bluuebunny/crossref_metadata_2025 huggingface dataset:
A Sustainable Self‐Induced Solution Seeding Approach for Multipurpose BiFeO3 Active Layers in Flexible Electronic Devices
Authors: Barrios Óscar , Jiménez Ricardo , Ricote Jesús , Tartaj Pedro , Calzada María Lourdes , Bretos Íñigo
Published: April 2022

The direct integration of crystalline oxide layers into flexible electronic systems requires the development of relatively simple, low‐temperature processing routes. Seeding represents a powerful strategy to reach this objective by the generation of preferential sites for the nucleation of crystalline phases with a reduced energy barrier. Here, a novel approach is reported where nanoseeds are generated in situ from a precursor solution using a solvent‐engineering strategy (solvent‐antisolvent). The controlled addition of an antisolvent (1,3‐propanediol) to a solution of metal salts (Bi/Fe) dissolved in acetic acid results in the formation of nanocrystals (seeds) by supersaturation. The presence of such nanoseeds is also confirmed in the deposited layers, improving significantly the crystallinity of the respective BiFeO3 thin films as complementary, deduced by piezoresponse force microscopy. Using this low‐temperature strategy, crystalline films are directly grown on flexible polymeric substrates at only 350 °C showing a remanent polarization of 10.5 µC cm−2 and a clear photovoltaic effect (11.7 µW cm−2) of interest in computer memories and energy harvesters. The flexibility of the BiFeO3 thin films may enlarge the number of applications of this multifunctional, lead‐free material in next‐generation digital and sustainable electronic devices based on a facile, low‐cost fabrication method with reduced energy consumption.
Silica‐Coated Gold Nanorod Supraparticles: A Tunable Platform for Surface Enhanced Raman Spectroscopy
Authors: van der Hoeven Jessi E.S. , Gurunarayanan Harith , Bransen Maarten , de Winter D.A. Matthijs , de Jongh Petra E. , van Blaaderen Alfons
Published: April 2022

Plasmonic nanoparticle assemblies are promising functional materials for surface‐enhanced Raman spectroscopy (SERS). Gold nanorod (AuNR) assemblies are of particular interest due to the large, shape‐induced local field enhancement and the tunable surface plasmon resonance of the AuNRs. Designing the optimal assembly structure for SERS, however, is challenging and requires a delicate balance between the interparticle distance, porosity, and wetting of the assembly. Here, a new type of functional assemblies–called supraparticles–fabricated through the solvent‐evaporation driven assembly of silica‐coated gold nanorods into spherical ensembles, in which the plasmonic coupling and the mass transport is tuned through the thickness and porosity of the silica shells are introduced. Etching of the AuNRs allowed fine‐tuning of the plasmonic response to the laser excitation wavelength. Using a correlative SERS‐electron microscopy approach, it is shown that all supraparticles successfully amplified the Raman signal of the crystal violet probe molecules, and that the Raman signal strongly increased when decreasing the silica shell thickness from 35 to 3 nm, provided that the supraparticles have a sufficiently high porosity. The supraparticles introduced in this study present a novel class of materials for sensing, and open up a wide parameter space to optimize their performance.
Engineering Densely Packed Adipose Tissue via Environmentally Controlled In‐Bath 3D Bioprinting
Authors: Ahn Minjun , Cho Won‐Woo , Kim Byoung Soo , Cho Dong‐Woo
Published: April 2022

The adipose tissue is a crucial endocrine organ that coordinates with other organs, playing a key role in metabolic regulation. However, it remains challenging to recreate the morphology of native adipose tissue with fully packed adipogenic lipid droplets, mainly because of immature adipogenesis caused by the low cell density of current adipose constructs. This study suggests environmentally controlled in‐bath 3D bioprinting to create fully‐mature densely packed adipose tissue (DPAT) in vitro. As a bath suspension, a hybrid bioink composed of 1% alginate and 1.5% adipose‐derived decellularized matrix is developed for selective and compact cell proliferation. In the hybrid bath suspension, the construct printed at a high cell density (>107 cells ml−1) proliferates within the predefined area without unwanted cell migration throughout the bath suspension, forming a densely packed cellular microenvironment. After adipogenesis for 4 weeks, the results demonstrate that selectively proliferated preadipocytes can differentiate into lipid‐accumulating mature adipocytes. The resulting in vivo‐like DPAT is successfully engineered in vitro. The DPAT construct shows the physiological changes associated with obesity under the relevant conditions found in obese patients. The recapitulation of obesity‐induced inflamed adipose tissue through co‐culture with monocytes reveals the potency of the proposed strategy as a promising solution to overcome obesity‐related complications.
Toward Direct Growth of Ultra‐Flat Graphene
Authors: Jiang Bei , Liang Dongdong , Sun Zhongti , Ci Haina , Liu Bingzhi , Gao Yaqi , Shan Jingyuan , Yang Xiaoqin , Rümmeli Mark H. , Wang Junxi , Wei Tongbo , Sun Jingyu , Liu Zhongfan
Published: April 2022

The elimination of wrinkles has become a research hotspot in the realm of the chemical vapor deposition growth of graphene, and there have been reliable routes developed for the scenario of catalytic synthesis on metals. Nonetheless, the transfer‐free growth of graphene over insulating substrates affording ultra‐flatness remains a puzzle. Here, the authors report the direct preparation of ultra‐flat graphene on an economical quartz glass substrate at a wafer level, without any wrinkles and metallic impurities, is reported. Density functional theory calculations are employed to establish that graphene adlayer is prone to generate in the presence of textured particulates. In parallel, a critical temperature regime (1443–1453 K), is identified within which graphene adlayer‐restrained forming and substrate in‐situ flattening could simultaneously occur. The thus‐obtained graphene enables the atomically smooth growth of a GaN film with (001) single‐crystallinity over the amorphous substrate. This technique is particularly attractive in the context of cost‐effective integration of emerging III‐nitrides toward exciting applications.
Manipulating Polymer Configuration to Accelerate Cation Intercalation Kinetics for High‐Performance Aqueous Zinc‐Ion Batteries
Authors: Wang Xinlei , Tang Jian , Tang Weihua
Published: April 2022

