bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced Hole‐Carrier Selectivity in Wide Bandgap Halide Perovskite Photovoltaic Devices for Indoor Internet of Things Applications
Authors: Lee Minwoo , Choi Eunyoung , Soufiani Arman Mahboubi , Lim Jihoo , Kim Moonyong , Chen Daniel , Green Martin Andrew , Seidel Jan , Lim Sean , Kim Jincheol , Dai Xinchen , Lee‐Chin Robert , Zheng Bolin , Hameiri Ziv , Park Jongsung , Hao Xiaojing , Yun Jae Sung 
Published: February 2021

AbstractHalide perovskite‐based photovoltaic (PV) devices have recently emerged for low energy consumption electronic devices such as Internet of Things (IoT). In this work, an effective strategy to form a hole‐selective layer using phenethylammonium iodide (PEAI) salt is presented that demonstrates unprecedently high open‐circuit voltage of 0.9 V with 18 µW cm−2 under 200 lux (cool white light‐emitting diodes). An appropriate post‐deposited amount of PEAI (2 mg) strongly interacts with the perovskite surface forming a conformal coating of PEAI on the perovskite film surface, which improves the crystallinity and absorption of the film. Here, Kelvin probe force microscopy results indicate the diminished potential difference across the grain boundaries and grain interiors after the PEAI deposition, constructing an electrically and chemically homogeneous surface. Also, the surface becomes more p‐type with a downshift of a valence band maximum, confirmed by ultraviolet photoelectron spectroscopy measurement, facilitating the transport of holes to the hole transport layer (HTL). The hole‐selective layer‐deposited devices exhibit reduced hysteresis in light current density–voltage curves and maintain steadily high fill factor across the different light intensities (200–1000 lux). This work highlights the importance of the HTL/perovskite interface that prepares the indoor halide perovskite PV devices for powering IoT device.
Direct Observation of Fe‐Ge Ordering in Fe5−xGeTe2 Crystals and Resultant Helimagnetism
Authors: Ly Trinh Thi , Park Jungmin , Kim Kyoo , Ahn Hyo‐Bin , Lee Nyun Jong , Kim Kwangsu , Park Tae‐Eon , Duvjir Ganbat , Lam Nguyen Huu , Jang Kyuha , You Chun‐Yeol , Jo Younghun , Kim Se Kwon , Lee Changgu , Kim Sanghoon , Kim Jungdae 
Published: February 2021

AbstractMicroscopic structures and magnetic properties are investigated for Fe5−xGeTe2 single crystal, recently discovered as a promising van der Waals (vdW) ferromagnet. An Fe atom (Fe(1)) located in the outermost Fe5Ge sublayer has two possible split‐sites which are either above or below the Ge atom. Scanning tunneling microscopy shows √3 × √3 superstructures which are attributed to the ordering of Fe(1) layer. The √3 × √3 superstructures have two different phases due to the symmetry of Fe(1) ordering. Intriguingly, the observed √3 × √3 ordering breaks the inversion symmetry of crystal, resulting in substantial antisymmetric exchange interaction. The temperature dependence of magnetization reveals a sharp magnetic anomaly suggesting helical magnetism of the Fe5−xGeTe2 due to its non‐centrosymmetricity. Analytical study also supports that the observed ordering can give rise to the helimagnetism. The work will provide essential information to understand the complex magnetic properties and the origin of the new vdW ferromagnet, Fe5−xGeTe2 for future topology‐based spin devices.
Ultra‐Sensitive and Stretchable Ionic Skins for High‐Precision Motion Monitoring
Authors: Kim Jeong Hui , Cho Kyung Gook , Cho Dae Hyun , Hong Kihyon , Lee Keun Hyung 
Published: February 2021

