bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copolymer‐Templated Nickel Oxide for High‐Efficiency Mesoscopic Perovskite Solar Cells in Inverted Architecture
Authors: Sadegh Faranak , Akin Seckin , Moghadam Majid , Keshavarzi Reza , Mirkhani Valiollah , Ruiz‐Preciado Marco A. , Akman Erdi , Zhang Hong , Amini Mina , Tangestaninejad Shahram , Mohammadpoor‐Baltork Iraj , Graetzel Michael , Hagfeldt Anders , Tress Wolfgang 
Published: June 2021

AbstractDespite the outstanding role of mesoscopic structures on the efficiency and stability of perovskite solar cells (PSCs) in the regular (n–i–p) architecture, mesoscopic PSCs in inverted (p–i–n) architecture have rarely been reported. Herein, an efficient and stable mesoscopic NiOx (mp‐NiOx) scaffold formed via a simple and low‐cost triblock copolymer template‐assisted strategy is employed, and this mp‐NiOx film is utilized as a hole transport layer (HTL) in PSCs, for the first time. Promisingly, this approach allows the fabrication of homogenous, crack‐free, and robust 150 nm thick mp‐NiOx HTLs through a facile chemical approach. Such a high‐quality templated mp‐NiOx structure promotes the growth of the perovskite film yielding better surface coverage and enlarged grains. These desired structural and morphological features effectively translate into improved charge extraction, accelerated charge transportation, and suppressed trap‐assisted recombination. Ultimately, a considerable efficiency of 20.2% is achieved with negligible hysteresis which is among the highest efficiencies for mp‐NiOx based inverted PSCs so far. Moreover, mesoscopic devices indicate higher long‐term stability under ambient conditions compared to planar devices. Overall, these results may set new benchmarks in terms of performance for mesoscopic inverted PSCs employing templated mp‐NiOx films as highly efficient, stable, and easy fabricated HTLs.
Activation of Self‐Trapped Emission in Stable Bismuth‐Halide Perovskite by Suppressing Strong Exciton–Phonon Coupling
Authors: Zhou Lei , Liao Jin‐Feng , Qin Youcheng , Wang Xu‐Dong , Wei Jun‐Hua , Li Ming , Kuang Dai‐Bin , He Rongxing 
Published: June 2021

AbstractAll‐inorganic bismuth‐halide perovskites are promising alternatives for lead halide perovskites due to their admirable chemical stability and optoelectronic properties; however, these materials deliver inferior photoluminescence (PL) properties, severely hindering their prospects in lighting applications. Here, a novel air‐stable but non‐emissive perovskite Rb3BiCl6 is synthesized, and the material is used as a prototype to uncover origin of the poor optical performance in bismuth‐halide perovskite. It is found that the extremely strong exciton–phonon interactions with a large coupling constant up to 693 meV leads to the seriously nonradiative recombination, which, however, can be effectively suppressed to 347 meV by introducing Sb3+ ions. As a result, Sb3+‐doped Rb3BiCl6 exhibits a stable yellow emission with unprecedented PL quantum yield up to 33.6% from self‐trapped excitons. Systematic spectroscopic characterizations and theoretical calculations are carried out to unveil the intriguing photophysical mechanisms. This work reveals the effect of exciton–phonon interaction, that is often underemphasized, on a material's photophysical properties.
Nanoscale Film Thickness Gradients Printed in Open Air by Spatially Varying Chemical Vapor Deposition
Authors: Alshehri Abdullah H. , Loke Jhi Yong , Nguyen Viet Huong , Jones Alexander , Asgarimoghaddam Hatameh , Delumeau Louis‐Vincent , Shahin Ahmed , Ibrahim Khaled H. , Mistry Kissan , Yavuz Mustafa , Muñoz‐Rojas David , Musselman Kevin P. 
Published: June 2021

