bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elastic Plasmonic‐Enhanced Fabry–Pérot Cavities with Ultrasensitive Stretching Tunability
Authors: Güell‐Grau Pau , Pi Francesc , Villa Rosa , Eskilson Olof , Aili Daniel , Nogués Josep , Sepúlveda Borja , Alvarez Mar 
Published: December 2021

AbstractThe emerging stretchable photonics field faces challenges, like the robust integration of optical elements into elastic matrices or the generation of large optomechanical effects. Here, the first stretchable plasmonic‐enhanced and wrinkled Fabry–Pérot (FP) cavities are demonstrated, which are composed of self‐embedded arrays of Au nanostructures at controlled depths into elastomer films. The novel self‐embedding process is triggered by the Au nanostructures’ catalytic activity, which locally increases the polymer curing rate, thereby inducing a mechanical stress that simultaneously pulls the Au nanostructures into the polymer and forms a wrinkled skin layer. This geometry yields unprecedented optomechanical effects produced by the coupling of the broad plasmonic modes of the Au nanostructures and the FP modes, which are modulated by the wrinkled optical cavity. As a result, film stretching induces drastic changes in both the spectral position and intensity of the plasmonic‐enhanced FP resonances due to the simultaneous cavity thickness reduction and cavity wrinkle flattening, thus increasing the cavity finesse. These optomechanical effects are exploited to demonstrate new strain‐sensing approaches, achieving a strain detection limit of 0.006%, i.e., 16‐fold lower than current optical strain‐detection schemes.
Formation of MoO3/Organic Interfaces
Authors: Wu Yan , Hu Juntao , Yang Zhenxin , Wang Dengke , Zhao Yong‐Biao , Zhang Tao , Chen Nan , Wu Di , Lu Zheng‐Hong 
Published: December 2021

AbstractMolybdenum trioxide (MoO3) has been extensively used in numerous organic semiconductor devices for hole injection and extraction. In this paper, photoelectron spectroscopy combined with cleavage and sputter depth profile has been used to probe the structures of buried MoO3/organic semiconductor interfaces. Organics used in this work include: tris(4‐carbazoyl‐9‐ylphenyl)amine (TCTA), N,N′‐bis(naphthalene‐l‐yl)‐N,N′‐bis(phenyl)benzidine (NPB), 4,4′‐bis(carbazol‐9‐yl)‐2,2′‐biphenyl (CBP), and 1,3‐bis(N‐carbazolyl) benzene (mCP). It is found that there are two distinct types of interfaces: sharp interfaces (type‐I) where the oxide layer has limited or no diffusion when deposited on organics that have a high glass transition temperature such as TCTA and NPB; mixed interfaces (type‐II) where the formation of interfaces is followed by significant diffusion and reaction on organics having low glass transition temperatures such as CBP and mCP. The causes for these two types of interfaces are discussed.
Field‐Effect Control in Hole Transport Layer Composed of Li:NiO/NiO for Highly Efficient Inverted Planar Perovskite Solar Cells
Authors: Zhao Liang , Sun Xuewen , Yao Qiannan , Huang Sheng , Zhu Lei , Song Jian , Zhao Yulong , Qiang Yinghuai 
Published: December 2021

AbstractPerovskite solar cells (PSCs) have been recognized as fascinating optoelectronic devices with a rapid progress of the power conversion efficiency (PCE). However, serious carrier recombination at charge transport layer (CTL)/perovskite interface limits further development of PSCs. Therefore, carrier dynamics at interface should be finely regulated to achieve a satisfied performance. Herein, a hole transport layer (HTL) is developed with a bilayer film composed of Li:NiO/NiO, in which NiO directly contacts with perovskite film. The prepared HTL is a p‐p+ homojunction as Li:NiO film has higher concentration of carrier than NiO. Energy level alignment in Li:NiO/NiO HTL reflects a hole transport improvement by both built‐in electric field and interface effective field. The additional drive forces generated by the above field effects in HTL present a significant enhancement for carrier extraction and transport at HTL/perovskite interface. As a result, the inverted planar PSC with the Li:NiO/NiO HTL delivers an improved PCE up to 19.04% from 15.40% of the control one, which also shows a high fill factor of 82.83%, indicating a low level of carrier nonradiative recombination. This work provides new insights on the carrier dynamics control in CTL/perovskite interface, which is meaningful for designing excellent PSCs.
Stability and Degradation of Metal–Organic‐Framework Films under Ambient Air Explored by Uptake and Diffusion Experiments
Authors: Li Chun , Chandresh Abhinav , Zhang Zejun , Moulai Sarah , Heinke Lars 
Published: December 2021