AbstractStretchability and sensitivity are essential properties of wearable electronics for effective motion monitoring. In general, increasing the sensitivity of strain sensors based on ionic conductors trades off elasticity, which results in low sensitivity of the strain sensors at large mechanical deformations. To address this, ion‐permeable conducting polymer electrodes with low contact resistance are utilized in ionic gel‐based strain sensors. Using a rectangular‐shaped ionic gel and ion‐permeable electrodes significantly increase the gauge factor of the strain sensor, similar to the theoretical value at a given strain. To further increase the sensitivity of the strain sensor, the ionic gel is patterned with zigzagged tracks that gap apart as the gel stretches, and the gaps close as the gel contracts, leading to a large variation in the relative resistance upon stretching. By combining the zigzagged ionic gel and the ion‐permeable electrodes, highly sensitive stretchable sensors are realized with a record‐high gauge factor of 173, compared to existing ionic conductor‐based stretchable strain sensors. The zigzag‐patterned ionic sensor can successfully monitor various motions when attached to the human body. These results are expected to afford promising strategies for developing highly sensitive, stretchable sensing systems for E‐skin sensors and soft robotics.
Epitaxial Growth of 2D Bi2O2Se Nanoplates/1D CsPbBr3 Nanowires Mixed‐Dimensional Heterostructures with Enhanced Optoelectronic Properties
Authors: Fan Chao , Dai Beibei , Liang Huikang , Xu Xing , Qi Zhuodong , Jiang Haotian , Duan Huigao , Zhang Qinglin 
Published: February 2021

AbstractThe 2D/1D mixed‐dimensional van der Waals heterostructures have great potential for electronics and optoelectronics with high performance and multifunctionality. The epitaxy of 1D micro/nanowires on 2D layered materials may efficiently realize the large‐scale preparation of 2D/1D heterostructures, which is critically important for their practical applications. So far, however, only the wires of Bi2S3, Te, and Sb2Se3 have been epitaxially grown on MoS2 or WS2. Here, it is reported that the epitaxial growth of 1D CsPbBr3 nanowires on 2D Bi2O2Se nanoplates through a facile vertical vapor deposition method. The CsPbBr3 wires are well aligned on the Bi2O2Se plates in fourfold symmetry with the epitaxial relationships of [001]CsPbBr3||[200]Bi2O2Se and [1‐10]CsPbBr3||[020]Bi2O2Se. The photoluminescence results reveal that the emission from CsPbBr3 is significantly quenched in the heterostructure, which implies the charge carriers transfer from CsPbBr3 to Bi2O2Se. The waveguide characterization shows that the epitaxial CsPbBr3 wires may efficiently confine and guide their emission, which favors the light absorption of Bi2O2Se. Importantly, the photocurrent mapping and spectra of the devices based on these 2D/1D heterostructures prove that the epitaxial CsPbBr3 wires remarkably enhances the photoresponse of Bi2O2Se, which indicates these heterostructures can be applied in high‐performance optoelectronic devices or on‐chip integrated photonic circuits.
Thermal Controlled Tunable Adhesive for Deterministic Assembly by Transfer Printing
Authors: Luo Hongyu , Wang Suhao , Wang Chengjun , Linghu Changhong , Song Jizhou 
Published: February 2021

AbstractTransfer printing techniques based on tunable adhesives that enable heterogeneous integration of materials in desired layouts are essential for developing existing and envisioned systems such as flexible electronics and micro‐LED (µ‐LED) displays. Here, a novel thermal controlled tunable adhesive, which not only has the ability of eliminating the interfacial adhesion for printing but also provides a new strategy for enhancing the interfacial adhesion for pick‐up is reported. The tunable adhesive features cavities filled with air on the surface. This simple construct offers thermal controlled suction and thrust with their amplitudes on the order of a few tens of kPa within 100 °C temperature change, which enables a reliable damage‐free transfer printing. Systematically theoretical and experimental studies reveal the underlying thermal induced pressure change mechanism and provide insights into the design and operation of the thermal controlled tunable adhesive. Demonstrations of this smart adhesive in manipulation of various surfaces and transfer printing of micro‐scale Si inks and µ‐LEDs illustrate its unusual capabilities for deterministic assembly by transfer printing.
Current‐Induced Spin Torques on Single GdFeCo Magnetic Layers
Authors: Céspedes‐Berrocal David , Damas Heloïse , Petit‐Watelot Sébastien , Maccariello Davide , Tang Ping , Arriola‐Córdova Aldo , Vallobra Pierre , Xu Yong , Bello Jean‐Loïs , Martin Elodie , Migot Sylvie , Ghanbaja Jaafar , Zhang Shufeng , Hehn Michel , Mangin Stéphane , Panagopoulos Christos , Cros Vincent , Fert Albert , Rojas‐Sánchez Juan‐Carlos 
Published: February 2021