AbstractNanoscale films are integral to all modern electronics. To optimize device performance, researchers vary the film thickness by making batches of devices, which is time‐consuming and produces experimental artifacts. Thin films with nanoscale thickness gradients that are rapidly deposited in open air for combinatorial and high‐throughput (CHT) studies are presented. Atmospheric pressure spatial atomic layer deposition reactor heads are used to produce spatially varying chemical vapor deposition rates on the order of angstroms per second. ZnO and Al2O3 films are printed with nm‐scale thickness gradients in as little as 45 s and CHT analysis of a metal‐insulator‐metal diode and perovskite solar cell is performed. By testing 360 Pt/Al2O3/Al diodes with 18 different Al2O3 thicknesses on one wafer, a thicker insulator layer (≈7.0 nm) is identified for optimal diode performance than reported previously. Al2O3 thin film encapsulation is deposited by atmospheric pressure chemical vapor deposition (AP‐CVD) on a perovskite solar cell stack for the first time and a convolutional neural network is developed to analyze the perovskite stability. The rapid nature of AP‐CVD enables thicker films to be deposited at a higher temperature than is practical with conventional methods. The CHT analysis shows enhanced stability for 70 nm encapsulation films.
Producing Silicon Carbide Micro and Nanostructures by Plasma‐Free Metal‐Assisted Chemical Etching
Authors: Michaels Julian A. , Janavicius Lukas , Wu Xihang , Chan Clarence , Huang Hsieh‐Chih , Namiki Shunya , Kim Munho , Sievers Dane , Li Xiuling 
Published: June 2021

AbstractSilicon carbide (SiC) is a wide bandgap third‐generation semiconductor well suited for harsh environment power electronics, micro and nano electromechanical systems, and emerging quantum technology by serving as hosts for quantum states via defect centers. The chemical inertness of SiC limits viable etching techniques to plasma‐based reactive ion etching methods; however, these could have significant undesirable effects for electronic and photonic devices. This paper presents a plasma‐free, open‐circuit, photo‐induced metal‐assisted chemical etch for fabricating micro and nanoscale features without the inherent high energy ion‐related surface damage. The method presented herein utilizes above bandgap ultraviolet light, patterned noble metal (Pt), and a solution consisting of an oxidant potassium persulfate (K2S2O8) and an acid, hydrofluoric acid, to spatially define the etching morphology. The parameter space is comprehensively explored to demonstrate the controllability and versatility of this technique to produce ordered arrays of micro and nanoscale SiC structures with porous or solid sidewalls, and to elucidate the etching mechanism.
Direct Integration of Strained‐Pt Catalysts into Proton‐Exchange‐Membrane Fuel Cells with Atomic Layer Deposition
Authors: Xu Shicheng , Wang Zhaoxuan , Dull Sam , Liu Yunzhi , Lee Dong Un , Lezama Pacheco Juan S. , Orazov Marat , Vullum Per Erik , Dadlani Anup Lal , Vinogradova Olga , Schindler Peter , Tam Qizhan , Schladt Thomas D. , Mueller Jonathan E. , Kirsch Sebastian , Huebner Gerold , Higgins Drew , Torgersen Jan , Viswanathan Venkatasubramanian , Jaramillo Thomas Francisco , Prinz Fritz B. 
Published: June 2021

AbstractThe design and fabrication of lattice‐strained platinum catalysts achieved by removing a soluble core from a platinum shell synthesized via atomic layer deposition, is reported. The remarkable catalytic performance for the oxygen reduction reaction (ORR), measured in both half‐cell and full‐cell configurations, is attributed to the observed lattice strain. By further optimizing the nanoparticle geometry and ionomer/carbon interactions, mass activity close to 0.8 A mgPt−1 @0.9 V iR‐free is achievable in the membrane electrode assembly. Nevertheless, active catalysts with high ORR activity do not necessarily lead to high performance in the high‐current‐density (HCD) region. More attention shall be directed toward HCD performance for enabling high‐power‐density hydrogen fuel cells.
Room‐Temperature Magnetic Field Effect on Excitonic Photoluminescence in Perovskite Nanocrystals
Authors: Zhang Kun , Zhao Jian , Hu Qingsong , Yang Sijie , Zhu Xixiang , Zhang Yaqi , Huang Ruiqin , Ma Yongfu , Wang Zhenxing , Ouyang Zhongwen , Han Junbo , Han Yibo , Tang Jiang , Tong Wei , Zhang Lei , Zhai Tianyou 
Published: June 2021