AbstractThe loading with guest molecules is the key feature for most applications of metal–organic frameworks (MOFs). The limited stability of MOFs against environmental factors, like humid air, is often a severe problem which hinders real‐life applications. Here, the stability of four common MOFs, UiO‐66, UiO‐67, HKUST‐1, and ZIF‐8, under long‐term exposure to humid air and under exposure to water vapor is explored. Transient uptake experiments with toluene and other volatile organic compounds as probe molecules are combined with structural investigations via X‐ray diffraction and infrared spectroscopy. In line with previous publications showing the structural stability of ZIF‐8 and UiO‐66, it is found that its uptake properties are not affected by exposure to air. On the other hand, HKUST‐1 shows clear structural decomposition in air and degradation of the uptake properties. Unexpectedly, while the diffraction and spectroscopy data of UiO‐67 do not suggest a corrosion of the structure upon air exposure, the guest‐loading data show a strong decrease of the uptake amount and a deceleration of the uptake rate. Both features strongly indicate the formation of surface barriers for the mass transfer in UiO‐67, like in HKUST‐1. The study underlines the importance of transient uptake experiments for characterizing the stability of MOF materials.
4D Printing of Surface Morphing Hydrogels
Authors: Liaw Chya‐Yan , Pereyra Jorge , Abaci Alperen , Ji Shen , Guvendiren Murat 
Published: December 2021

AbstractPolymeric systems displaying spontaneous formation of surface wrinkling patterns are useful for a wide range of applications, such as diffraction gratings, flexible electronics, smart adhesives, optical devices, and cell culture platforms. Conventional fabrication techniques for wrinkling patterns involves multitude of processing steps and impose significant limitations on fabrication of hierarchical patterns, creating wrinkles on 3D and nonplanar structures, the scalability of the manufacturing process, and the integration of wrinkle fabrication process into a continuous manufacturing process. In this work, 4D printing of surface morphing hydrogels enabling direct fabrication of wrinkling patterns on curved and/or 3D structures with user‐defined and spatially controlled pattern geometry and size is reported. The key to successful printing is to tailor the photopolymerization time and partial crosslinking time of the hydrogel inks. The interplay between crosslinker concentration and postprinting crosslinking time allow for the control over wrinkling morphology and the characteristic size of the patterns. The pattern alignment is controlled by the print strut size—the size of the solid material extruded from the print nozzle in the form of a line. To demonstrate the utility of the approach, tunable optical devices, a solvent/humidity sensor for microchips, and cell culture platforms to control stem cell shape are fabricated.
Graded Kirigami Composites for Programmed Strain Distributions
Authors: Haque A B M Tahidul , Hwang Dohgyu , Bartlett Michael D. 
Published: December 2021

AbstractStretchable devices and components have emerged as a vital platform for wearable electronics, biomedical sensors, and soft robotics. However, the soft‐rigid interfaces that arise when integrating rigid components with soft and deformable substrates can cause stress concentrations, leading to premature failure of devices at these multi‐material interfaces. Here, a stiffness‐graded kirigami composite is introduced to control strain transitions at soft‐rigid interfaces. The graded composite consists of soft elastomers bonded to rigid kirigami films with defined beam architectures to tune the stiffness gradient along the loading direction. Kirigami geometry is designed by coupling finite element analysis with experimental digital image correlation to achieve diverse strain profiles for flexible interfaces. Furthermore, an inverse design method is utilized to determine kirigami patterns to obtain predefined strain fields. These stiffness‐graded kirigami composites create opportunities for more robust soft‐rigid interfaces and defect‐tolerant stretchable devices and robots.
Two‐Dimensional Nanomaterials for the Development of Efficient Gas Sensors: Recent Advances, Challenges, and Future Perspectives
Authors: Kiani Maryam , Rehman Majeed Ur , Tian Xiaoqing , Yakobson Boris 
Published: December 2021