AbstractSpintronics exploit spin‐orbit coupling (SOC) to generate spin currents, spin torques, and, in the absence of inversion symmetry, Rashba and Dzyaloshinskii–Moriya interactions. The widely used magnetic materials, based on 3d metals such as Fe and Co, possess a small SOC. To circumvent this shortcoming, the common practice has been to utilize the large SOC of nonmagnetic layers of 5d heavy metals (HMs), such as Pt, to generate spin currents and, in turn, exert spin torques on the magnetic layers. Here, a new class of material architectures is introduced, excluding nonmagnetic 5d HMs, for high‐performance spintronics operations. Very strong current‐induced torques exerted on single ferrimagnetic GdFeCo layers, due to the combination of large SOC of the Gd 5d states and inversion symmetry breaking mainly engineered by interfaces, are demonstrated. These “self‐torques” are enhanced around the magnetization compensation temperature and can be tuned by adjusting the spin absorption outside the GdFeCo layer. In other measurements, the very large emission of spin current from GdFeCo, 80% (20%) of spin anomalous Hall effect (spin Hall effect) symmetry is determined. This material platform opens new perspectives to exert “self‐torques” on single magnetic layers as well as to generate spin currents from a magnetic layer.
Unveiling the Local Atomic Arrangements in the Shear Band Regions of Metallic Glass
Authors: Mu Xiaoke , Chellali Mohammed Reda , Boltynjuk Evgeniy , Gunderov Dmitry , Valiev Ruslan Z. , Hahn Horst , Kübel Christian , Ivanisenko Yulia , Velasco Leonardo 
Published: February 2021

AbstractThe prospective applications of metallic glasses are limited by their lack of ductility, attributed to shear banding inducing catastrophic failure. A concise depiction of the local atomic arrangement (local atomic packing and chemical short‐range order), induced by shear banding, is quintessential to understand the deformation mechanism, however still not clear. An explicit view of the complex interplay of local atomic structure and chemical environment is presented by mapping the atomic arrangements in shear bands (SBs) and in their vicinity in a deformed Vitreloy 105 metallic glass, using the scanning electron diffraction pair distribution function and atom probe tomography. The results experimentally prove that plastic deformation causes a reduction of geometrically favored polyhedral motifs. Localized motifs variations and antisymmetric (bond and chemical) segregation extend for several hundred nanometers from the SB, forming the shear band affected zones. Moreover, the variations within the SB are found both perpendicular and parallel to the SB plane, also observable in the oxidation activity. The knowledge of the structural–chemical changes provides a deeper understanding of the plastic deformation of metallic glasses especially for their functional applications and future improvements.
Sandwich‐Like Heterostructures of MoS2/Graphene with Enlarged Interlayer Spacing and Enhanced Hydrophilicity as High‐Performance Cathodes for Aqueous Zinc‐Ion Batteries
Authors: Li Shengwei , Liu Yongchang , Zhao Xudong , Shen Qiuyu , Zhao Wang , Tan Qiwei , Zhang Ning , Li Ping , Jiao Lifang , Qu Xuanhui 
Published: February 2021

