Poly(ethylene) Oxide Electrolytes for All-Solid-State Lithium Batteries Using Microsized Silicon/Carbon Anodes with Enhanced Rate Capability and Cyclability.

Silicon (Si) has been widely studied as one of the promising anodes for lithium-ion batteries (LIBs) because of its ultrahigh theoretical specific capacity and low working voltage. However, the poor interfacial stability of silicon against conventional liquid electrolytes has largely impeded its practical use. Therefore, the combination of silicon-based anodes and solid electrolytes has attracted a great deal of attention in recent years. Here, we demonstrate three types of microsized porous silicon/carbon (Si/C) electrodes (i.e., pristine, prelithiated by liquid electrolyte, and preinfiltrated by polymer electrolyte) that are paired with poly(ethylene) oxide (PEO)-based electrolytes for all-solid-state lithium batteries (ASSLBs). We found that when compared with ionic conductivity, the mechanical stability of the PEO electrolyte dominates the electrochemical performance of ASSLBs using Si/C electrodes at elevated temperature. Additionally, both prelithiated and preinfiltrated Si/C electrodes show higher specific capacity in comparison to the pristine electrode, which is attributed to continuous lithium-ion conducting pathways within the electrode and thus improved utilization of active material. Moreover, owing to good interfacial lithium-ion transport in the electrode, a solid-state half-cell with preinfiltrated Si/C electrode and PEO-lithium bis (trifluoromethanesulfonyl)imide electrolyte delivers a specific capacity of ∼1,000 mAh g-1 after 100 cycles under 800 mA g-1 at 60 °C with average Coulombic efficiency >98.9%. This work provides a strategy for rationally designing the microstructure of silicon-based electrodes with solid electrolytes for high-performance all-solid-state lithium batteries.

Mixed-Dimensional Integration of 3D-on-2D Heterostructures for Advanced Electronics.

Two-dimensional (2D) materials have garnered significant attention due to their exceptional properties requisite for next-generation electronics, including ultrahigh carrier mobility, superior mechanical flexibility, and unusual optical characteristics. Despite their great potential, one of the major technical difficulties toward lab-to-fab transition exists in the seamless integration of 2D materials with classic material systems, typically composed of three-dimensional (3D) materials. Owing to the self-passivated nature of 2D surfaces, it is particularly challenging to achieve well-defined interfaces when forming 3D materials on 2D materials (3D-on-2D) heterostructures. Here, we comprehensively review recent progress in 3D-on-2D incorporation strategies, ranging from direct-growth- to layer-transfer-based approaches and from non-epitaxial to epitaxial integration methods. Their technological advances and obstacles are rigorously discussed to explore optimal, yet viable, integration strategies of 3D-on-2D heterostructures. We conclude with an outlook on mixed-dimensional integration processes, identifying key challenges in state-of-the-art technology and suggesting potential opportunities for future innovation.

The future of two-dimensional semiconductors beyond Moore's law.

The primary challenge facing silicon-based electronics, crucial for modern technological progress, is difficulty in dimensional scaling. This stems from a severe deterioration of transistor performance due to carrier scattering when silicon thickness is reduced below a few nanometres. Atomically thin two-dimensional (2D) semiconductors still maintain their electrical characteristics even at sub-nanometre scales and offer the potential for monolithic three-dimensional (3D) integration. Here we explore a strategic shift aimed at addressing the scaling bottleneck of silicon by adopting 2D semiconductors as new channel materials. Examining both academic and industrial viewpoints, we delve into the latest trends in channel materials, the integration of metal contacts and gate dielectrics, and offer insights into the emerging landscape of industrializing 2D semiconductor-based transistors for monolithic 3D integration.

Thermal Dehydrogenation Impact on Positive Bias Stability of Amorphous InSnZnO Thin-Film Transistors.