Aqueous zinc‐ion batteries (ZIBs) with safety and cost superiority are becoming promising for energy storage; meanwhile, organic electrodes are attracting considerable interest. The development of organic ZIBs lies in the solution of challenging issues on impeded Zn2+ interfacial diffusion and the corresponding sluggish reaction kinetics. Herein, triquinoxalinylene (3Q) based homopolymer (P3Q) and triazine‐linked 3Q polymer (P3Q‐t) with enlarged conjugated planes are designed and prepared to reveal the impact of molecular configuration on Zn2+ transfer and coordination dynamics. Their ZIB performance and ion intercalation mechanism are systematically investigated by structural characterization, electrochemical measurement, and theoretical calculation. Specifically, P3Q shows interactions with both Zn2+ and H+, while P3Q‐t is discovered to selectively coordinate only with Zn2+. Moreover, P3Q‐t exhibits high conjugated planarity and electronegative fused‐rings pathways due to both intermolecular and intramolecular effects, leading to faster reaction dynamics and low Zn2+ transfer resistance. P3Q‐t affords a high capacity of 237 mAh g–1 at 0.3 A g–1. More importantly, such capacity can be retained for 45% at 15 A g–1 and an average 81% of capacity retention is achieved over 1500 cycles.
Improved Low‐Temperature Performance of Rocking‐Chair Sodium‐Ion Hybrid Capacitor by Mitigating the De‐Solvation Energy and Interphase Resistance
Authors: Yang Jinyu , Ruan Jiafeng , Li Qin , Fang Fang , Song Yun , Sun Dalin , Wang Fei
Published: April 2022

Hybrid capacitors, which bear the advantages of secondary batteries and supercapacitors, can deliver high power with a relatively fair amount of energy. However, its kinetic performance, especially at low temperatures, is strongly limited by the battery‐type electrode and electrolyte. In this work, Na‐ion, which has a lower solvation energy than Li‐ion, is chosen as the charge carrier to build the hybrid capacitor. A sodium‐ion hybrid capacitor is built with an activated carbon cathode and a pre‐sodiated hard carbon anode. To achieve a better kinetic performance, the de‐solvation energy and interphase resistance is decreased through replacing conventional carbonate electrolyte with a diethylene glycol dimethyl ether (DEGDME) based electrolyte. As a result, the sodium‐ion capacitor delivers an energy density of 42 Wh kg–1 and a high power of 4565 W kg–1 for 3000 cycles at 2.5 A g–1. Furthermore, this capacitor could sustain an energy density of 36 Wh kg–1 at the low temperature of −30 °C and maintain 70% of the capacity after 500 cycles. The strategies of reducing de‐solvation energy and optimizing the solid electrolyte interphase property offers a clear path for developing electrochemical energy storage devices at lower temperatures.
Sharing of Strain Between Nanofiber Forests and Liquid Crystals Leads to Programmable Responses to Electric Fields
Authors: Roh Sangchul , Kim John , Varadharajan Divya , Lahann Joerg , Abbott Nicholas L.
Published: April 2022

Fibers embedded in soft matrices are widely encountered in biological systems, with the fibers providing mechanical reinforcement or encoding of instructions for shape changes. Here, the mechanical coupling of end‐attached polymeric nanofiber forests and liquid crystals (LCs) is explored, where the nanofibers are templated into prescribed shapes by the chemical vapor polymerization of paracyclophane‐based monomers in supported films of the LCs. It is shown that the elastic energies of the nanofibers and LCs are comparable in magnitude, leading to reversible straining of nanofibers via the application of an electric field to the LC. This coupling is shown to encode complex electrooptical responses in the LC (e.g., optical vortices), thus illustrating how LC‐templated nanofiber forests offer the basis of fresh approaches for programming configurational changes in soft materials.
Directional and Adaptive Oil Self‐Transport on a Multi‐Bioinspired Grooved Conical Spine
Authors: Li Yaoxia , Cui Zehang , Li Guoqiang , Bai Haoyu , Dai Ruyuan , Zhou Yingzi , Jiao Yan , Song Yuegan , Yang Yi , Liu Senyun , Cao Moyuan
Published: April 2022

Manipulating oil droplets in an aqueous solution offers great opportunities to develop advanced devices in the fields of water remediation, chemical micro‐reactor, etc. Although conical structures can achieve a directional oil droplet motion, the continuous and adaptive fluid self‐transport in complicated environments is still a challenge. Inspired by the distinctive oil transport capability of fishbone and the anisotropic grooved structure of rice leaves, this work presents a multi‐bioinspired grooved conical spine (BGCS) for improved oil manipulation. Benefiting from the cooperative effect of the asymmetric Laplace pressure and the surface capillary force, the BGCS possesses the reliable functions of ultrafast and continuous oil transport under water, in air, and even across the air–water interface. Compared with the original cone, the BGCS demonstrates a nine times faster transporting velocity and a five times larger capacity. It is envisioned that this updated oil‐collecting cone with its cooperative structure should find real‐world applications.
Robust Memristive Fiber for Woven Textile Memristor
Authors: Liu Yue , Zhou Xufeng , Yan Hui , Zhu Zhengfeng , Shi Xiang , Peng Yahui , Chen Lin , Chen Peining , Peng Huisheng
Published: April 2022