AbstractLayered materials have great potential as cathodes for aqueous zinc‐ion batteries (AZIBs) because of their facile 2D Zn2+ transport channels; however, either low capacity or poor cycling stability limits their practical applications. Herein, two classical layered materials are innovatively combined by intercalating graphene into MoS2 gallery, which results in significantly enlarged MoS2 interlayers (from 0.62 to 1.16 nm) and enhanced hydrophilicity. The sandwich‐structured MoS2/graphene nanosheets self‐assemble into a flower‐like architecture that facilitates Zn‐ion diffusion, promotes electrolyte infiltration, and ensures high structural stability. Therefore, this novel MoS2/graphene nanocomposite exhibits exceptional high‐rate capability (285.4 mA h g−1 at 0.05 A g−1 with 141.6 mA h g−1 at 5 A g−1) and long‐term cycling stability (88.2% capacity retention after 1800 cycles). The superior Zn2+ migration kinetics and desirable pseudocapacitive behaviors are confirmed by electrochemical measurements and density functional theory computations. The energy storage mechanism regarding the highly reversible phase transition between 2H‐ and 1T‐MoS2 upon Zn‐ion insertion/extraction is elucidated through ex situ investigations. As a proof of concept, a flexible quasi‐solid‐state zinc‐ion battery employing the MoS2/graphene cathode demonstrates great stability under different bending conditions. This study paves a new direction for the design and on‐going development of 2D materials as high‐performance cathodes for AZIBs.
Layered Heterostructure Ionogel Electrolytes for High‐Performance Solid‐State Lithium‐Ion Batteries
Authors: Hyun Woo Jin , Thomas Cory M. , Luu Norman S. , Hersam Mark C. 
Published: February 2021

AbstractIonogel electrolytes based on ionic liquids and gelling matrices offer several advantages for solid‐state lithium‐ion batteries, including nonflammability, wide processing compatibility, and favorable electrochemical and thermal properties. However, the absence of ionic liquids that are concurrently stable at low and high potentials constrains the electrochemical windows of ionogel electrolytes and thus their high‐energy‐density applications. Here, ionogel electrolytes with a layered heterostructure are introduced, combining high‐potential (anodic stability: >5 V vs Li/Li+) and low‐potential (cathodic stability: <0 V vs Li/Li+) imidazolium ionic liquids in a hexagonal boron nitride nanoplatelet matrix. These layered heterostructure ionogel electrolytes lead to extended electrochemical windows, while preserving high ionic conductivity (>1 mS cm−1 at room temperature). Using the layered heterostructure ionogel electrolytes, full‐cell solid‐state lithium‐ion batteries with a nickel manganese cobalt oxide cathode and a graphite anode are demonstrated, exhibiting voltages that are unachievable with either the high‐potential or low‐potential ionic liquid alone. Compared to ionogel electrolytes based on mixed ionic liquids, the layered heterostructure ionogel electrolytes enable higher stability operation of full‐cell lithium‐ion batteries, resulting in significantly enhanced cycling performance.
Functional Skeletal Muscle Regeneration with Thermally Drawn Porous Fibers and Reprogrammed Muscle Progenitors for Volumetric Muscle Injury
Authors: Jin Yoonhee , Shahriari Dena , Jeon Eun Je , Park Seongjun , Choi Yi Sun , Back Jonghyeok , Lee Hyungsuk , Anikeeva Polina , Cho Seung‐Woo 
Published: February 2021