Recently, the growing demand for amorphous oxide semiconductor thin-film transistors (AOS TFTs) with high mobility and good stability to implement ultrahigh-resolution displays has made tracking the role of hydrogen in oxide semiconductor films increasingly important. Hydrogen is an essential element that contributes significantly to the field effect mobility and bias stability characteristics of AOS TFTs. However, because hydrogen is the lightest atom and has high reactivity to metal and oxide materials, elucidating its impact on AOS thin films has been challenging. Therefore, in this study, we propose controlling the hydrogen quantities in amorphous InSnZnO (a-ITZO) thin films through thermal dehydrogenation to precisely reveal the hydrogen influences on the electrical characteristics of a-ITZO TFTs. The as-deposited device containing 15.69 × 1015 atoms/cm2 of hydrogen exhibited a relatively low saturation mobility of 18.1 cm2/V·s and poor positive bias stress stability. However, depending on the extent of thermal dehydrogenation, not only did the hydrogen quantity and interface defect density (DIT) decrease but also the conductivity and surface energy increased due to the rise in oxygen vacancies and hydroxyl groups in a-ITZO thin films. As a result, the a-ITZO TFT with a hydrogen amount of 4.828 × 1015 atoms/cm2 showed that the saturation mobility improved up to 36.8 cm2/V·s, and positive bias stress stability was remarkably enhanced. Hence, we report the ability to manage the hydrogen quantity with thermal dehydrogenation and demonstrate that high-performance a-ITZO TFTs can be realized when an appropriate hydrogen concentration is achieved.

Preventive effect of aripiprazole once-monthly on relapse into mood episodes in bipolar disorder: A multicenter, one-year, retrospective, mirror image study.

BACKGROUND: We conducted a one-year, retrospective, mirror-image study to investigate the clinical effectiveness and safety of aripiprazole once monthly (AOM) in patients with bipolar disorder (BD). We compared pre-treatment conditions with outcomes after 12 months of AOM treatment. METHODS: Seventy-five bipolar patients were recruited from 12 hospitals in Korea. We included 75 patients with BD who had received at least three AOM treatments from September 2019 to September 2022 and had accessible electronic medical record (EMRs) for the year before and after the baseline visit. RESULTS: The overall number of mood episodes significantly decreased from a mean of 1.5 ± 1.2 episodes pre-AOM to 0.5 ± 1.2 episodes post-AOM. Manic episodes significantly decreased from 0.8 ± 0.8 episodes pre-AOM to 0.2 ± 0.5 episodes post-AOM, and depressive episodes significantly decreased from 0.5 ± 0.8 episodes pre-AOM to 0.2 ± 0.6 episodes post-AOM (p = 0.017). Moreover, the number of psychiatric medications and pills and the proportion of patients treated with complex polypharmacy were significantly decreased post-AOM. LIMITATIONS: The small sample size was insufficient to fully represent the entire population of individuals with BD, and potential selection bias was introduced due to only including subjects who received AOM three or more times. CONCLUSION: The results of this study suggest that AOM can reduce mood episode relapse and may be clinically beneficial in the treatment of BD patients, potentially reducing issues associated with polypharmacy in some individuals.

Monolithic 3D integration of 2D materials-based electronics towards ultimate edge computing solutions.

Three-dimensional (3D) hetero-integration technology is poised to revolutionize the field of electronics by stacking functional layers vertically, thereby creating novel 3D circuity architectures with high integration density and unparalleled multifunctionality. However, the conventional 3D integration technique involves complex wafer processing and intricate interlayer wiring. Here we demonstrate monolithic 3D integration of two-dimensional, material-based artificial intelligence (AI)-processing hardware with ultimate integrability and multifunctionality. A total of six layers of transistor and memristor arrays were vertically integrated into a 3D nanosystem to perform AI tasks, by peeling and stacking of AI processing layers made from bottom-up synthesized two-dimensional materials. This fully monolithic-3D-integrated AI system substantially reduces processing time, voltage drops, latency and footprint due to its densely packed AI processing layers with dense interlayer connectivity. The successful demonstration of this monolithic-3D-integrated AI system will not only provide a material-level solution for hetero-integration of electronics, but also pave the way for unprecedented multifunctional computing hardware with ultimate parallelism.

Recent Advances and Future Prospects for Memristive Materials, Devices, and Systems.