Memristors with an intrinsic crossbar structure and high computing capability offer promising opportunities for the flexible information‐processing component that can well integrate with the interwoven structure of electronic textiles. However, it remains difficult to achieve uniform inorganic memristive layer at nanometer thickness on the curved surface of fiber electrode, thus hindering the applications of textile memristors. Here, a high‐performing and reliable textile memristor made of robust Pt/CsPbBr3 fiber through an electric‐field‐assisted assembly method is reported. The textile memristor exhibits a cycle to cycle variation of less than 8% and an average set voltage of ≈0.16 V, which is lower than that of the majority of planar metal‐oxide memristors. The flexible and mechanically robust Pt/CsPbBr3 fibers are woven into a scalable textile memristor array with good device‐to‐device reproducibility. This textile memristor can be seamlessly integrated with textile electronics toward a smart clothes system to accurately process complicated physiological information, providing an effective interactive interface for intelligent healthcare.
Degradable Silk‐Based Subcutaneous Oxygen Sensors
Authors: Falcucci Thomas , Presley Kayla F. , Choi Jaewon , Fizpatrick Vincent , Barry Jonah , Kishore Sahoo Jugal , Ly Jack T. , Grusenmeyer Tod A. , Dalton Matthew J. , Kaplan David L.
Published: April 2022

Continuous monitoring of biochemical analytes like oxygen is of interest in biomedicine to provide insight into physiology and health. Silk‐protein biomaterials are particularly useful as the scaffold material in oxygen sensors due to silk's unique amphiphilic chemistry, which promotes noncovalent stabilization of the protein and additives in aqueous environments. Silk films containing a water‐insoluble oxygen‐sensing chromophore, Pd (II) tetramethacrylated benzoporphyrin (PdBMAP), are evaluated as optical oxygen sensors in vitro and in vivo. These silk‐chromophore composites are stabilized by the self‐assembled, physically crosslinked protein network. The deaerated phosphorescence lifetime (τm,0 ≈300 µs) of the chromophore in vitro is quenched to 50% of its initial value at ≈31 µm dissolved oxygen, indicating sensing functionality within physiological ranges of oxygen. In vitro enzymatic degradation of the silk films with and without the chromophore is demonstrated. The silk‐chromophore composite films are cytocompatible in vitro, biocompatible in vivo upon implantation in rats, and displayed mechanical properties suitable for subcutaneous implantation. Further, the films maintain oxygen‐sensing function in vivo and demonstrate real‐time sensing capabilities throughout various physiological states (i.e., hyperoxia, normoxia, and hypoxia).
Multimodal Gas Sensor Detecting Hydroxyl Groups with Phase Transition Based on Eco‐Friendly Lead‐Free Metal Halides
Authors: Lee Daseul , Lee Seung‐Jea , Kim Jae Ho , Park Juyun , Kang Yong‐Cheol , Song Myungkwan , Lee Hyung Woo , Kim Han Seul , Choi Jin Woo
Published: April 2022

An electrical and optical responsive chemical‐semiconductor gas sensor is developed using Cu(I) halides with a phase transition mechanism. Cu(I) materials exhibit reversible phase transitions between the Cs3Cu2I5 and CsCu2I3 with different properties, owing to the formation/destruction of the Cs–I and Cu–Cu bonding when the hydroxyl groups are attached/detached. Among various toxic and atmospheric gases, a Cu(I)‐based gas sensor has high selectivity in detecting the hydroxyl group, and the highest sensitivity to water. The reactivity is determined by the polarity, where water with the largest polarity has the strongest attraction for Cu+ and I− ions, letting phase transition occur easily. The multimodal sensor red‐shifts emission from 445 to 575 nm when it detects hydroxyl gas, and the moisture‐sensitive sensor visually confirms response to breaths in less than 5 s and recovery in the air in less than 30 s. The gas sensor can operate at room temperature while applying a constant bias voltage of 1 V, and it also shows excellent sensitivity in a relative humidity range of 15–75%. Furthermore, the sensor maintained ≈90% of its initial responsivity over 1 year.
Aerodynamics‐Based Triboelectric Nanogenerator for Enhancing Multi‐Operating Robustness via Mode Automatic Switching
Authors: Liu Yuan , Yan Wenjie , Han Jiajia , Chen Baodong , Wang Zhong Lin
Published: April 2022

The multi‐operating robustness of triboelectric nanogenerators (TENGs) is still an awkward issue that must be solved to achieve practicality and industrialization. Here, an aerodynamics‐based TENG (AB‐TENG) is developed by combining it with a propeller and rotor, which can switch automatically between contact and separation mode. The separation speed can be reduced to 150 rpm by optimizing the spring stiffness coefficient, which maintains 95.18% of the electrical output after continuous operation for more than 1.378 million cycles. Combining with power management circuit, these capacitors of 0.56, 1, 3.3, and 10 mF can be charged quickly to 3 V within 7.3, 9.3, 16.7, and 43.4 s, respectively. In addition, AB‐TENG can power 6 digital hygrothermographs in parallel by harvesting irregular airflow or drive one Bluetooth‐enabled, 6 commercial LED bulbs of 3 W or 240 green LED lamp beads in parallel, respectively. This work provides an effective strategy to improve the multi‐operating robustness of TENGs, and more importantly, to overcome the mechanical durability and electrical stability difficulties of the technique at high rotational speed caused by abrasion limit of triboelectric materials, and may reveal its potential in the distributed energy and Internet of Things.
Characteristics of ALD‐ZnO Thin Film Transistor Using H2O and H2O2 as Oxygen Sources
Authors: Yang Jun , Bahrami Amin , Ding Xingwei , Lehmann Sebastian , Kruse Nadine , He Shiyang , Wang Bowen , Hantusch Martin , Nielsch Kornelius
Published: April 2022