AbstractSkeletal muscle has an inherent capacity for spontaneous regeneration. However, recovery after severe injuries such as volumetric muscle loss (VML) is limited. There is therefore a need to develop interventions to induce functional skeletal muscle restoration. One suggested approach includes tissue‐engineered muscle constructs. Tissue‐engineering treatments have so far been impeded by the lack of reliable cell sources and the challenges in engineering of suitable tissue scaffolds. To address these challenges, muscle extracellular matrix (MEM) and induced skeletal myogenic progenitor cells (iMPCs) are integrated within thermally drawn fiber based microchannel scaffolds. The microchannel fibers decorated with MEM enhance differentiation and maturation of iMPCs. Furthermore, engraftment of these bioengineered hybrid muscle constructs induce de novo muscle regeneration accompanied with microvessel and neuromuscular junction formation in a VML mouse model, ultimately leading to functional recovery of muscle activity.
Solid‐State Lithium Metal Batteries with Extended Cycling Enabled by Dynamic Adaptive Solid‐State Interfaces
Authors: Liu Shujie , Zhao Yun , Li Xiaohan , Yu Jianyong , Yan Jianhua , Ding Bin 
Published: February 2021

AbstractImproving the long‐term cycling stability of solid‐state lithium (Li)‐metal batteries (SSBs) is a severe challenge because of the notorious solid–solid interfacial contact loss originating from the repeated expansion and contraction of the Li anodes. Here, it is reported that high‐performance SSBs are enabled by constructing brick‐and‐mortar electrolytes that can dynamically adapt to the interface changes during cycling. An electrolyte film with a high mechanical strain (250%) is fabricated by filling viscoelastic (600% strain) and piezoelectric block‐copolymer electrolytes (mortar) into a mixed conductor Li0.33La0.56TiO3‐x nanofiber film (brick). During Li‐plating, the electrolytes can homogenize the interfacial electric field and generate piezoelectricity to promote uniform Li‐deposition, while the mortar can adhere to the Li‐anode without interfacial disintegration in the reversed Li‐stripping. As a result, the electrolytes show excellent compatibility with the electrodes, leading to a long electrochemical cyclability at room temperature. The symmetrical Li//Li cells run stably for 1880 h without forming dendrites, and the LiFePO4/Li full batteries deliver high coulombic efficiency (>99.5%) and capacity retention (>85%) over 550 cycles. More practically, the pouch cells exhibit excellent flexibility and safety for potential practical applications.
Atomistic Site Control of Pd in Crystalline MnO2 Nanofiber for Enhanced Electrocatalysis
Authors: Liu Mengmeng , Hu Shang , Zhang Yaojia , Zhao Chuyi , Jiang Wenqian , Qi Chunhong , Zhu Xiaohang , Qiu Pengpeng , Sun Yu , Kato Kenichi , Zhao Yonghui , Li Xiaopeng , Yamauchi Miho , Luo Wei 
Published: February 2021

AbstractOxides supported precious metals have wide applications in (electro‐)catalysis. Although single atom dispersion is known as the most efficient metal utilization strategy, the dependence of the catalytic activity on different sites consisted of various anchoring sites for single atoms is largely unknown. Here, the electrocatalytic activities of crystalline α‐MnO2 with atomistic Pd locating at different sites including substitutional, tunnel, and surface‐bound sites are first predicted, and then experimentally validated by applying different synthetic methods including hydrothermal reaction and impregnation‐calcination. The quantum chemistry calculations together with experimental characterization suggest that substitutional Pd/MnO2 possesses higher activity than the other samples due to the favorable geometric and electronic structures. Substitutional Pd can work synergistically with vicinal Mn sites toward cleavage of OO bonds. This work provides a comprehensive understanding on the impact of atomistic anchoring site and advances the reliable control over the electrocatalytic performance of oxide‐supported single atoms.
High‐Sensitivity Profilometry for Measurement of Multilayer Structure with Low‐Coherence Composite Interferometer
Authors: Lin Yu‐Kai , Cheng Chi‐Chu , Hsu I‐Jen 
Published: February 2021

