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Perovskite quantum dots have been proven promising for photonic and optoelectronic applications, particularly, as bright and narrow band emitters for display technology. Despite the advantageous properties, the stability issues have to be resolved to unleash the full industrial potential of perovskite quantum dots in display technology.

For the state-of-the-art quantum dot light-emitting diodes, while the ZnO nanoparticle layers can provide effective electron injections into quantum dots layers, the hole transporting materials usually cannot guarantee sufficient hole injection owing to the deep valence band of quantum dots. Developing proper hole transporting materials to match energy levels with quantum dots remains a great challenge to further improve the device efficiency and operation lifetime. Here we demonstrate high-performance quantum dot light-emitting diodes with much extended operation lifetime using quantum dots with tailored energy band structures that are favorable for hole injections. These devices show a T 95 operation lifetime of more than 2300 h with an initial brightness of 1000 cd m −2 , and an equivalent T 50 lifetime at 100 cd m −2 of more than 2,200,000 h, which meets the industrial requirement for display applications. The commercialization of light-emitting diodes based on emissive quantum dots (e.g. QLEDs) is hindered by their inherent poor operational lifetime. Using an intelligent energy-level design strategy, Qian et al. demonstrate QLEDs with operational lifetime that meets industrial display standards.

To industrialize printed full-color displays based on quantum-dot light-emitting diodes, one must explore the degradation mechanism and improve the operational stability of blue electroluminescence. Here, we report that although state-of-the-art blue quantum dots, with monotonically-graded core/shell/shell structures, feature near-unity photoluminescence quantum efficiency and efficient charge injection, the significant surface-bulk coupling at the quantum-dot level, revealed by the abnormal dipolar excited state, magnifies the impact of surface localized charges and limits operational lifetimes. Inspired by this, we propose blue quantum dots with a large core and an intermediate shell featuring nonmonotonically-graded energy levels. This strategy significantly reduces surface-bulk coupling and tunes emission wavelength without compromising charge injection. Using these quantum dots, we fabricate bottom-emitting devices with emission colors varying from near-Rec.2020-standard blue to sky blue. At an initial luminance of 1000 cd m −2 , these devices exhibit T 95 operational lifetimes ranging from 75 to 227 h, significantly surpassing the existing records. The surface localized charges in colloidal quantum dots induce a degradation that limits the electroluminescence performance. Here, Chen et al. propose quantum dots with monmonotonically-graded core/shell/shell structures to boost the device’s performance by reducing the surface-bulk coupling.

The operating lifetime of blue quantum-dot light-emitting diodes (QLED) is currently a short slab for this emerging display technology. To pinpoint the origin of device degradation, here we apply multiple techniques to monitor the electric-field distribution and space-charge accumulation across the multilayered structure before and after lifetime tests. Evident by charge-modulated electro-absorption and capacitance-voltage characteristics, the excited electrons in blue quantum dots (QD) are prone to cross the type II junction between the QD emission layer and the electron-transporting layer (ETL) due to the offset of conduction band minimum, leading to space-charge accumulation and operating-voltage rise in the ETL. Therefore, unlike those very stable red devices, of which the lifetime is primarily limited by the slow degradation of hole-transporting layer, the poor lifetime of blue QLED originates from the fast degradation at the QD-ETL junction. Materials engineering for efficient electron injection is prerequisite for the boost of operating lifetime. Wide application of quantum dot light emitting diodes (QLED) in display technology is hindered by the poor lifetime of the blue QLEDs. Here, the degradation mechanism is shown to originate from space charge accumulation in the electron-transporting layer enabling improvements in blue QLED lifetimes.

The low efficiency and fast degradation of devices from ink-jet printing process hinders the application of quantum dot light emitting diodes on next generation displays. Passivating the trap states caused by both anion and cation under-coordinated sites on the quantum dot surface with proper ligands for ink-jet printing processing reminds a problem. Here we show, by adapting the idea of dual ionic passivation of quantum dots, ink-jet printed quantum dot light emitting diodes with an external quantum efficiency over 16% and half lifetime of more than 1,721,000 hours were reported for the first time. The liquid phase exchange of ligands fulfills the requirements of ink-jet printing processing for possible mass production. And the performance from ink-jet printed quantum dot light emitting diodes truly opens the gate of quantum dot light emitting diode application for industry. Designing efficient and scalable quantum dot LEDs meeting industrial requirements remains a challenge. Here, the authors, by leveraging the liquid phase exchange of d-MX 2 ligands, present printed quantum dot LEDs with external quantum efficiency over 16% and half lifetime of more than 1,721,000 hours.

Colloidal quantum dot (QD) emitters show great promise in the development of next-generation displays. Although various solution-processed techniques have been developed for nanomaterials, high-resolution and uniform patterning technology amicable to manufacturing is still missing. Here, we present large-area, high-resolution, full-color QD patterning utilizing a selective electrophoretic deposition (SEPD) technique. This technique utilizes photolithography combined with SEPD to achieve uniform and fast fabrication, low-cost QD patterning in large-area beyond 1,000 pixels-per-inch. The QD patterns only deposited on selective electrodes with precisely controlled thickness in a large range, which could cater for various optoelectronic devices. The adjustable surface morphology, packing density and refractive index of QD films enable higher efficiency compared to conventional solution-processed methods. We further demonstrate the versatility of our approach to integrate various QDs into large-area arrays of full-color emitting pixels and QLEDs with good performance. The results suggest a manufacture-viable technology for commercialization of QD-based displays. Colloidal quantum dots are promising for next-generation displays, yet the technology to realise high-resolution and uniform patterning is still scarce. Here, the authors report full-colour QD large area patterning by combining photolithography and selective electrophoretic deposition technique.