ZnO thin films are deposited by atomic layer deposition (ALD) using diethylzinc as the Zn source and H2O and H2O2 as oxygen sources. The oxidant‐ and temperature‐dependent electrical properties and growth characteristics are systematically investigated. Materials analysis results suggest that H2O2 provides an oxygen‐rich environment so that the oxygen vacancies (VO) is suppressed, implying a lower carrier concentration and a higher resistivity. The lower growth rate makes it possible for the ZnO thin films to grow along the lower surface energy direction of <002>, leading to a lower Hall mobility. Furthermore, the ZnO semiconductor is integrated into thin film transistor (TFT) devices and the electrical properties are analyzed. The TFT with H2O2‐ZnO grown at 150 °C shows good electrical properties, such as a high field‐effect mobility of 10.7 cm2 V–1 s–1, a high ratio Ion/Ioff of 2 × 107, a sharp subthreshold swing of 0.25 V dec–1, and a low trapping state (Ntrap) of 2.77 × 1012 eV–1 cm–2, which provides a new pathway to optimize the performance of metal‐oxide electronics.
Tuning the Optical and Electrical Properties of Polymer‐Based Nanocomposites by Plasmon‐Induced Electromagnetic Field
Authors: Peng Shih‐Lun , Chen Gang‐Yi , Hsu Su‐Wen
Published: April 2022

For nanocomposites composed of plasmonic nanocrystal and polymers, the plasmon‐induced electromagnetic field (EF) around the plasmonic nanocrystals can be used to change the dielectric environment around them, resulting in the optical and electrical properties of nanocomposites being adjustable. The electrical conductivities of ligand coated on plasmonic nanocrystal and polymer matrix play important roles in controlling the “local” and “overall” dielectric environment of nanocomposites under plasmon‐induced EF. The changes in the dielectric environment of nanocomposites are caused by the rearrangement of molecular chains of ligand and/or polymer matrix around the plasmonic nanocrystals. The optical properties of nanocomposites depend on the “local” and “overall” dielectric environment of nanocomposites, which show a significant change in the plasmon resonance wavelength (blueshift ≈10 nm) under plasmon‐induced EF. However, the electrical properties of nanocomposites depend only on the “overall” dielectric environment of the nanocomposite under plasmon‐induced EF. Nanocomposites are constructed in the conducting polymer matrix resulting in three orders of magnitude increase (from 4 × 10–14 to 10–10 s cm−1) in the electrical conductivity of nanocomposites under plasmon‐induced EF. Such plasmonic nanocrystal‐polymer nanocomposites with highly sensitive optical and electrical properties under external stimuli have potential applications in “electromagnetic field” or “photonic” sensors.
Anomalous Interfacial Electronic Structure of Solid Films of Non‐Planar π‐Conjugated Molecule 6‐Cycloparaphenylene
Authors: Furuichi Takaya , Inoue Takuya , Miyaji Kouki , Kanai Kaname
Published: April 2022

n‐Cycloparaphenylene ([n]CPP) is a non‐planar π‐conjugated molecule with a macrocyclic, hoop‐like molecular structure that allows for control of the electronic structure unlike planar molecules. Thus, [n]CPP has the potential as a novel functional material in organic electronics. In this study, the unique electronic structure of [6]CPP is revealed, which originates from its macrocyclic molecular structure by comparison with p‐sexiphenyl, a linear molecule also consisting of six phenylenes. The morphology of the vapor‐deposited [6]CPP polycrystalline film is found to be highly dependent on the evaporation rate and the type of substrate. It is also found that a [6]CPP molecular layer is formed at the interface between the film and gold substrate, which has a much smaller energy gap than that of the bulk [6]CPP. This anomalous molecular layer is composed of [6]CPP molecules with a smaller dihedral angle than that in the bulk because of the interaction with a gold substrate. When [6]CPP is used as a semiconducting layer in electronic devices, this layer can play a role in improving the charge injection efficiency from the electrode to the [6]CPP film.
Self‐Assembly Silver Nanoparticles Decorated on Gold Nanoislands for Label‐Free Localized Surface Plasmon Resonance Biosensing
Authors: Liu Linlin , Liang Xiongyi , Qiu Guangyu , Guo Chen , Chan Yau Kwan , Wu Chi‐Man Lawrence
Published: April 2022

A nanostructure of self‐assembly silver nanoparticles decorated on gold nanoislands (SAM Ag@AuNIs) is proposed in this article as a sensitive sensing medium for localized surface plasmon resonance (LSPR) biosensing applications. A wide tunable plasmonic sensing range from 472 to 552 nm is found by adjusting the Au–Ag atomic ratio. Biotin is employed as an indicator to investigate the potential biosensing applicability and site‐specific bioactivity of the SAM Ag@AuNIs. In virtue of a white light common‐path sensing system, direct adsorption of biotin on the SAM Ag@AuNIs is measured in label‐free manner with detection limit (LOD) of 2.9 pg mL−1 (11.87 × 10−12 m). It is 105‐fold better than that of TiN film, which is previously reported to provide excellent LSPR LOD after functionalization with biotin. The experimental and computational results indicate that the biotin molecule can selectively immobilize onto the Ag nanoparticles (AgNPs) surface through S–Ag bonding, resulting in site‐specific functionalization. Meanwhile, the geometry of AgNPs/AuNIs provided a coupling effect that helps to improve the sensitivity. Here, AgNPs are, for the first time, reported to be directly functionalized with biotin. The SAM Ag@AuNIs can serve as a desirable plasmonic medium in the biosensing community based on the exceptionally good LOD of biotin.
Commercial‐Like Self‐Cleaning Colored ZrO2‐Based Bilayer Coating for Remarkable Daytime Sub‐Ambient Radiative Cooling
Authors: Liu Henghao , Kang Hongjun , Jia Xin , Qiao Xianshu , Qin Wei , Wu Xiaohong
Published: April 2022

