bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Observation of Oxygen Ion Dynamics in a WO3‐x based Second‐Order Memristor with Dendritic Integration Functions
Authors: Lin Ya , Meng Fanqi , Zeng Tao , Zhang Qinghua , Wang Zhongqiang , Cheng Yankun , Zhao Xiaoning , Gu Lin , Xu Haiyang , Liu Yichun 
Published: May 2023

AbstractDirect observation of oxygen dynamics in an oxide‐based second‐order memristor can provide the valid evidence to clarify the memristive mechanism, however, which is still limited for now. In this study, the migration and diffusion of oxygen ions in the region of Pt/WO3‐x Schottky interface are observed in the WO3‐x second‐order memristor by using the technique of in situ transmission electron microscopy (TEM) and the electron energy loss spectroscopy. Interestingly, the coexistence of memristive and memcapacitive switching can be implemented in this memristor. Combined with the analysis of depth‐profile X‐ray photoelectron spectroscopy (XPS), an interface‐barrier‐modulation second‐order memristive model is proposed based on the above results. Notably, temporally correlative oxygen dynamics in the memristor offers the platform to integrate signals from multiple inputs, enabling the realization of the dendritic functions of synchronous and asynchronous integration for the application of logic operations with fault‐tolerance capability and associative learning. These findings provide the experimental evidence to in‐depth understanding of oxygen dynamics and switching mechanism in second‐order memristor, which can support the optimization of memristive performance and the achievement of biorealistic synaptic functions.
In Situ Reprogrammings of Splenic CD11b+ Cells by Nano‐Hypoxia to Promote Inflamed Damage Site‐Specific Angiogenesis
Authors: Chung Seyong , Kim Si Yeong , Lee Kyubae , Baek Sewoom , Ha Hyun‐Su , Kim Dae‐Hyun , Park Suji , Lee Chan Hee , Kim Hye‐Seon , Shin Young Min , Yu Seung Eun , Sung Hak‐Joon 
Published: May 2023

AbstractClinical translation of nanoparticles is limited because of their short circulation time, which hampers targeting to prolong therapeutic effects. Angiogenesis is required to regenerate damaged sites under inflammation, and CD11b+ cells turn vasculogenic under hypoxia. As a turning‐point strategy to increase the circulation time, this study explores liposomal targeting of splenic CD11b+ cells, which are gathered in the spleen and move to inflamed sites inherently. Moreover, nano‐hypoxia is strategized as a therapeutic method by loading liposomes with a hypoxic‐mimetic agent (CoCl2) to induce in situ reprogramming of splenic CD11b+ cells upon venous injection. Consequently, the vasculogenic potential of reprogrammed cells accelerates regeneration through inflammation‐responsive homing. Hydrophilic coating of liposomes improves the selectivity of splenic targeting in contrast to fast targeting without coating. Hypoxia chambers and surgical induction of splenic hypoxia are compared to validate the reprogramming effect. The strategy is validated in mouse models of inflamed skin, ischemic hindlimbs, and 70% hepatectomy compared with a conventional approach using bone marrow cells. Intravital multiphoton microscopy, 19F 2D/3D MRI, and microchannel hydrogel chips for 3D tissue culture are used as advanced tools. Overall, nanocarrier change to CD11b+ cells prolong targeting by inducing in situ reprogramming for inflammation‐responsive vasculogenic therapy.
Improving the Performance of Layer‐by‐Layer Processed Organic Solar Cells via Introducing a Wide‐Bandgap Dopant into the Upper Acceptor Layer
Authors: Chen Qiaoling , Huang Hao , Hu Di , Zhang Cai'e , Xu Xinjun , Lu Hao , Wu Yonggang , Yang Chuluo , Bo Zhishan 
Published: May 2023

AbstractThe layer‐by‐layer (LbL) solution‐processed organic solar cells (OSCs) are conductive to achieve vertical phase separation, tunable donor–acceptor (D/A) interfaces, and favorable charge‐transport pathways. In this work, a wide‐bandgap component poly(9‐vinylcarbazole) (PVK) is added to the upper electron acceptor layer to improve the performance of LbL‐processed OSCs. Results show that the PVK component can adjust the film morphology, dope the electron acceptor, increase the electron concentration, and improve charge transport. Such n‐type doping is verified by Seebeck coefficient measurement, ultraviolet photoelectron spectroscopy, and electron paramagnetic resonance characterization. In addition, the fluorescence intensity and exciton lifetime of the PVK‐doped acceptor film are increased, thus being beneficial for exciton diffusion to the D/A interface. Therefore, the power conversion efficiency (PCE) of LbL OSCs increases when 2.50 wt.% PVK is employed in the electron acceptor layer of commonly‐used high‐efficiency system and a maximum value of 19.05% can be achieved. The role of PVK played in the active layer is different from those of additives and ternary components reported previously, so the results provide an alternative way to enhance the device performance of LbL‐processed OSCs.
Multiwavelength Achromatic Metalens in Visible by Inverse Design
Authors: Jiang Qiang , Liu Jianghong , Li Junyi , Jing Xiaoli , Li Xin , Huang Lingling , Wang Yongtian 
Published: May 2023