AbstractHigh‐sensitivity profilometry provides valuable tools for measurement of the surface structure of a device. On the other hand, tomographic techniques such as ultrasound imaging or optical coherence tomography can be used to measure the inner structure of a device with micrometer resolution. However, the multilayer structure of a device such as a display panel cannot be measured with nanometer sensitivity using conventional profilometry and tomographic techniques. For this purpose, a new type of profilometry based on the technique of low‐coherence composite interferometer is proposed and demonstrated. With the phase compensation mechanism of the technique, phase fluctuation resulted from the instability of scanning component and environment can be significantly reduced and a high axial sensitivity can be achieved. The technique is demonstrated by measuring nine interfaces of a display panel with a displacement sensitivity of 11.73 nm without requiring any preknowledge on the structure and has the potential to become a new technique for inspecting the multilayer structure of a packaged device in industry.
Near‐Infrared‐II Nanomaterials for Fluorescence Imaging and Photodynamic Therapy
Authors: Lin Hongxin , Lin Zexi , Zheng Konghua , Wang Chenlu , Lin Lisheng , Chen Jianxin , Song Jibin 
Published: February 2021

AbstractFluorescence (FL) imaging and photodynamic therapy (PDT) are popular in the diagnosis and treatment of diseases, respectively, especially in cancer. The excitation of the laser in the second near‐infrared (NIR‐II) window can effectively avoid the interference of spontaneous fluorescence and light scattering of tissues, obtaining high‐resolution images at deeper penetration depth. Due to their ideal spectral absorbance and high conversion efficiency, nanomaterials with emission at NIR‐II window not only overcome the absorption or emission of NIR‐II light by endogenous biomolecules, but also facilitate NIR‐II FL imaging and the application of photodynamic therapy (PDT). The research progress of NIR‐II nanomaterials for FL imaging and PDT in recent years is reviewed. First, the NIR‐II FL imaging of several representative organic and inorganic materials is introduced, including their remarkable properties and synthesis methods. Then, the use of NIR‐II nanomaterials in PDT, such as NIR‐II FL imaging‐guided PDT, and PDT combined with photothermal therapy is described. Finally, some critical challenges and open problems are proposed that need to be addressed in synthetic technology and clinical application.
Photoluminescence of Singlet/Triplet Self‐Trapped Excitons in Sb3+‐Based Metal Halides
Authors: Jing Yuyu , Liu Ying , Li Mingze , Xia Zhiguo 
Published: February 2021

AbstractEmerging lead‐free metal halides with low toxicity and unparalleled optoelectronic properties have attracted growing research interests, also demonstrating extensive application potentials. Among these, Sb3+‐based all‐inorganic/organic–inorganic hybrid metal halides become a vital group due to the special energy level distribution along with diverse optical properties. However, there remains a gap in understanding the relationship between the crystal structure and the radiation process of involved Sb3+ emission. Herein, the existing reports about Sb3+‐based luminescent metal halides are revisited and their structure–luminescence–application relationship is explored, and it is further established that the triplet self‐trapped excitons (STEs) emission of Sb3+ varies in different crystallographic environments and endows tunable luminescent performance. This work aims to provide constructive strategies in the further exploitation of Sb3+‐based metal halides, and also guides the structural design and photoluminescence tuning of doped metal halide materials.
Regio‐ and Stereoselective Synthesis of Rotationally Hindered C12‐Naphthylated Tribenzo[a,c,j]xanthenes through Catalytic Tricyclization of Yne‐Allenones
Authors: Zhu Shan‐Shan , Li Heng , Fu Rong , Hao Wen‐Juan , Wang Shu‐Liang , Tu Shu‐Jiang , Jiang Bo 
Published: February 2021

AbstractA Lewis acid‐catalyzed tricyclization of yne‐allenones with 1‐alkynylnaphthalen‐2‐ols has been developed, and used to produce a wide range of rotationally hindered tribenzo[a,c,j]xanthenes with generally good yields and stereoselectivity. This process involves a complex [2+2] cycloaddition relay and [4+2] cyclization cascade, enabling scission/recombination of C−C triple bonds to access unprecedented hexaheterocyclic architectures. The reaction also features good compatibility with different types of substituents, triple annulation cascade and the efficient control of regio‐ and stereochemistry.magnified image