Passive daytime radiative cooling (PDRC) is a low‐carbon energy technology to early achieve the “carbon neutrality” goal. Developing the commercial‐like colored PDRC coatings with sub‐ambient cooling performance is still a big challenge. Herein, a colored bilayer ZrO2‐PVDF PDRC coating with sub‐ambient cooling performance, self‐cleaning, and good weather resistance property is first reported. The colored bilayer coating is composed of a thick ultra‐white ZrO2‐PVDF reflective layer (Rsolar = 0.984) and a thin colorful layer. The obtained red bilayer ZrO2‐PVDF PDRC coating has a high solar reflectance (Rsolar = 0.950), which could realize the maximum temperature drop of 3.0 °C, and the calculated theoretical cooling power is as high as 131.66 W m−2, showing a good sub‐ambient cooling performance. Furthermore, they show a good self‐cleaning property. Meanwhile, the accelerated aging tests prove that they have a good weather resistance. This work provides a low‐cost, simple, and large‐scale method to prepare the commercial‐like colored PDRC coatings with the sub‐ambient cooling performance, showing a great practical application value.
Silver Nanowire Synthesis and Applications in Composites: Progress and Prospects
Authors: Fu Danning , Yang Rendang , Wang Yang , Wang Ruibin , Hua Feiguo
Published: April 2022

Silver nanowires (AgNWs) have gained increased interest as highly conductive and transparent nanomaterials with numerous applications across various fields. Owing to their unique properties (e.g., optical transparency, electrical conductivity, mechanical characteristics, and ease of processing), AgNWs have been extensively investigated for application in light‐emitting diodes, solar cells, electrocatalysis, liquid crystal displays, wearable electronic devices, flexible nanosensors, and supercapacitors. In this review, recent advances in the synthesis of AgNWs (including the polyol, template, wet chemical, and photoreduction methods) are discussed, with a focus on their advantages and disadvantages in terms of AgNW structural regulation. Furthermore, the advantages and applications of AgNW composites, are comprehensively reviewed and analyzed, with a focus on energy storage and optoelectronics, sensors, electromagnetic interference shielding and absorbing materials, nanogenerators, and other applications. The prospects and challenges of AgNW composites in emerging applications are also proposed.
A 3D‐Printed Customizable Platform for Multiplex Dynamic Biofilm Studies
Authors: Dhall Atul , Ramjee Ravikiran , Oh Min Jun , Tao Kevin , Hwang Geelsu
Published: April 2022

Biofilms are communities of microbes that colonize surfaces. While several biofilm experimental models exist, they often have limited replications of spatiotemporal dynamics surrounding biofilms. For a better understanding dynamic and complex biofilm development, this manuscript presents a customizable platform compatible with off‐the‐shelf well plates that can monitor microbial adhesion, growth, and associated parameters under various relevant scenarios by taking advantage of 3D printing. The system i) holds any substrate in a stable, vertical position, ii) subjects samples to flow at different angles, iii) switches between static and dynamic modes during an experiment, and iv) allows multiplexing and real‐time monitoring of biofilm parameters. Simulated fluid dynamics is employed to estimate flow patterns around discs and shear stresses at disc surfaces. A 3D printed peristaltic pump and a customized pH measurement system for real‐time tracking of spent biofilm culture media are equipped with a graphical user interface that grants control over all experimental parameters. The system is tested under static and dynamic conditions with Streptococcus mutans using different carbon sources. By monitoring the effluent pH and characterizing biochemical, microbiological, and morphological properties of cultured biofilms, distinct properties are demonstrated. This novel platform liberates designing experimental strategies for investigations of biofilms under various conditions.
Correlated Dynamics of Free and Self‐Trapped Excitons and Broadband Photodetection in BEA2PbBr4 Layered Crystals
Authors: Li Gefei , Zhang Yong , Wang Wenhui , Gao Lei , Ren Yukun , Che Junyan , Mo Chunjing , Liu Hongwei , Zhao Weijie , Lu Junpeng , Ni Zhenhua
Published: April 2022

Self‐trapped excitons (STEs) exert a profound impact on the optical properties and device applications of 2D halide perovskites. Particularly distinct exciton self‐trapping and detrapping processes can facilitate the intelligent design of perovskite optoelectronic devices with emerging functionalities. Thus, a comprehensive understanding and regulation of exciton trapping and detrapping dynamics are highly desired. Herein, the authors report a 2D lead halide perovskite (BEA2PbBr4 where BEA is 2‐bromine ethylamine) with exceptional broadband photoluminescence (PL), which originates from multiple STE states. In particular, the unique energy‐level configuration of STEs with respect to free excitons is revealed by exploiting optical spectroscopy. Consequently, these distinct phenomena empower the broadband photodetection capability of BEA2PbBr4 photodetectors over a wide range from ultraviolet to near‐infrared wavelengths. These results provide an essential understanding of the intriguing photophysics of STEs and shed new light on the future development of single‐component perovskite broadband optoelectronic devices.
A Miniaturized Anechoic Chamber: Omnidirectional Impedance Matching Based on Truncated Spatial Kramers–Kronig Medium
Authors: Li Quanping , Luo Yu , Liu Dongjue , Gao Yuan , Zhang Jingjing , Ran Lixin , Ye Dexin
Published: April 2022