AbstractMagnetic‐field‐enhanced spin‐polarized electronic/optical properties in semiconductors are crucial for fabricating various spintronic devices. However, this spin polarization is governed by weak spin exchange interactions and easily randomized by thermal fluctuations; therefore, it is only produced at cryogenic temperatures, which severely limits the applications. Herein, a room‐temperature intrinsic magnetic field effect (MFE) on excitonic photoluminescence is achieved in CsPbX3:Mn (X = Cl, Br) perovskite nanocrystals. Through moderate Mn doping, the MFE is enhanced by exciton–Mn interactions, and through partial Br substitution, the MFE is stabilized at room temperature by exciton orbital ordering. The orbital ordering significantly enhances the g‐factor difference between electrons and holes, which is evidenced by a parallel orbit–orbit interaction among excitons generated by circular polarized laser excitation. This study provides a clear avenue for engineering spintronic materials based on orbital interactions in perovskites.
Interfacial Adhesion of Fully Transient, Mussel‐Inspired Hydrogels with Different Network Crosslink Modalities
Authors: Darby Daniel R. , Lai Erica , Holten‐Andersen Niels , Pham Jonathan T. 
Published: June 2021

AbstractIn fully transient, mussel‐inspired hydrogels, metal‐coordinate complexes form supramolecular crosslinks, which offer tunable viscoelastic properties and mechanical reversibility. The metal‐coordination complexation that comprises the crosslinks can take on tris‐, bis‐, mono‐, and free‐state modalities (3, 2, 1, or 0 ligands per ion, respectively). Although prior work has established relationships between network crosslinking and mechanical properties, the effect of crosslink and ligand modalities on gel‐surface adhesion is not well understood for fully transient hydrogels. Using glass and nickel‐coated spherical probes, the effect of network crosslinking modalities on the adhesive strength of hydrogels based on histidine‐Ni2+ and nitrodopamine‐Fe3+ ion crosslinks is investigated. Since crosslink modalities have a strong impact on the mechanical properties of the bulk network, it is first determined how adhesion relates to the mechanical properties, regardless of the distribution of crosslinking modalities and ligand type. It is ultimately found that the peak adhesive stress increases with decreasing percentage of ligands in tris‐crosslinks.
Metal–Organic Frameworks Materials for Capacitive Gas Sensors
Authors: Zhai Zhenyu , Zhang Xiuling , Hao Xiaoke , Niu Ben , Li Congju 
Published: June 2021

AbstractGas sensors have been widely used in detection of industrial gas leak, air quality detection, and medical diagnosis. Although some chemical sensors have been commercialized, there are still some challenges such as sensitivity, cycle stability, and high power consumption. Metal–organic frameworks (MOFs) have high specific surface area, rich porosity, and excellent reversible/selective adsorption ability for various gases. Therefore, MOFs has been considered as an ideal sensing material. Metal active sites and active functional groups on the surface of MOFs can combine with gas molecules through hydrogen bonds, van der Waals interactions, and electrostatic interactions, resulting in highly effective selectivity and superior cycle reversibility. Meanwhile, MOFs‐based capacitive gas sensor can respond at room temperature, which can largely reduce energy consumption during the test. Therefore, the application of MOFs materials in capacitive gas sensors can effectively solve the above problems. In this review, the latest studies on MOFs‐based capacitive gas sensors for acidic/alkaline, VOCs, and water are summarized, and research prospects based on the mechanism of MOFs as sensing layers and filtering layers are proposed.
Transparent Magnetic Soft Millirobot Actuated by Micro‐Node Array
Authors: Li Gen , Zhang Tieshan , Shen Yajing 
Published: June 2021

AbstractMagnetic soft millirobots have attracted emerging interest in many fields owing to their superiorities in effective and remote controllable actuation by a magnetic field. However, limited to the embedded magnetic particles, magnetic soft robots usually exhibit dark to black colors, leading to the sheltering of the environment and target during locomotion, manipulation, and transportation. Here, a method of constructing a transparent magnetic millirobot with an actuatable micro‐node array is presented. Owing to the micro‐node design and high‐transparency body materials, the robot can achieve a high transmittance of ≈80%. The robot possesses remote‐controllable locomotion and obstacle‐crossing capabilities, such as crawling through a limited area (height: 600 µm) and crossing over an obstacle (height: 1 mm) that is about five times higher than itself. Moreover, the robot demonstrates optical transparent property against the changing environment, such as chessboard and rainbow‐colored backgrounds. Lastly, the locomotion and camouflage capability of the robot are demonstrated on sand, where the robot moves 23 mm in 59 s on the irregular sandy surface. This design strategy can be broadened to a wide range of fields, including but not limited to robots for battlefield, biomedical treatment, and environmental reconnaissance, and will benefit the development of the next generation of smart robots.
Bio‐Inspired Artificial Vision and Neuromorphic Image Processing Devices
Authors: Kim Min Sung , Kim Min Seok , Lee Gil Ju , Sunwoo Sung‐Hyuk , Chang Sehui , Song Young Min , Kim Dae‐Hyeong 
Published: June 2021