Memristive technology has been rapidly emerging as a potential alternative to traditional CMOS technology, which is facing fundamental limitations in its development. Since oxide-based resistive switches were demonstrated as memristors in 2008, memristive devices have garnered significant attention due to their biomimetic memory properties, which promise to significantly improve power consumption in computing applications. Here, we provide a comprehensive overview of recent advances in memristive technology, including memristive devices, theory, algorithms, architectures, and systems. In addition, we discuss research directions for various applications of memristive technology including hardware accelerators for artificial intelligence, in-sensor computing, and probabilistic computing. Finally, we provide a forward-looking perspective on the future of memristive technology, outlining the challenges and opportunities for further research and innovation in this field. By providing an up-to-date overview of the state-of-the-art in memristive technology, this review aims to inform and inspire further research in this field.

Toward High-Performance Metal-Organic-Framework-Based Quasi-Solid-State Electrolytes: Tunable Structures and Electrochemical Properties.

Metal-organic frameworks (MOFs) have been reported as promising materials for electrochemical applications owing to their tunable porous structures and ion-sieving capability. However, it remains challenging to rationally design MOF-based electrolytes for high-energy lithium batteries. In this work, by combining advanced characterization and modeling tools, a series of nanocrystalline MOFs is designed, and the effects of pore apertures and open metal sites on ion-transport properties and electrochemical stability of MOF quasi-solid-state electrolytes are systematically studied. It isdemonstrated that MOFs with non-redox-active metal centers can lead to a much wider electrochemical stability window than those with redox-active centers. Furthermore, the pore aperture of MOFs is found to be a dominating factor that determines the uptake of lithium salt and thus ionic conductivity. The ab initio molecular dynamics simulations further demonstrate that open metal sites of MOFs can facilitate the dissociation of lithium salt and immobilize anions via Lewis acid-base interaction, leading to good lithium-ion mobility and high transference number. The MOF quasi-solid-state electrolyte demonstrates great battery performance with commercial LiFePO4 and LiCoO2 cathodes at 30 °C. This work provides new insights into structure-property relationships between tunable structure and electrochemical properties of MOFs that can lead to the development of advanced quasi-solid-state electrolytes for high-energy lithium batteries.

Vertical full-colour micro-LEDs via 2D materials-based layer transfer.

Micro-LEDs (µLEDs) have been explored for augmented and virtual reality display applications that require extremely high pixels per inch and luminance1,2. However, conventional manufacturing processes based on the lateral assembly of red, green and blue (RGB) µLEDs have limitations in enhancing pixel density3-6. Recent demonstrations of vertical µLED displays have attempted to address this issue by stacking freestanding RGB LED membranes and fabricating top-down7-14, but minimization of the lateral dimensions of stacked µLEDs has been difficult. Here we report full-colour, vertically stacked µLEDs that achieve, to our knowledge, the highest array density (5,100 pixels per inch) and the smallest size (4 µm) reported to date. This is enabled by a two-dimensional materials-based layer transfer technique15-18 that allows the growth of RGB LEDs of near-submicron thickness on two-dimensional material-coated substrates via remote or van der Waals epitaxy, mechanical release and stacking of LEDs, followed by top-down fabrication. The smallest-ever stack height of around 9 µm is the key enabler for record high µLED array density. We also demonstrate vertical integration of blue µLEDs with silicon membrane transistors for active matrix operation. These results establish routes to creating full-colour µLED displays for augmented and virtual reality, while also offering a generalizable platform for broader classes of three-dimensional integrated devices.

Unravelling the Complex LiOH-Based Cathode Chemistry in Lithium-Oxygen Batteries.

The LiOH-based cathode chemistry has demonstrated potential for high-energy Li-O2 batteries. However, the understanding of such complex chemistry remains incomplete. Herein, we use the combined experimental methods with ab initio calculations to study LiOH chemistry. We provide a unified reaction mechanism for LiOH formation during discharge via net 4 e- oxygen reduction, in which Li2 O2 acts as intermediate in low water-content electrolyte but LiHO2 as intermediate in high water-content electrolyte. Besides, LiOH decomposes via 1 e- oxidation during charge, generating surface-reactive hydroxyl species that degrade organic electrolytes and generate protons. These protons lead to early removal of LiOH, followed by a new high-potential charge plateau (1 e- water oxidation). At following cycles, these accumulated protons lead to a new high-potential discharge plateau, corresponding to water formation. Our findings shed light on understanding of 4 e- cathode chemistries in metal-air batteries.