AbstractThe advancement of nanotechnology has produced a huge potential to prepare highly sensitive and portable sensors with low cost and low energy consumption. Here, a comprehensive review of the recent development of two‐dimensional nanomaterials for gas sensors is presented. Emerging kinds of two‐dimensional nanomaterials‐based sensors with high surface‐to‐volume ratio and porous nanostructures are considered superior for the adsorption of gas molecules, for various gases have been discussed in this review. In addition, strategies that can enhance sensor performance by nanomaterials design and synthesis are also discussed and elaborated for the novel two‐dimensional nanomaterials to the development of sensing technology. Finally, the current challenges have been summarized and future perspectives for the development of gas sensors are also suggested.
Recent Advances and Perspectives of Photostability for Halide Perovskite Solar Cells
Authors: Wang Zhen , Zhang Zeyu , Xie Li , Wang Shurong , Yang Chenguang , Fang Changqing , Hao Feng 
Published: December 2021

AbstractHalide perovskite solar cells (PSCs) have attracted much attention in the next generation of photovoltaic devices due to their low material costs, simple preparation process, and excellent power conversion efficiency (PCE). However, the poor photostability severely limits their commercial application. In this review, the degradation mechanism of PSCs under different light conditions, and various recovery mechanisms are discussed in detail, including i) the degradation of hybrid perovskite under visible light and ultraviolet (UV) light; ii) the degradation of inorganic perovskite under the mixed conditions of oxygen, moisture, and light; iii) the superoxide promoted degradation of perovskite under the combined action of photo‐oxygen; iv) photoinduced ion migration and phase segregation in mixed halide perovskites. Moreover, recent approaches to improve the photostability of PSCs are further summarized and discussed. Among them, the interface modification, the structural optimization of perovskite layer, the material selection of carrier transport layers, and the associated encapsulation technology of PSCs are essential to the photostability of PSCs. A perspective and outlook toward more photo‐stable PSCs are further given.
Reversible Kinetic Trapping of FUS Biomolecular Condensates
Authors: Chatterjee Sayantan , Kan Yelena , Brzezinski Mateusz , Koynov Kaloian , Regy Roshan Mammen , Murthy Anastasia C. , Burke Kathleen A. , Michels Jasper J. , Mittal Jeetain , Fawzi Nicolas L. , Parekh Sapun H. 
Published: December 2021

AbstractFormation of membrane‐less organelles by self‐assembly of disordered proteins can be triggered by external stimuli such as pH, salt, or temperature. These organelles, called biomolecular condensates, have traditionally been classified as liquids, gels, or solids with limited subclasses. Here, the authors show that a thermal trigger can lead to formation of at least two distinct liquid condensed phases of the fused in sarcoma low complexity (FUS LC) domain. Forming FUS LC condensates directly at low temperature leads to formation of metastable, kinetically trapped condensates that show arrested coalescence, escape from which to untrapped condensates can be achieved via thermal annealing. Using experimental and computational approaches, the authors find that molecular structure of interfacial FUS LC in kinetically trapped condensates is distinct (more β‐sheet like) compared to untrapped FUS LC condensates. Moreover, molecular motion within kinetically trapped condensates is substantially slower compared to that in untrapped condensates thereby demonstrating two unique liquid FUS condensates. Controlling condensate thermodynamic state, stability, and structure with a simple thermal switch may contribute to pathological protein aggregate stability and provides a facile method to trigger condensate mixing for biotechnology applications.
Polarization‐Induced Band‐Alignment Transition and Nonvolatile p‐n Junctions in 2D Van der Waals Heterostructures
Authors: Yang Mingjun , Shu Haibo , Li Yanyan , Cao Dan , Chen Xiaoshuang 
Published: December 2021