AbstractAchromatic metalenses are promising alternatives to traditional lenses, allowing the miniaturization of optical systems. However, the limitation due to the group delay range of the meta‐atoms that can be fabricated requires a trade‐off relationship between the working bandwidth, numerical aperture (NA), and aperture of the achromatic metalens operating in a continuous spectrum. Considering that light sources used in most optical systems to illuminate or display images in most optical systems generate multiwavelength light with a narrow bandwidth, an efficient end‐to‐end inverse design framework for multiwavelength achromatic metalenses is implemented. As a proof of concept, an achromatic metalens with an NA of 0.3 and a diameter of 115 µm at four visible wavelengths and arbitrary linear polarization is designed and experimentally demonstrated. The measured results show a maximum focal length shift of 5.2778%. The proposed strategy avoids complicated physical models, enabling the integration of complex functionalities into a single metasurface, thereby driving the design of efficient and emerging devices.
High‐Efficiency and Narrow‐Band Near‐Ultraviolet Emitters with Low CIEy of 0.03 by Incorporating Extra Weak Charge Transfer Channel into Multi‐Resonance Skeleton
Authors: Gan Xiang‐Qin , Ding Zhen‐Ming , Liu Deng‐Hui , Zheng Wei‐Qiong , Ma Bin , Zhang Hu , Chang Xiang , Wang Li , Liu Yu , Wu Xiugang , Su Shi‐Jian , Zhu Weiguo 
Published: May 2023

AbstractHybridized local and charge‐transfer (HLCT) excited‐state emitters can effectively utilize non‐radiative triplet excitons through high‐lying reverse intersystem crossing (hRISC), but they are mostly limited to the donor‐π‐acceptor type molecules. It is a great challenge to develop high‐performance near‐ultraviolet (NUV) emitters with narrow‐band emission by HLCT due to the large carrier injection barriers and high triplet energy. In this work, by incorporating planar multi‐resonance (MR) skeleton of oxygen‐bridged triphenylborane (BO) and weak electron‐donating unit of tetraphenyl‐silane (TPS), two NUV emitters of tBOSi and tBOSiCz are developed, where an extra weak charge transfer (CT) channel between BO skeleton and peripheral phenyl in TPS is observed to increase CT component and activate hot exciton channel of hRISC. As a result, tBOSi and tBOSiCz show an outstanding narrow‐band NUV emission at 414 nm with a FWHM of about 32 nm in solution‐processed organic light‐emitting diodes (OLEDs), even at a heavy doping ratio. The best NUV electroluminescent properties are further achieved in the optimal tBOSi‐doped OLEDs with a record efficiency of 9.15% and a low CIEy of 0.034. This work provides a profound guidance for developing high‐performance narrow‐band NUV emitters by an extra weak CT channel into MR skeleton to activate HLCT emission.
Hydrogel Lasers Via Supramolecular Host–Guest Complexation
Authors: Paatelainen Matias , Lahikainen Markus , Berdin Alex , Kuntze Kim , Nau Werner M. , Nonappa  , Priimagi Arri 
Published: May 2023