Circularly polarized light-sensitive, hot electron transistor with chiral plasmonic nanoparticles.

The quantitative detection of circularly polarized light (CPL) is necessary in next-generation optical communication carrying high-density information and in phase-controlled displays exhibiting volumetric imaging. In the current technology, multiple pixels of different wavelengths and polarizers are required, inevitably resulting in high loss and low detection efficiency. Here, we demonstrate a highly efficient CPL-detecting transistor composed of chiral plasmonic nanoparticles with a high Khun's dissymmetry (g-factor) of 0.2 and a high mobility conducting oxide of InGaZnO. The device successfully distinguished the circular polarization state and displayed an unprecedented photoresponsivity of over 1 A/W under visible CPL excitation. This observation is mainly attributed to the hot electron generation in chiral plasmonic nanoparticles and to the effective collection of hot electrons in the oxide semiconducting transistor. Such characteristics further contribute to opto-neuromorphic operation and the artificial nervous system based on the device successfully performs image classification work. We anticipate that our strategy will aid in the rational design and fabrication of a high-performance CPL detector and opto-neuromorphic operation with a chiral plasmonic structure depending on the wavelength and circular polarization state.

Advances in Lithium-Oxygen Batteries Based on Lithium Hydroxide Formation and Decomposition.

The rechargeable lithium-oxygen (Li-O2) batteries have been considered one of the promising energy storage systems owing to their high theoretical energy density. As an alternative to Li-O2 batteries based on lithium peroxide (Li2O2) cathode, cycling Li-O2 batteries via the formation and decomposition of lithium hydroxide (LiOH) has demonstrated great potential for the development of practical Li-O2 batteries. However, the reversibility of LiOH-based cathode chemistry remains unclear at the fundamental level. Here, we review the recent advances made in Li-O2 batteries based on LiOH formation and decomposition, focusing on the reaction mechanisms occurring at the cathode, as well as the stability of Li anode and cathode binder. We also provide our perspectives on future research directions for high-performance, reversible Li-O2 batteries.

Vacuum-free solution-based metallization (VSM) of a-IGZO using trimethylaluminium solution.

This research demonstrates a method to reduce the resistance of amorphous indium-gallium-zinc-oxide (a-IGZO) using a "vacuum-free solution-based metallization" (VSM) process, which revolutionizes the metallization process thanks to its simplicity, by simply dipping the a-IGZO into trimethyl aluminium (TMA, (CH3)3Al) solution. From the XPS results, it was found that oxygen vacancies were generated after the VSM process, resulting in the enhanced conductivity. Various metallization time and solution temperature conditions were investigated, and the measured conductivity of the a-IGZO could be enhanced up to 20.32 S cm-1, which is over 105 times larger compared to that of the untreated a-IGZO. By utilizing the VSM process, self-aligned top-gate (SATG) a-IGZO thin-film-transistors (TFTs) were successfully fabricated, and to provide an explanation for the mechanism, X-ray photoelectron spectroscopy (XPS) was employed.

Comparing Internal and Interparticle Space Effects of Metal-Organic Frameworks on Polysulfide Migration in Lithium-Sulfur Batteries.

One of the critical issues hindering the commercialization of lithium-sulfur (Li-S) batteries is the dissolution and migration of soluble polysulfides in electrolyte, which is called the 'shuttle effect'. To address this issue, previous studies have focused on separators featuring specific chemical affinities or physical confinement by porous coating materials. However, there have been no studies on the complex effects of the simultaneous presence of the internal and interparticle spaces of porous materials in Li-S batteries. In this report, the stable Zr-based metal-organic frameworks (MOFs), UiO-66, have been used as a separator coating material to provide interparticle space via size-controlled MOF particles and thermodynamic internal space via amine functionality. The abundant interparticle space promoted mass transport, resulting in enhanced cycling performance. However, when amine functionalized UiO-66 was employed as the separator coating material, the initial specific capacity and capacity retention of Li-S batteries were superior to those materials based on the interparticle effect. Therefore, it is concluded that the thermodynamic interaction inside internal space is more important for preventing polysulfide migration than spatial condensation of the interparticle space.