Abstract2D van der Waals (vdW) p‐n junctions based on vertically stacked atomically thin semiconductor materials have shown tremendous potential in high‐performance integrated electronics and optoelectronics. However, unlike traditional semiconductors, the conventional doping methods to achieve p‐type and n‐type doping in 2D semiconductors remain a large challenge due to their ultrathin structures with limited physical space. Here, by means of density functional theory computations, a nonvolatile doping strategy to obtain self‐defined p‐n junctions in 2D vdW heterostructures created by assembling monolayer transition metal dichalcogenides (TMDs) on polar semiconductors (PSs) is reported. The calculated results show that the quantum‐confined Stark effect causes the band inclination of 2D PSs along the polarization direction, which allows to manipulate the type of band alignment and spatial distribution of carriers in the heterostructures via the polarization modulation. In particular, the realization of nonvolatile p‐n junctions in type‐III TMD/PS heterostructures with ultrahigh carrier concentration (≈1013 ‐ 1014 cm‐2) is demonstrated, and the spatial distribution of charge carriers in the heterostructures can be tuned by the polarization switching. This work provides a nondestructive doping strategy to obtain programmable vdW p‐n junctions with high carrier concentration and band‐engineering approach for the development of versatile 2D electronics and optoelectronics.
Impact of Bracing on Large Format Prismatic Lithium‐Ion Battery Cells during Aging
Authors: Daubinger Philip , Schelter Matthias , Petersohn Ronny , Nagler Felix , Hartmann Sarah , Herrmann Matthias , Giffin Guinevere A. 
Published: December 2021

AbstractTo reduce the ecological footprint and to increase the lifetime of lithium‐ion batteries (LIBs), it is necessary to understand aging phenomena inside the cells during cycling. In this study, the positive effect of external pressure through bracing the cells on aging is investigated for automotive battery cells with more than 7000 cycles. After cycling, the aged cells are studied by using post‐mortem analysis. It is shown that bracing does not affect the anode and cathode in the same manner. A lack of external pressure results in lithium plating due to contact losses on the anode. Such a loss of lithium inventory plays only a small role in the braced cells. However, the structural and morphological degradation, such as particle cracking at the cathode, is significant. Half‐cell tests of aged and unaged anode samples extracted from the automotive cells confirm the post‐mortem findings, where only minimal differences can be seen for the braced cell. In contrast, the aged cathodes from braced cells demonstrate substantial capacity fade in half‐cell measurements as compared to the cathodes extracted from the unbraced cell. Finally, a new concept of the mechanical state of health (mechanical SOH) is introduced to correlate mechanical effects with electrode degradation.
Collectively Exhaustive Hybrid Triboelectric Nanogenerator Based on Flow‐Induced Impacting‐Sliding Cylinder for Ocean Energy Harvesting
Authors: Kim Ji‐Seok , Kim Junyoung , Kim Jong‐Nam , Ahn Junseong , Jeong Jun‐Ho , Park Inkyu , Kim Daegyoum , Oh Il‐Kwon 
Published: December 2021

AbstractFor the sustainable application of remote sensing and monitoring in the ocean environment, energy harvesting technology based on flow‐induced vibration is in the spotlight. Herein, based on the flow‐induced self‐excitation of an impacting‐sliding cylinder, a collectively exhaustive hybrid triboelectric nanogenerator (TENG) is reported, that utilizes both freestanding‐sliding (FS) and contact‐separation (CS) modes. Most importantly, the flow‐induced impacting cylinder (FIC) between two side walls is newly implemented to resolve the critical problem of the lock‐in phenomena occurring in conventional vortex‐induced vibration systems of circular cylinders. Owing to the presence of two side walls, the FIC based TENG (FIC‐TENG) shows a stable electrical power generation in a wide range of flow velocity (0.05–1.02 m s−1) without lock‐in phenomena. In addition, the collectively exhaustive FIC‐TENG can be used to continuously produce electric power utilizing both FS and CS hybrid modes. The energy harvesting performance is greatly enhanced by adopting nanopatterns on triboelectric surfaces in the CS mode TENG and a frequency upconversion effect of interdigitated electrodes in the FS mode TENG, resulting in proper remote operation of a wireless fidelity thermometer.
An Efficient Power Management System Using Dynamically Configured Multiple Triboelectric Nanogenerators and Dual‐Parameter Maximum Power Point Tracking
Authors: Chandrarathna Seneke Chamith , Graham Sontyana Adonijah , Ali Muhammad , Yu Jae Su , Lee Jong‐Wook 
Published: December 2021