AbstractSupramolecular host–guest complexes are dynamic systems composed of typically macrocyclic host molecules encapsulating smaller guest molecules. One of their applications is the selective encapsulation of fluorescent dye molecules to tackle quenching and photobleaching in solution. When extended to solid matrices, the efficiency of dyes can be especially poor, limiting their use in fluorescence‐based applications. Here it is demonstrated that supramolecular host–guest complexation in a hydrogel network allows readily tunable hydrogel‐based lasers. Poly(N‐isopropylacrylamide)‐based copolymer hydrogel is used with covalently linked Rhodamine B molecules. By controlled doping of cucurbit[7]uril as a host molecule in the hydrogel, it is shown that the fluorescent quantum yield increases from 17% to 51%, accompanied by 15‐fold enhancement in photostability. As proof of concept, a thin‐film distributed feedback hydrogel laser with wavelength tunability is fabricated. The results reveal a 30% increase in slope efficiency in the presence of host molecules. These results, combined with the inherent stimuli‐response of hydrogels, enable new possibilities for affordable and small‐scale photonic devices capable of safely interacting with the environment in, for example, sensing applications.
Photocatalytic Cascade Reaction Driven by Directed Charge Transfer over VS‐Zn0.5Cd0.5S/GO for Controllable Benzyl Oxidation
Authors: Bai Xue , She Mengyao , Ji Yali , Zhang Zhe , Xue Wenhua , Liu Enzhou , Wan Kerou , Liu Ping , Zhang Shengyong , Li Jianli 
Published: May 2023

AbstractPhotocatalysis is an important technique for synthetic transformations. However, little attention has been paid to light‐driven synergistic redox reactions for directed synthesis. Herein, the authors report tunable oxidation of benzyl to phenylcarbinol with the modest yield (47%) in 5 h via singlet oxygen (1O2) and proton‐coupled electron transfer (PCET) over the photocatalyst Zn0.5Cd0.5S (ZCS)/graphene oxide (GO) under exceptionally mild conditions. Theoretical calculations indicate that the presence of S vacancies on the surface of ZCS/GO photocatalyst is crucial for the adsorption and activation of O2, successively generating the superoxide radical (•O2−) and 1O2, attributing to the regulation of local electron density on the surface of ZCS/GO and photogenerated holes (h+). Meanwhile, accelerated transfer of photogenerated electrons (e−) to GO caused by the π–π stacking effect is conducive to the subsequent aldehyde hydrogenation to benzyl alcohol rather than non‐selective oxidation of aldehyde to carboxylic acid. Anisotropic charge transport driven by the built‐in electric field can further promote the separation of e− and h+ for multistep reactions. Promisingly, one‐pot photocatalytic conversion of p‐xylene to 4‐methylbenzyl alcohol is beneficial for reducing the harmful effects of aromatics on human health. Furthermore, this study provides novel insights into the design of photocatalysts for cascade reactions.
Stitching Flexible Electronics into the Brain
Authors: Lee Jung Min , Lin Dingchang , Pyo Young‐Woo , Kim Ha‐Reem , Park Hong‐Gyu , Lieber Charles M. 
Published: May 2023

AbstractUnderstanding complex neuronal networks requires monitoring long‐term neuronal activity in various regions of the brain. Significant progress has been made in multisite implantations of well‐designed probes, such as multisite implantation of Si‐based and polymer‐based probes. However, these multiprobe strategies are limited by the sizes and weights of interfaces to the multiple probes and the inability to track the activity of the same neurons and changes in neuronal activity over longer time periods. Here, a long single flexible probe that can be implanted by stitching into multiple regions of the mouse brain and subsequently transmit chronically stable neuronal signals from the multiple sites via a single low‐mass interface is reported. The probe at four different sites is implemented using a glass capillary needle or two sites using an ultrathin metal needle. In vitro tests in brain‐mimicking hydrogel show that multisite probe implantations achieve a high connection yield of >86%. In vivo histological images at each site of probes, implanted by stitching using either glass capillary or ultrathin metal insertion needles exhibit seamless tissue–probe interfaces with negligible chronic immune response. In addition, electrophysiology studies demonstrate the ability to track single neuron activities at every injection site with chronic stability over at least one month. Notably, the measured spike amplitudes and signal‐to‐noise ratios at different implantation sites show no statistically significant differences. Multisite stitching implantation of flexible electronics in the brain opens up new opportunities for both fundamental neuroscience research and electrotherapeutic applications.
Electronic Tuning of CO2 Interaction by Oriented Coordination of N‐Rich Auxiliary in Porphyrin Metal–Organic Frameworks for Light‐Assisted CO2 Electroreduction
Authors: Xin Zhifeng , Dong Xue , Wang Yi‐Rong , Wang Qian , Shen Kejing , Shi Jing‐Wen , Chen Yifa , Lan Ya‐Qian 
Published: May 2023