In Situ Probing Potassium-Ion Intercalation-Induced Amorphization in Crystalline Iron Phosphate Cathode Materials.

Na-ion and K-ion batteries are promising alternatives for large-scale energy storage due to their abundance and low cost. Intercalation of these large ions could cause irreversible structural deformation and partial to complete amorphization in the crystalline electrodes. A lack of understanding of the dynamic changes in the amorphous nanostructure during battery operation is the bottleneck for further developments. Here, we report the utilization of in-operando digital image correlation and XRD techniques to probe dynamic changes in the amorphous phase of iron phosphate during potassium ion intercalation. In-operando XRD demonstrates amorphization in the electrode's nanostructure during the first charge and discharge cycle. Additionally, ex situ HR-TEM further confirms the amorphization after potassium-ion intercalation. An in situ strain analysis detects reversible deformations associated with redox reactions in the amorphous phases. Our approach offers new insights into the mechanism of ion intercalation in the amorphous nanostructure which are highly potent for the development of next-generation batteries.

Prognosis Score System to Predict Survival for COVID-19 Cases: a Korean Nationwide Cohort Study.

BACKGROUND: As the COVID-19 pandemic continues, an initial risk-adapted allocation is crucial for managing medical resources and providing intensive care. OBJECTIVE: In this study, we aimed to identify factors that predict the overall survival rate for COVID-19 cases and develop a COVID-19 prognosis score (COPS) system based on these factors. In addition, disease severity and the length of hospital stay for patients with COVID-19 were analyzed. METHODS: We retrospectively analyzed a nationwide cohort of laboratory-confirmed COVID-19 cases between January and April 2020 in Korea. The cohort was split randomly into a development cohort and a validation cohort with a 2:1 ratio. In the development cohort (n=3729), we tried to identify factors associated with overall survival and develop a scoring system to predict the overall survival rate by using parameters identified by the Cox proportional hazard regression model with bootstrapping methods. In the validation cohort (n=1865), we evaluated the prediction accuracy using the area under the receiver operating characteristic curve. The score of each variable in the COPS system was rounded off following the log-scaled conversion of the adjusted hazard ratio. RESULTS: Among the 5594 patients included in this analysis, 234 (4.2%) died after receiving a COVID-19 diagnosis. In the development cohort, six parameters were significantly related to poor overall survival: older age, dementia, chronic renal failure, dyspnea, mental disturbance, and absolute lymphocyte count <1000/mm3. The following risk groups were formed: low-risk (score 0-2), intermediate-risk (score 3), high-risk (score 4), and very high-risk (score 5-7) groups. The COPS system yielded an area under the curve value of 0.918 for predicting the 14-day survival rate and 0.896 for predicting the 28-day survival rate in the validation cohort. Using the COPS system, 28-day survival rates were discriminatively estimated at 99.8%, 95.4%, 82.3%, and 55.1% in the low-risk, intermediate-risk, high-risk, and very high-risk groups, respectively, of the total cohort (P<.001). The length of hospital stay and disease severity were directly associated with overall survival (P<.001), and the hospital stay duration was significantly longer among survivors (mean 26.1, SD 10.7 days) than among nonsurvivors (mean 15.6, SD 13.3 days). CONCLUSIONS: The newly developed predictive COPS system may assist in making risk-adapted decisions for the allocation of medical resources, including intensive care, during the COVID-19 pandemic.

Synaptic transistors based on a tyrosine-rich peptide for neuromorphic computing.