AbstractTriboelectric nanogenerators (TENGs) have shown great potential as sustainable energy sources with the advantages of a lightweight, low cost, simple fabrication, and small size. Nevertheless, schemes for efficient power extraction from TENGs remains difficult, partly because of their short, high‐voltage (HV) pulse output. The available power from a single TENG is not usually enough for practical applications. An efficient power management system for TENGs using a dynamically reconfigured combining method and dual‐parameter maximum power point tracking (MPPT) is proposed. A series to parallel/parallel to series (SPPS) adaptive control method, which dynamically reconfigures the connection of multiple TENGs, efficiently combines the outputs. An MPPT method, which adjusts the dual parameters in a closed‐loop, provides a wide range for matching the high output impedance (≈MΩ) of TENGs. The proposed technique is implemented using a 416 nW energy harvester interface integrated circuit (EHI‐IC), realized using a 180 nm, 48 V Bipolar‐CMOS‐DMOS (BCD) process. Measured results show that the proposed approach achieves a 159‐fold improvement in power extraction compared to the results without EHI‐IC. Finally, a triboelectric energy harvesting ball (T‐EHB), which combines 12 TENG pairs for multi‐axis excitation, and several examples of device powering are presented using the T‐EHB.
Zero‐Strain Structure for Efficient Potassium Storage: Nitrogen‐Enriched Carbon Dual‐Confinement CoP Composite
Authors: Yun Yuanxing , Xi Baojuan , Tian Fang , Chen Weihua , Sun Wenping , Pan Hongge , Feng Jinkui , Qian Yitai , Xiong Shenglin 
Published: December 2021

AbstractA new type of anode material in which small‐sized CoP nanoparticles coated with N‐doped carbon are immobilized into 1D nitrogen‐doped carbon frameworks (CoP@NC⊂NCFs) is accurately synthesized via self‐template catalysis. The hierarchical structure bears various structural advantages, including more active sites and ultrahigh electrical conductivity provided by enriched nitrogen, strong interface interaction between CoP and N‐doped carbon, and the stability of the structure. As a result, the rapid potassium ion reaction kinetics and the strong adsorption of potassium ions of CoP are realized, verified by galvanostatic intermittent titration and density function theory calculations. In addition, through the advanced in situ characterization techniques, the solid‐solution reaction mechanism of CoP and potassium ions is clarified. The zero‐strain structure of CoP further ensures structural robustness, giving CoP@NC⊂NCFs excellent potassium storage properties, especially cycle stability with a capacity of ≈206 mAh g−1 at 0.1 A g−1 for 1200 cycles, achieving an ultralow decay rate of 0.01%. The corresponding K‐ion full cell is also prepared, as expected, and shows stable capacity retention.
Associations between early marriage and preterm delivery: Evidence from lowland Nepal
Authors: Miller Faith A. , Marphatia Akanksha A. , Wells Jonathan C. , Cortina‐Borja Mario , Manandhar Dharma S. , Saville Naomi M. 
Published: December 2021

AbstractObjectivesPreterm delivery (<37 weeks gestation) is the largest cause of child mortality worldwide. Marriage and pregnancy during adolescence have been associated with an increased risk of preterm delivery. We investigate independent associations of age at marriage and age at first pregnancy with preterm delivery in a cohort of women from rural lowland Nepal.MethodsWe analyzed data from 17 974 women in the Low Birth Weight South Asia Trial. Logistic regression models tested associations of age at marriage and age at first pregnancy with preterm delivery, for primigravida (n = 6 243) and multigravida (n = 11 731) women. Models were adjusted for maternal education, maternal caste, and household asset score.ResultsNinety percent of participants had married at <18 years and 58% had their first pregnancy at <18 years. 20% of participants delivered preterm. Primigravida participants married at ≤14 years had higher odds of preterm delivery than those married ≥18 years, when adjusting for study design (adjusted odds ratio (aOR) 1.45, 95% CI: 1.15–1.83), confounders (aOR 1.28: 1.01–1.62) and confounders + age at pregnancy (aOR 1.29: 1.00–1.68). Associations were insignificant for multigravida women. No significant associations were observed between age at first pregnancy and preterm delivery.DiscussionIn this population, early marriage, rather than pregnancy, is a risk factor for preterm delivery. We hypothesize that psychological stress, a driver of preterm delivery which is increased among those marrying young, rather than physiological immaturity, drives this association. Further research into the psychological consequences of child marriage in Nepal is needed.