The feasibility was explored for synergistic addition of coal slime and silica calcium slag for saline-alkali soil improvement. A pot method was used to evaluate the effects on physicochemical properties of saline-alkali soil and wheat growth. The results demonstrated that the density and bulk density of saline-alkali soil were reduced with the synergistic additions, but the water content and the contents of organic matter, nitrogen, phosphorus, and potassium in the soil were increased. The emergence and growth height of wheat seedlings was found to be effectively improved. In terms of the emergence, no matter what proportion of M-G (coal slime: silica calcium slag ratio) was used, the emergence of wheat was greater than 70% when the addition amount was at 20%. In terms of seedling length, when the aggregate addition reached 35%, the high coal slime content (M-G 3:1) did not play a greater role in fostering the development of wheat. Therefore, with M-G 1:1, 35% addition of the soil can meet the growth needs of wheat in the early stage. In summary, the synergistic addition of coal slime and silica calcium slag has a promising application in the field of saline-alkali soil improvement.

With its high theoretical capacity, lithium (Li) metal is recognized as the most potential anode for realizing a high‐performance energy storage system. A series of questions (severe safety hazard, low Coulombic efficiency, short lifetime, etc.) induced by uncontrollable dendrites growth, unstable solid electrolyte interface layer, and large volume change, make practical application of Li‐metal anodes still a threshold. Due to their highly appealing properties, carbon‐based materials as hosts to composite with Li metal have been passionately investigated for improving the performance of Li‐metal batteries. This review displays an overview of the critical role of carbon‐based hosts for improving the comprehensive performance of Li‐metal anodes. Based on correlated mainstream models, the main failure mechanism of Li‐metal anodes is introduced. The advantages and strategies of carbon‐based hosts to address the corresponding challenges are generalized. The unique function, existing limitation, and recent research progress of key carbon‐based host materials for Li‐metal anodes are reviewed. Finally, a conclusion and an outlook for future research of carbon‐based hosts are presented. This review is dedicated to summarizing the advances of carbon‐based materials hosts in recent years and providing a reference for the further development of carbon‐based hosts for advanced Li‐metal anodes. Graphical Carbon‐based hosts are of great significance for the future development of high‐performance Li‐metal anodes. This review summarizes the recent developments of carbon‐based hosts for Li‐metal accommodation. The carbon‐based hosts with high surface area and conductivity can suppress dendrites growth, relieve volume expansion, and stabilize interface, and further doping and compositing to the hosts can effectively regulate Li plating/stripping behaviors.

Introduction: Lactate levels, a marker of tissue hypoxia and metabolic acidosis, have been suggested as a prognostic indicator for patient outcomes in pneumonia. This systematic review and meta-analysis aim to determine the predictive value of lactate levels for mortality in patients with pneumonia. Methods: A systematic literature search was done using CINAHL, SCOPUS, EMBASE, MEDLINE, Cochrane, Google Scholar, and ScienceDirect databases. Random-effect models were used to calculate pooled effect estimates, including sensitivity, specificity, and diagnostic odds ratios. Heterogeneity, publication bias, and meta-regression analyses were performed. Results: A total of 17 studies were included. The pooled diagnostic odds ratio for lactate levels in predicting mortality was 5 (95% CI: 3-8). The sensitivity and specificity were 61% (95% CI: 52 - 69%) and 78% (95% CI: 73 - 82%), respectively. The positive and negative likelihood ratios were 2.7 (95% CI: 2.1-3.4) and 0.51 (95% CI: 0.40-0.64). The area under the receiver operating characteristic curve was 0.77 (95% CI: 0.72-0.82). Subgroup analysis showed that studies with lactate cut-off values between 1.2 and 2 mmol/L had better sensitivity, while studies with cut-off values greater than 2 mmol/L had higher specificity. Conclusions: Lactate levels have moderate predictive value for mortality in patients with pneumonia. This indicator may potentially aid in risk stratification and clinical decision-making. Further research is needed to determine optimal lactate cut-off values and evaluate the potential benefits of incorporating lactate monitoring into pneumonia management strategies.

Cancer-related burden of morbidity and mortality is rapidly rising worldwide. Medical imaging plays an important role in every phase of cancer management, including diagnosis, staging, treatment planning and evaluation. Iron oxide nanoparticles (IONPs) could serve as contrast agents or labeling agents to enhance the identification and visualization of pathological tissues as well as target cells. Multimodal or multifunctional imaging can be easily acquired by modifying IONPs with other imaging agents or functional groups, allowing the accessibility of combined imaging techniques and providing more comprehensive information for cancer care. To date, IONPs-enhanced medical imaging has gained intensive application in early diagnosis, monitoring treatment as well as guiding radio-frequency ablation, sentinel lymph node dissection, radiotherapy and hyperthermia therapy. Besides, IONPs mediated imaging is also capable of promoting the development of anti-cancer nanomedicines through identifying patients potentially sensitive to nanotherapeutics. Based on versatile imaging modes and application fields, this review highlights and summarizes recent research advances of IONPs-based medical imaging in cancer management. Besides, currently existing challenges are also discussed to provide perspectives and advices for the future development of IONPs-based imaging in cancer management.