AbstractRemarkable technological developments for efficient image recognition (i.e., image acquisition and image data processing) have been reported in the past decade. Such advances in imaging and image processing technologies have driven significant progress in mobile electronics and machine vision applications. In particular, for image acquisition devices, two types of natural eyes (i.e., chambered and compound eyes) have inspired the development of novel multifunctional imaging devices with unique optical geometries. For image data processing devices, novel computing devices based on memristor crossbar arrays, such as electronic synapses, have been developed. More recently, the integration of imaging and image processing devices in a single unit further enhances the system‐level efficiency. Herein, such recent advances in the bio‐inspired artificial vision and neuromorphic image processing devices, aimed at providing efficient image recognition, are reviewed. First, various imaging devices inspired by the structural and functional features of natural eyes are introduced. Second, artificial synapses and their operation principles are thoroughly discussed. Third, the neuromorphic vision sensor that integrates the imaging and image processing devices is reviewed. Finally, a brief summary and future outlook are presented.
Triboelectric Laminates with Volumetric Electromechanical Response for Mechanical Energy Harvesting
Authors: Šutka Andris , Mālnieks Kaspars , Linarts Artis , Lapčinskis Linards , Verners Osvalds , Timusk Martin 
Published: June 2021

AbstractThe main requirement for triboelectric nanogenerator devices is the necessity to have separable or movable parts to harvest mechanical energy, thus complicating their integration into the energy harvesting systems. Herein, triboelectric laminates that show a volumetric electromechanical response are introduced, similar to intrinsic ferroelectric polymers. The laminates are composed of stacked bilayer polymer films with different triboelectric surface properties separated by polymer mesh. This sophisticated design provides dipole alignment across the volume of triboelectric laminate and electromechanical response without applying any poling procedure. Triboelectric laminate generates the open‐circuit voltage (VOC) of 29 V and short‐circuit current (ISC) of 15 nA. Volumetric energy density of 21.13 µJ cm−3 and a peak average power density of 46.19 µW cm−3 are observed. Triboelectric laminate shows an effective piezoelectric constant d33 of 9.83 pC N−1, higher than reported for piezoelectric polymer like nylon‐11. The triboelectric laminate is produced from cheap, mechanically flexible materials that can be produced in large quantities.
Flexible and Transparent Metal Nanowire Microelectrode Arrays and Interconnects for Electrophysiology, Optogenetics, and Optical Mapping
Authors: Chen Zhiyuan , Boyajian Nicolas , Lin Zexu , Yin Rose T. , Obaid Sofian N. , Tian Jinbi , Brennan Jaclyn A. , Chen Sheena W. , Miniovich Alana N. , Lin Leqi , Qi Yarong , Liu Xitong , Efimov Igor R. , Lu Luyao 
Published: June 2021

AbstractTransparent microelectrodes have recently emerged as a promising approach for crosstalk‐free multifunctional electrical and optical biointerfacing. High‐performance flexible platforms that allow seamless integration with soft tissue systems for such applications are urgently needed. Here, silver nanowires (Ag NWs)‐based transparent microelectrode arrays (MEAs) and interconnects are designed to meet this demand. The nanowire networks exhibit a high optical transparency >90.0% at 550 nm, and superior mechanical stability up to 100,000 bending cycles at 5 mm radius. The Ag NWs microelectrodes preserve low normalized electrochemical impedance of 3.4–15 Ω cm2 at 1 kHz, and the interconnects demonstrate excellent sheet resistance (Rsh) of 4.1–25 Ω sq−1. In vivo histological analysis reveals that the Ag NWs structures are biocompatible. Studies on Langendorff‐perfused mouse and rat hearts demonstrate that the Ag NWs MEAs enable high‐fidelity real‐time monitoring of heart rhythm during co‐localized optogenetic pacing and optical mapping. This proof‐of‐concept work illustrates that the solution‐processed, transparent, and flexible Ag NWs structures are a promising candidate for the next‐generation of large‐area multifunctional biointerfaces for interrogating complex biological systems in basic and translational research.
Cobalt‐Catalyzed C−H Alkoxylation of Ferrocenes with Alcohols under Mild Conditions
Authors: Zhang Zhuo‐Zhuo , Cheng Jie , Yao Qi‐Jun , Yue Qiang , Zhou Gang 
Published: June 2021