AbstractThe efficient CO2 electroreduction into high‐value products largely relies on the CO2 adsorption/activation or electron‐transfer of electrocatalysts, thus site‐specific functionalization methods that enable boosted related interactions of electrocatalysts are much desired. Here, an oriented coordination strategy is reported to introduce N‐rich auxiliary (i.e., hexamethylenetetramine, HMTA) into metalloporphyrin metal organic frameworks (MOFs) to synthesize a series of site‐specific functionalized electrocatalysts (HMTA@MOF‐545‐M, M = Fe, Co, and Ni) and they are successfully applied in light‐assisted CO2 electroreduction. Noteworthy, thus‐obtained HMTA@MOF‐545‐Co presents approximately two times enhanced CO2 adsorption‐enthalpy and electrochemical active surface‐area with largely decreased impedance‐value after modification, resulting in almost twice higher CO2 electroreduction performance than its unmodified counterpart. Besides, its CO2 electroreduction performance can be further improved under light‐illumination and displays superior FECO (≈100%), high CO generation rate (≈5.11 mol m−2 h−1 at −1.1 V) and energy efficiency (≈70% at −0.7 V). Theoretical calculations verify that the oriented coordination of HMTA can increase the charge density of active sites, almost doubly enhance the CO2 adsorption energy, and largely reduce the energy barrier of rate determining step for the boosted performance improvement. This work might promote the development of modifiable porous crystalline electrocatalysts in high‐efficiency CO2 electroreduction.
Ultraflexible Organic Active Matrix Sensor Sheet for Tactile and Biosignal Monitoring
Authors: Karner‐Petritz Esther , Petritz Andreas , Uemura Takafumi , Namba Naoko , Araki Teppei , Sekitani Tsuyoshi , Stadlober Barbara 
Published: May 2023

AbstractFlexible sensors are currently the subject of intensive research, as they allow cost‐effective and environmentally friendly production of large‐area, flexible, and when fabricated on ultrathin substrates, highly conformable devices. Among many intriguing applications, tactile and biosignal monitoring, where lightweight sensors with high wearing comfort are particularly interesting, is focused on here. The required spatiotemporal resolution of the signals is achieved by integrating the sensors in an active matrix configuration. Organic ferroelectric transducers of high uniformity, characterized, for example, by a sensitivity spread of only 1.5%, are combined with similarly uniform ultralow noise level organic thin film transistors operating below 5 V, showing, for example, a threshold voltage variation of just 0.13 V, in a 12 × 12 sensor array. The transistors transition frequency of up to 160 kHz (saturation range) and 17 kHz (linear range) allows for a high spatiotemporal resolution of ≈3 mm at a frame rate of 1400 fps. The thickness of only 2.8 µm renders the organic active matrix sensor sheet ultraflexible and therefore virtually imperceptible on the human skin. Real‐time monitoring of tactile modes in a subset of 8 × 3 pixels and of the pulse wave including heart rate and blood pressure using four sensors of the matrix is demonstrated.
A Competitive n‐Type OECT Material via Copolymerization of Electron Deficient Building Blocks
Authors: Erhardt Andreas , Hochgesang Adrian , McNeill Christopher R. , Thelakkat Mukundan 
Published: May 2023

AbstractThe classical acceptor motifs diketopyrrolopyrrole (DPP) and thienopyrrolodione (TPD) are copolymerized to yield the acceptor–acceptor polymer “Poly(DPP‐TPD).” The fundamental design idea is to maximize the electron affinity (EA), thus increasing the ambient stability of the reduced state against oxygen and water while ensuring high ion compatibility through the incorporation of hydrophilic oligoethylene glycol N‐substituents. Additionally, a highly planarized polymer structure is anticipated, due to the extended noncovalent interactions (conformational locking) between the carbonyl oxygen and the thiophene protons. Cyclic voltammetry, spectroelectrochemistry, ultraviolet photoelectron spectroscopy, ultraviolet‐visible absorption spectroscopy, and organic field effect transistor (OFET) characterization demonstrate the suitability for n‐type organic electrochemical transistor (OECT) devices. High EA, ionization potential, and good electron mobility (µe(OFET)) are shown, in addition to the electrochemical reduction of polymer films in aqueous electrolyte. In n‐type OECTs, poly(DPP‐TPD) demonstrates a moderate threshold voltage of Vth = 0.58 V and an outstanding µC* value of 7.62 F cm−1 V−1 s−1. Cycling studies consisting of pulsed on‐ and off‐switching of the device at gate voltages between Vg = 0.6–0.8 V in the saturation regime reveal high stability for more than 2700 cycles with rapid switching kinetics.
Multi‐Dimensional Characterization of Battery Materials
Authors: Ziesche Ralf F. , Heenan Thomas M. M. , Kumari Pooja , Williams Jarrod , Li Weiqun , Curd Matthew E. , Burnett Timothy L. , Robinson Ian , Brett Dan J. L. , Ehrhardt Matthias J. , Quinn Paul D. , Mehdi Layla B. , Withers Philip J. , Britton Melanie M. , Browning Nigel D. , Shearing Paul R. 
Published: May 2023