Spatial Kramers–Kronig (KK) medium provides a new platform to achieve omnidirectionally reflectionless absorption without using any gain elements. However, impedance‐matched spatial KK media realized in previous experiments generally have flat geometries with large transverse dimensions. Realizing finite spatial KK absorbers in free space background is important for many practical applications but has not been demonstrated experimentally thus far. Here, the concept of spatial KK relation to cylindrical coordinates is extended and a double‐resonance space‐frequency KK permittivity profile is implemented in a circular geometry. Omnidirectional impedance matching to free space is achieved by truncating the spatial KK absorber at the boundary where the relative permittivity is unity. For the experimental verification, a two‐dimensional 6.6‐wavelength‐diameter doughnut‐shaped anechoic chamber is implemented using the designed spatial KK medium. The measured electric field distributions and experimental imaging confirm the omnidirectionally reflectionless property, demonstrating that this miniaturized anechoic chamber is suitable for electrically small scatterer measurements and imaging. The proposed finite spatial KK absorber and fabricated miniaturized anechoic chamber show great promises for electromagnetic shielding and compatibility.
Numerical Simulation of n‐MoSe2/p‐Si Solar Cells by AFORS‐HET
Authors: Shen Yuheng , Yu Meng , Huang Ruiming , Cheng Qijin
Published: April 2022

For a thorough understanding of n‐MoSe2/p‐Si heterojunction solar cells, the effect of the MoSe2 band gap, the back electrode work function, the density of interface states, as well as the introduction of the interface layer on the performance of MoSe2/Si heterojunction solar cells is systematically investigated via AFORS‐HET simulation software. It is shown that a higher MoSe2 band gap, a higher back electrode work function, a lower density of interface states, and an introduction of a thin intrinsic hydrogenated amorphous silicon as an interface layer, are favorable for the achievement of high‐performance MoSe2/Si heterojunction solar cells. Through the simulation optimization, a photovoltaic conversion efficiency of 12.31% with an open‐circuit voltage of 0.61 V, a short‐circuit current density of 26.47 mA cm−2, as well as a fill factor of 75.4%, can be obtained for the n‐MoSe2/p‐Si heterojunction solar cells. To interpret the obtained simulation results, the authors have carefully analyzed the current–voltage curves, energy band diagrams, electron and hole concentration distributions, electron and hole recombination rates, etc. This study indicates that silicon‐based heterojunction solar cells with MoSe2 as an active layer are of great significance in the development of high‐efficiency photovoltaic devices.
Density Functional Theory‐Based Calculations for 2D Hexagonal Lanthanide Metals
Authors: Sangolkar Akanksha Ashok , Jha Sakshi , Pawar Ravinder
Published: April 2022

Scrutiny of the stability, properties, and applications of 2D metals belonging to s‐, p‐, and d‐block series has acquired intense research interest in the past few years. The present report is solely focused to systematically explore the stability and properties of 2D hexagonal (HX) lanthanides employing density functional theory calculations. To probe the dynamical stability of these materials, the phonon dispersion calculation is performed. The mechanical stability is analyzed on the basis of the 2D bulk modulus and elastic constant values. Further, to unravel the electronic properties of the 2D metals, electronic band structure, electron localization function, and the work function values are estimated. Moreover, en route to explore their magnetic properties, spin polarized density of states calculation is carried out and the ground state magnetic behavior is studied by considering ferromagnetic and antiferromagnetic spin configurations. Result explicitly demonstrates that 11 lanthanide metals are dynamically stable as an atomically thin 2D HX films. All of them are conducting in nature exhibiting ferromagnetic behavior in their ground state. These results offer the fundamentals of stability and properties of 2D HX lanthanides which can lay the foundation for exploring their diverse future applications.
Molecular Signature of Astrocytes for Gene Delivery by the Synthetic Adeno‐Associated Viral Vector rAAV9P1
Authors: Bauer Amelie , Puglisi Matteo , Nagl Dennis , Schick Joel A , Werner Thomas , Klingl Andreas , El Andari Jihad , Hornung Veit , Kessler Horst , Götz Magdalena , Grimm Dirk , Brack‐Werner Ruth
Published: April 2022

Astrocytes have crucial functions in the central nervous system (CNS) and are major players in many CNS diseases. Research on astrocyte‐centered diseases requires efficient and well‐characterized gene transfer vectors. Vectors derived from the Adeno‐associated virus serotype 9 (AAV9) target astrocytes in the brains of rodents and nonhuman primates. A recombinant (r) synthetic peptide‐displaying AAV9 variant, rAAV9P1, that efficiently and selectively transduces cultured human astrocytes, has been described previously. Here, it is shown that rAAV9P1 retains astrocyte‐targeting properties upon intravenous injection in mice. Detailed analysis of putative receptors on human astrocytes shows that rAAV9P1 utilizes integrin subunits αv, β8, and either β3 or β5 as well as the AAV receptor AAVR. This receptor pattern is distinct from that of vectors derived from wildtype AAV2 or AAV9. Furthermore, a CRISPR/Cas9 genome‐wide knockout screening revealed the involvement of several astrocyte‐associated intracellular signaling pathways in the transduction of human astrocytes by rAAV9P1. This study delineates the unique receptor and intracellular pathway signatures utilized by rAAV9P1 for targeting human astrocytes. These results enhance the understanding of the transduction biology of synthetic rAAV vectors for astrocytes and can promote the development of advanced astrocyte‐selective gene delivery vehicles for research and clinical applications.
Colloidal III–V Quantum Dot Photodiodes for Short‐Wave Infrared Photodetection
Authors: Leemans Jari , Pejović Vladimir , Georgitzikis Epimitheas , Minjauw Matthias , Siddik Abu Bakar , Deng Yu‐Hao , Kuang Yinghuan , Roelkens Gunther , Detavernier Christophe , Lieberman Itai , Malinowski Paweł E. , Cheyns David , Hens Zeger
Published: April 2022

