm). Increasing the Yb3+ alloying ratio in the perovskite matrix enhances the luminescence intensity of Yb3+ emission at 990 nm. However, high Yb3+ alloying (>15%) results in vacancy-induced inferior material stability. In this work, we developed a polarity-mediated antisolvent manipulation strategy to resolve the incompatibility between a high Yb3+ alloying ratio and inferior stability of Yb3+:CsPb(Cl1-xBrx)3. Precise control of solution polarity enables increased uniformity of the perovskite matrix with fewer trap densities. Employing this strategy, we obtain Yb3+:CsPb(Cl1-xBrx)3 with the highest Yb3+ alloying ratio of 30.2% and a 2-fold higher electroluminescence intensity at 990 nm. We lever the engineered Yb3+:CsPb(Cl1-xBrx)3 to fabricate NIR-LEDs, achieving a peak external quantum efficiency (EQE) of 8.5% at 990 nm: this represents the highest among perovskite NIR-LEDs with an emission wavelength above 950 nm.

In Situ Hydrolysis of Phosphate Enabling Sky-Blue Perovskite Light-Emitting Diode with EQE Approaching 16.32.

The performance of blue perovskite light-emitting diodes (PeLEDs) lags behind the green and red counterparts owing to high trap density and undesirable red shift of the electroluminescence spectrum under operation conditions. Organic molecular additives were employed as passivators in previous reports. However, most commonly have limited functions, making it challenging to effectively address both efficiency and stability issues simultaneously. Herein, we reported an innovatively dynamic in situ hydrolysis strategy to modulate quasi-2D sky-blue perovskites by the multifunctional passivator phenyl dichlorophosphate that not only passivated the defects but also underwent in situ hydrolysis reaction to stabilize the emission. Moreover, hydrolysis products were beneficial for low-dimensional phase manipulation. Eventually, we obtained high-performance sky-blue PeLEDs with a maximum external quantum efficiency (EQE) of 16.32% and an exceptional luminance of 5740 cd m-2. More importantly, the emission peak of devices located at 485 nm remained stable under different biases. Our work signified the significant advancement toward realizing future applications of PeLEDs.

Visualizing the interfacial-layer-based epitaxial growth process toward organic core-shell architectures.

Organic heterostructures (OHTs) with the desired geometry organization on micro/nanoscale have undergone rapid progress in nanoscience and nanotechnology. However, it is a significant challenge to elucidate the epitaxial-growth process for various OHTs composed of organic units with a lattice mismatching ratio of > 3%, which is unimaginable for inorganic heterostructures. Herein, we have demonstrated a vivid visualization of the morphology evolution of epitaxial-growth based on a doped interfacial-layer, which facilitates the comprehensive understanding of the hierarchical self-assembly of core-shell OHT with precise spatial configuration. Significantly, the barcoded OHT with periodic shells obviously illustrate the shell epitaxial-growth from tips to center parts along the seeded rods for forming the core-shell OHT. Furthermore, the diameter, length, and number of periodic shells were modulated by finely tuning the stoichiometric ratio, crystalline time, and temperature, respectively. This epitaxial-growth process could be generalized to organic systems with facile chemical/structural compatibility for forming the desired OHTs.

Effects of Deuterium Isotopes on Pt(II) Complexes and Their Impact on Organic NIR Emitters.

Insight into effect of deuterium isotopes on organic near-IR (NIR) emitters was explored by the use of self-assembled Pt(II) complexes H-3-f and HPh-3-f, and their deuterated analogues D-3-f and DPh-3-f, respectively (Scheme 2). In vacuum deposited thin film, albeit having nearly identical emission spectral feature maximized at ~810 nm, H-3-f and D-3-f exhibit remarkable difference in photoluminescence quantum yield (PLQY) of 29 % and 50 %, respectively. Distinction in PLQY is also observed for HPh-3-f (800 nm, 50 %) and DPh-3-f (798 nm, 67 %). We then elucidated the theoretical differences in the impact on near-infrared (NIR) luminescence between Pt(II) complexes and organic small molecules upon deuteration. The results establish a general guideline for the deuteration on NIR emission efficiency. From a perspective of practical application, NIR OLEDs based on D-3-f and DPh-3-f emitters attain EQEmax of 15.5 % (radiance 31,287 mW Sr-1 m-2 ) and 16.6 % (radiance of 32,279 mW Sr-1 m-2 ) at 764 nm and 796 nm, respectively, both of which set new records for NIR OLEDs of >750 nm.

High-throughput virtual screening of organic second-order nonlinear optical chromophores within the donor-π-bridge-acceptor framework.

In view of the theoretical importance and huge application potential of second-order nonlinear optical (NLO) materials, it is of great significance to conduct high-throughput virtual screening (HTVS) on a compound library to find candidate NLO chromophores. Under the donor-π-bridge-acceptor structural framework, a virtual compound library (size = 27 090) was constructed by enumeration of structural fragments. The kernel property adopted for optimization is the static first hyperpolarizability (ß0). By combining machine learning and quantum chemical calculations, we have performed an HTVS procedure to sieve NLO chromophores out, and the response mechanism of the selected optimal NLO chromophores was examined. We have found: (a) The multi-layer perceptron/extended connectivity fingerprint combination with 20% selection ratio gives the highest prediction accuracy for the studied systems. (b) The two optimal donors are bis(4-diphenylaminophenyl)aminyl and bis(4-tert-butylphenyl)aminyl; the optimal π-bridges are composed of two thiophenyl, selenophenyl or furanyl units; and the two optimal acceptors are tri-s-triazinyl and 2,3-dicyanopyrazinyl. (c) The no. 1 candidate molecule can exhibit a calculated ß0 equal to 8.55 × 104 a.u. (d) The difference in NLO responses of the optimal 16 molecules comes from the synergistic interaction of ES1, Δµ and f, by employing the two-level model. In addition, the sizable Δµ and f allow the studied optimal molecules to obtain a large NLO response in the meantime keeping a not-too-low excitation energy (retaining good optical transparency in the restricted range of the visible spectrum region). (e) With further modification on the acceptor, the designed DPA-π-TRZ-A' (A' = CN or NO2, π = oligo-thiophenyl or selenophenyl) systems can exhibit a rather large NLO response (maximum ß0 = 3.17 × 105 a.u.), hence should have considerable potential as second-order NLO chromophores. With the above observations, we expect to provide some insight for the research community into the HTVS of organic second-order NLO chromophores.