AbstractHerein we reported a protocol for synthesis of oxy‐substituted ferrocenes via cobalt‐catalyzed direct C−H alkoxylation under mild conditions. Notably, alcohol serves as an both alkoxide reagent and a solvent. Various ferrocene amides including estrone‐derived ferrocene amide are compatible with these reaction conditions. Moreover, control experiments suggested that this alkoxylation might undergo a Co(III)/Co(IV)/Co(II) catalytic cycle.magnified image
Cytokines: From Clinical Significance to Quantification
Authors: Liu Chao , Chu Dewei , Kalantar‐Zadeh Kourosh , George Jacob , Young Howard A. , Liu Guozhen 
Published: June 2021

AbstractCytokines are critical mediators that oversee and regulate immune and inflammatory responses via complex networks and serve as biomarkers for many diseases. Quantification of cytokines has significant value in both clinical medicine and biology as the levels provide insights into physiological and pathological processes and can be used to aid diagnosis and treatment. Cytokines and their clinical significance are introduced from the perspective of their pro‐ and anti‐inflammatory effects. Factors affecting cytokines quantification in biological fluids, native levels in different body fluids, sample processing and storage conditions, sensitivity to freeze‐thaw, and soluble cytokine receptors are discussed. In addition, recent advances in in vitro and in vivo assays, biosensors based on different signal outputs and intracellular to extracellular protein expression are summarized. Various quantification platforms for high‐sensitivity and reliable measurement of cytokines in different scenarios are discussed, and commercially available cytokine assays are compared. A discussion of challenges in the development and advancement of technologies for cytokine quantification that aim to achieve real‐time multiplex cytokine analysis for point‐of‐care situations applicable for both biomedical research and clinical practice are discussed.
Insights into the Correlation between Tetragonal Phase and Temperature Stability of Potassium Sodium Niobate Based Ceramics from Domain Behaviors
Authors: Xue Haoyue , Zheng Ting , Wu Jiagang 
Published: June 2021

AbstractThe temperature stability of tetragonal phase, as an indispensable end component of polymorphic phase boundary in high performance potassium sodium niobate based ceramics, has been long‐term neglected. Aimed at resolving the most cutting‐edge challenges for the practical application of potassium sodium niobate (KNN)‐based ceramics, the association study between tetragonal phase and its temperature stability is focused upon, especially from a microscopic point of view. Here, four kinds of potassium sodium niobate based ceramics with orthorhombic, tetragonal, orthorhombic–tetragonal, and rhombohedral–orthorhombic–tetragonal phase boundaries are designed, and investigations from macro properties as well as the underlying domain behaviors are conducted to establish the relationship between phase structure and temperature stability. Polarization retention with aging time and domain dynamics under thermal excitation suggest that tetragonal phase is closely related to the temperature sensitivity because of their instable and fast back‐switching properties of the reoriented domains. It is believed that a new perspective in the future designing of temperature‐insensitive ceramics is put up.
Multifunctional Optoelectronic Random Access Memory Device Based on Surface‐Plasma‐Treated Inorganic Halide Perovskite
Authors: Liu Qi , Yue Wenjing , Li Yang , Wang Wenxiao , Xu Lei , Wang Yaqi , Gao Song , Zhang Chunwei , Kan Hao , Li Chao 
Published: June 2021

AbstractEmerging optoelectronic resistive random access memory (RRAM) devices, enabled by optoelectronic materials with excellent properties have considerable advantages in terms of crosstalk, power consumption, response speed, and highly improved storage and computing abilities of RRAM devices. However, optoelectronic RRAM devices exhibiting outstanding electrical as well as optoelectronic performances are seldom reported, which hinders the development of the corresponding data storage and computing devices. In this study, an optoelectronic RRAM device with excellent electrical and optoelectronic properties is constructed based on surface‐plasma‐treated inorganic halide perovskite. The proposed RRAM device shows light‐assisted multilevel resistance as well as excellent resistive switching (RS) behavior, such as a high ON/OFF ratio, stable endurance and retention time. Moreover, the ADDER function and logic operation (IMPLICATION and OR) are successfully implemented on the proposed device with aid of light. Additionally, it is shown that the perovskite can be grown on a flexible substrate, leading to a flexible RRAM device exhibiting stable RS behavior. The possible operating mechanism is elaborated based on the Ag atom conductive filament model with assistance of density functional theory calculations. This proposed high‐performance multifunctional optoelectronic RRAM device undoubtedly shows broad possibilities for developing high‐density storage, in‐computing, flexible and transient memory devices.