Short‐wave infrared (SWIR) image sensors based on colloidal quantum dots (QDs) are characterized by low cost, small pixel pitch, and spectral tunability. Adoption of QD‐SWIR imagers is, however, hampered by a reliance on restricted elements such as Pb and Hg. Here, QD photodiodes, the central element of a QD image sensor, made from non‐restricted In(As,P) QDs that operate at wavelengths up to 1400 nm are demonstrated. Three different In(As,P) QD batches that are made using a scalable, one‐size‐one‐batch reaction and feature a band‐edge absorption at 1140, 1270, and 1400 nm are implemented. These QDs are post‐processed to obtain In(As,P) nanocolloids stabilized by short‐chain ligands, from which semiconducting films of n‐In(As,P) are formed through spincoating. For all three sizes, sandwiching such films between p‐NiO as the hole transport layer and Nb:TiO2 as the electron transport layer yields In(As,P) QD photodiodes that exhibit best internal quantum efficiencies at the QD band gap of 46±5% and are sensitive for SWIR light up to 1400 nm.
Multi‐Mode and Dynamic Persistent Luminescence from Metal Cytosine Halides through Balancing Excited‐State Proton Transfer
Authors: Xiao Guowei , Fang Xiaoyu , Ma Yu‐Juan , Yan Dongpeng
Published: April 2022

Persistent luminescence has attracted great attention due to the unique applications in molecular imaging, photodynamic therapy, and information storage, among many others. However, tuning the dynamic persistent luminescence through molecular design and materials engineering remains a challenge. In this work, the first example of excitation‐dependent persistent luminescence in a reverse mode for smart optical materials through tailoring the excited‐state proton transfer process of metal cytosine halide hybrids is reported. This approach enables ultralong phosphorescence and thermally activated delayed fluorescence emission colors highly tuned by modulation of excitation wavelength, time evolution, and temperature, which realize multi‐mode dynamic color adjustment from green to blue or cyan to yellow‐green. At the single crystal level, the 2D excitation/space/time‐resolved optical waveguides with triple color conversion have been constructed on the organic‐metal halide microsheets, which represent a new strategy for multi‐dimensional information encryption and optical logic gate applications.
Toward Efficiency Limits of Crystalline Silicon Solar Cells: Recent Progress in High‐Efficiency Silicon Heterojunction Solar Cells
Authors: Sun Zhaoqing , Chen Xiaoqing , He Yongcai , Li Jingjie , Wang Jianqiang , Yan Hui , Zhang Yongzhe
Published: April 2022

Photovoltaic (PV) technology is ready to become one of the main energy sources of, and contributers to, carbon neutrality by the mid‐21st century. In 2020, a total of 135 GW of PV modules were produced. Crystalline silicon solar cells dominate the world's PV market due to high power conversion efficiency, high stability, and low cost. Silicon heterojunction (SHJ) solar cells are one of the promising technologies for next‐generation crystalline silicon solar cells. Compared to the commercialized homojunction silicon solar cells, SHJ solar cells have higher power conversion efficiency, lower temperature coefficient, and lower manufacturing temperatures. Recently, several new record efficiencies have been achieved. To meet the continued demand for high‐efficiency solar cells, expectations for large‐scale mass production of SHJ solar cells are rising. To approach the efficiency limit and industrialization of SHJ solar cells, serious attempts have been made, yielding higher short‐circuit current, open‐circuit voltage, and fill factor. In this article, these recent advancements are reviewed, which reveals the future roadmap for approaching the efficiency limit.
Covalent Organic Framework for Rechargeable Batteries: Mechanisms and Properties of Ionic Conduction
Authors: Cao Yu , Wang Meidi , Wang Hongjian , Han Chengyu , Pan Fusheng , Sun Jie
Published: April 2022

Ionic conduction plays a critical role in the process of electrode reactions and the charge transfer kinetics in a rechargeable battery. Covalent organic frameworks (COFs) have emerged as an exciting new class of ionic conductors, and have made great progress in terms of their application in rechargeable batteries. The unique features of COFs, such as well‐defined directional channels, functional diversity, and structural robustness, endow COF‐based conductors with a low ionic diffusion energy barrier and excellent temperature tolerance, which are much superior to the classic inorganic or polymer conductors. Here, a comprehensive analysis and summary of the unique ion‐conducting behavior of COF‐based conductors are presented, and the design principles for ion‐conducting COFs are emphasized. Moreover, a systematic overview of the recent progress in the development of ion‐conducting COFs serving as electrodes, separators, solid electrolytes, and artificial interphase materials for diverse battery applications, such as metal‐ion batteries, lithium metal batteries, lithium–sulfur batteries, lithium–CO2batteries, zinc–air batteries, etc., is proposed. This review is expected to provide theoretical guidance for design of novel kinds of ionic conductor bearing intrinsic framework structures and to boost further research enthusiasm for ion‐conducting COFs in rechargeable batteries.
Simultaneously Decreasing the Bandgap and Voc Loss in Efficient Ternary Organic Solar Cells
Authors: Yan Yangjun , Zhang Yajie , Liu Yanan , Shi Yanan , Qiu Dingding , Deng Dan , Zhang Jianqi , Wang Boxin , Adil Muhammad Abdullah , Amin Kamran , Memon Waqar Ali , Wang Mengni , Zhou Huiqiong , Zhang Xinghua , Wei Zhixiang
Published: April 2022