In this article, we propose an artificial synaptic device based on a proton-conducting peptide material. By using the redox-active property of tyrosine, the Tyr-Tyr-Ala-Cys-Ala-Tyr-Tyr peptide film was utilized as a gate insulator that shows synaptic plasticity owing to the formation of proton electric double layers. The ion gating effects on the transfer characteristics and temporal current responses are shown. Further, timing-dependent responses, including paired-pulse facilitation, synaptic potentiation, and transition from short-term plasticity to long-term plasticity, have been demonstrated for the electrical emulation of biological synapses in the human brain. Herein, we provide a novel material platform that is bio-inspired and biocompatible for use in brain-mimetic electronic devices.

Proton-enabled activation of peptide materials for biological bimodal memory.

The process of memory and learning in biological systems is multimodal, as several kinds of input signals cooperatively determine the weight of information transfer and storage. This study describes a peptide-based platform of materials and devices that can control the coupled conduction of protons and electrons and thus create distinct regions of synapse-like performance depending on the proton activity. We utilized tyrosine-rich peptide-based films and generalized our principles by demonstrating both memristor and synaptic devices. Interestingly, even memristive behavior can be controlled by both voltage and humidity inputs, learning and forgetting process in the device can be initiated and terminated by protons alone in peptide films. We believe that this work can help to understand the mechanism of biological memory and lay a foundation to realize a brain-like device based on ions and electrons.

Quantitative analysis of the coupling between proton and electron transport in peptide/manganese oxide hybrid films.

Understanding how electrons and protons move in a coupled manner and affect one another is important to the design of proton-electron conductors and achieving biological transport in synthetic materials. In this study, a new methodology is proposed that allows for the quantification of the degree of coupling between electrons and protons in tyrosine-rich peptides and metal oxide hybrid films at room temperature under a voltage bias. This approach is developed according to the Onsager principle, which has been thoroughly established for the investigation of mixed ion-electron conductors with electron and oxide ion vacancies as carriers at high temperatures. Herein, a new device platform using electron-blocking electrodes provides a new strategy to investigate the coupling of protons and electrons in bulk materials beyond the molecular level investigation of coupled proton and electron transfer. Two Onsager transport parameters, αi* and σe', are obtained from the device, and the results of these transport parameters demonstrate that the coupled transport of electrons and protons inside the hybrid film plays an important role in the macroscopic-scale conduction. The results suggest that an average of one electron is dragged by one proton in the absence of a direct driving force for electron movement ∇ηe.

Bone Mineral Density Around the Knee Joint: Correlation With Central Bone Mineral Density and Associated Factors.

INTRODUCTION: The aims of this study were to (1) assess the bone mineral density (BMD) around the knee joint, (2) determine the correlation between central and knee BMDs, and (3) investigate the factors associated with BMD around the knee joint in patients with knee osteoarthritis (OA). METHODOLOGY: This cross-sectional study included 122 patients who underwent total knee arthroplasty. Central and knee dual-energy X-ray absorptiometry was performed preoperatively. BMD at 6 regions of interest (ROIs) around the knee joint were measured, and their correlations with central BMD were determined using Spearman's correlation analysis. Lower limb alignment, severity of OA, body mass index (BMI), preoperative functional and pain scores were assessed to elucidate the factors associated with knee BMD using linear regression analysis. RESULTS: Around the knee joint, BMD was the lowest at the distal femoral metaphysis and lateral tibial condyle. Knee BMD was significantly correlated with central BMD. However, the correlation coefficients varied by the ROI. Additionally, multivariate analysis revealed different associations with respect to the regions around the knee joint. Varus alignment of the lower limb was associated with increased BMD of the medial condyles and decreased BMD of lateral condyles. High grade OA was a protective factor; it was associated with increased BMD at the lateral condyles of the femur and tibia. Higher BMI was an independent protective factor in all ROIs around the knee joint except the lateral femoral condyles. Lower functional level was not associated with decreased BMD, whereas a higher pain score was significantly associated with lower BMD at the proximal tibial metaphysis. CONCLUSIONS: Knee BMD was significantly correlated with central BMD. However, the correlations varied with the regions around the knee joint probably due to their independent association with the alignment of the lower limb, severity of OA, BMI, and preoperative pain level.