AbstractDemand for low carbon energy storage has highlighted the importance of imaging techniques for the characterization of electrode microstructures to determine key parameters associated with battery manufacture, operation, degradation, and failure both for next generation lithium and other novel battery systems. Here, recent progress and literature highlights from magnetic resonance, neutron, X‐ray, focused ion beam, scanning and transmission electron microscopy are summarized. Two major trends are identified: First, the use of multi‐modal microscopy in a correlative fashion, providing contrast modes spanning length‐ and time‐scales, and second, the application of machine learning to guide data collection and analysis, recognizing the role of these tools in evaluating large data streams from increasingly sophisticated imaging experiments.
Ultrahigh‐Capacity Rocksalt Cathodes Enabled by Cycling‐Activated Structural Changes
Authors: Ahn Juhyeon , Giovine Raynald , Wu Vincent C. , Koirala Krishna Prasad , Wang Chongmin , Clément Raphaële J. , Chen Guoying 
Published: May 2023

AbstractMn‐redox‐based oxides and oxyfluorides are considered the most promising earth‐abundant high‐energy cathode materials for next‐generation lithium‐ion batteries. While high capacities are obtained in high‐Mn content cathodes such as Li‐ and Mn‐rich layered and spinel‐type materials, local structure changes and structural distortions ( often lead to voltage fade, capacity decay, and impedance rise, resulting in unacceptable electrochemical performance upon cycling. In the present study, structural transformations that exploit the high capacity of Mn‐rich oxyfluorides while enabling stable cycling, in stark contrast to commonly observed structural changes that result in rapid performance degradation, are reported. It is shown that upon cycling of a cation‐disordered rocksalt (DRX) cathode (Li1.1Mn0.8Ti0.1O1.9F0.1, an ultrahigh capacity of ≈320 mAh g−1 (energy density of ≈900 Wh kg−1) can be obtained through dynamic structural rearrangements upon cycling , along with a unique voltage profile evolution and capacity rise. At high voltage, the presence of Mn4+ and Li+ vacancies promotes local cation ordering, leading to the formation of domains of a “δ phase” within the disordered framework. On deep discharge, Mn4+ reduction, along with Li+ insertion transform the structure to a partially ordered DRX phase with a β′‐LiFeO2‐type arrangement. At the nanoscale, domains of the in situ formed phases are randomly oriented, allowing highly reversible structural changes and stable electrochemical cycling. These new insights not only help explain the superior electrochemical performance of high‐Mn DRXbut also provide guidance for the future development of Mn‐based, high‐energy density oxide, and oxyfluoride cathode materials.
High Fill Factor CsPbI2Br Perovskite Solar Cells Via Crystallization Management
Authors: Jeong Min Ju , Jeon Soo Woong , Kim Sung Yong , Noh Jun Hong 
Published: May 2023

AbstractInorganic CsPbI2Br perovskite has a substantial potential for triple‐junction tandem solar cells as a top subcell, however it exhibits relative instability in the air compared with organic‐inorganic perovskites as well as significantly lower efficiency than the theoretical efficiency limit. To further enhance the air‐stability and efficiency of CsPbI2Br‐based perovskite solar cells (PSCs), it is vitally crucial to improve the crystallinity and passivate the defects within films that accelerate the phase transformation to the photo‐inactive phase in the air. Here, it is reported that crystallization management via incorporating sodium formate (NaFo) in a CsPbI2Br perovskite solution effectively leads to enlarged grain size and the reduced trap density. The Na+ cation and HOOC− anion produce a synergistic effect for engineering the defects by acting as cation and pseudo‐halide anion passivators, respectively. As a result, the NaFo‐incorporating device shows an improved power conversion efficiency (PCE) of 17.7% with a fill factor (FF) of 84.5%. To the best of the authors' knowledge, this progressive FF value is the highest value among CsPbI2Br‐based PSCs reported thus far. In addition, the NaFo‐incorporated device shows improved air stability compared to the control device, retaining over 95% of its initial PCE for 1000 hours under 10% relative humidity at room temperature without any encapsulation.