Ternary architecture is a promising strategy to further boost the performance of organic solar cells (OSCs). Reducing the bandgap of the active layer materials not only widens the absorption wavelength range and enhances the short‐circuit current (Jsc) of the OSC, but also decreases the open‐circuit voltage (Voc) of the device, leading to a trade‐off situation for the optimization of the material system. Herein, a small‐molecule donor BTID‐2F, featuring a narrower bandgap than that of PM6, is introduced into a PM6:Y6 based system. The redshift in external quantum efficiency indicates the narrower bandgap and better aggregation in the ternary blends than those of binary ones. Interestingly, lower energy disorder and energy loss are also attained for the ternary devices, leading to higher Voc. Furthermore, owing to the suppressed recombination and morphological optimization, a simultaneous enhancement in the Jsc and fill factor boosts the power conversion efficiency (PCE) of ternary OSC to 17.9% compared to 16.62% for the binary device. Likewise, replacing the acceptor with the L8‐BO molecule further improves the ternary PCE to 18.52%. This work indicates an emerging approach for fabricating high‐performance ternary OSCs with a decreased bandgap and increased Voc.
General Synthesis of Transition‐Metal‐Based Carbon‐Group Intermetallic Catalysts for Efficient Electrocatalytic Hydrogen Evolution in Wide pH Range
Authors: Pu Zonghua , Liu Tingting , Zhang Gaixia , Chen Zhangsen , Li Dong‐Sheng , Chen Ning , Chen Weifeng , Chen Zhangxing , Sun Shuhui
Published: April 2022

Alloying is a well‐accepted strategy for modulating the electronic structures of catalyst materials. Compared to disordered solid‐solution alloys, intermetallic compounds feature ordered atomic arrangements and provide a unique platform with a rich and diverse resource to study the relationships among chemical composition, atomic structure, electronic structure, and properties. Unfortunately, it is still challenging to synthesize the nanostructures of intermetallic compounds for catalysis research. In this study, a series of intermetallic silicides (PtSi, RhSi, Ru2Si3, IrSi), germanide (Ru2Ge3), and stannides (Ru3Sn7, IrSn2, PdSn3, PdSn2) are rationally designed and constructed through a facile molten‐salt‐assisted route. As an example, the PtSi not only shows highly desirable electrocatalytic properties for the hydrogen evolution reaction (HER) with low overpotentials of 22, 38, and 66 mV at a current density of 10 mA cm‐2 in acidic, alkaline, and neutral media, respectively, but exhibits superior durability, as well as >97% faradic efficiency. The theoretical calculations suggest that the introduction of Si to Pt could weaken the binding energy between Pt and H atoms, which further facilitates the hydrogen generation during the HER process. Further, the findings inspired the authors to develop other kinds of metal‐based carbon‐group intermetallic phases with excellent activity in the HER and beyond.
Li2S4 Anchoring Governs the Catalytic Sulfur Reduction on Defective SmMn2O5 in Lithium–Sulfur Battery
Authors: Wang Li , Hu Zhonghao , Wan Xiang , Hua Wuxing , Li Huan , Yang Quan‐Hong , Wang Weichao
Published: April 2022

The introduction of sulfur redox electrocatalysts has been considered to be an effective strategy to anchor polysulfides on the cathode and reduce the energy barriers of the reactions. Due to the complexity of sulfur redox reactions (SRR/SER), there exist few descriptors to correlate the catalytic performance and the underlying electronic structures of a given catalyst, which inhibits the development of lithium−sulfur catalysts. In this article, upon mullite oxide SmMn2O5 with various substitutional defects, density functional theory calculations are used to probe the structure–property relationships. It is found that there exists no scaling relationship among the polysulfide binding energies, indicating that the catalytic performance can be tuned by a key intermediate individually. Statistical analysis of various models with different S‐containing intermediates shows that only the Li2S4 binding energy has a linear correlation with the overpotential, showing the dominant role of Li2S4 anchoring to determine the catalytic performance. The electronic structure analysis combined with machine learning further quantitatively verifies the coeffect of charge transfer, electronegativity, and work function on the binding strength of the polysulfide Li2S4. This work provides a theoretical understanding of the complex SRR/SER mechanisms and sheds light on the rational design of a sulfur redox catalyst.
Semitransparent Organic Solar Cells with Efficiency Surpassing 15%
Authors: Jing Jianhua , Dong Sheng , Zhang Kai , Zhou Zhisheng , Xue Qifan , Song Yu , Du Zurong , Ren Minrun , Huang Fei
Published: April 2022

Semitransparent organic solar cells (ST‐OSCs) have promising prospects for building or vehicle integrated solar energy harvesting with energy generation and see‐through function. How to achieve both an adequate average visible transmittance (AVT) and high‐power conversion efficiency (PCE) is always the key issue. Herein, a simple but effective strategy for constructing high performance ST‐OSCs by introducing a small molecule [2‐(9‐H‐Carbazol‐9‐yl) ethyl] phosphonic acid (2PACz) into a low‐donor content active layer is reported. The fill factor is improved from 70.5% to 75.5% and correlated to the mitigated charge recombination and strengthened charge extraction, further ascribed to the enhanced build‐in potential, reduced charge transport resistance, and favorable film morphology. By combining the unique nature of 2PACz, that can spontaneously form in situ self‐organized hole transport interlayers under bulk‐heterojunction films, PEDOT‐free ST‐OSCs with a PCE of 15.2%, amongst the highest values in this field, is achieved with an AVT of 19.2%. Moreover, an outstanding light utilization efficiency of 3.39% is also obtained with an AVT of 30.0% and a PCE of 11.3% in a translucent device by tuning the electrode. The work demonstrates a new and simple strategy for achieving excellent AVT and PCE in ST‐OSCs with simplified device structure.