bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perovskite Single Crystals: Synthesis, Optoelectronic Properties, and Application
Authors: Li Junyu , Han Zeyao , Gu Yu , Yu Dejian , Liu Jiaxin , Hu Dawei , Xu Xiaobao , Zeng Haibo 
Published: December 2020

AbstractRecently, lead halide perovskite (PVSK) polycrystalline films have drawn much attention as photoactive material and scored tremendous achievements in solar cells, photodetectors, light‐emitting diodes, and lasers owing to their engrossing optoelectronic properties and facile solution‐processed fabrication. However, large amounts of grain boundaries unfavorably induce ion migration, surface defect, and poor stability, impeding PVSK polycrystalline film‐based optoelectronic devices from practical application. In comparison with the polycrystalline counterparts, PVSK single crystals (SCs) with lower trap density serve as a better platform for not only fundamental research but also device applications. In light of this, the idea of using PVSK single crystals (SCs) to construct the optoelectronic devices is then proposed. Since then, a series of synthesis methods of PVSK SCs have emerged. In this review, recent progress of synthesis method of PVSK SCs is tried to be summarized and their advantages and limitations are analyzed. And then, the optoelectronic properties including carrier dynamic, defects, ion migration, and instability issues in these 3D and 2D PVSK SCs are overviewed and accordingly the proper device configurations of corresponding solar cells, photodetectors, X‐ray, γ‐ray detectors, etc., are proposed. It is believed that this review can provide the guidance for the further development of PVSK SCs and their applications.
Recent Advances in 2D Rare Earth Materials
Authors: Chen Ping , Han Wei , Zhao Mei , Su Jianwei , Li Zexin , Li Dongyan , Pi Lejing , Zhou Xing , Zhai Tianyou 
Published: December 2020

Abstract2D rare earth (RE) materials have received considerable attention in recent years due to the fascinating luminescence, magnetism, and electric properties originated from RE associated with sharp and various emission peaks, intrinsic 2D ferromagnetism, and incommensurate charge density wave. These materials might open up a new prospect in next‐generation lighting, magnetic devices, and phototransistors. Herein, a comprehensive review of 2D RE materials is presented, focusing on their recent progresses. First, the crystal structures of 2D RE materials are discussed. Then, typical synthesis methods such as mechanical exfoliation, molecular beam epitaxy, pulsed laser deposition, and chemical vapor deposition are introduced. Furthermore, various properties in luminescence, magnetism, and electronics are summarized. The recently reported RE‐based 2D novel photodetectors are outlined as three constructions: MoS2/RE, graphene/RE, and perovskite/RE, which show promising applications for both narrow and broad band detection arised from the special absorption windows of different RE elements. Finally, the conclusions and outlook of this area are proposed, such as exploring novel 2D RE compounds, improving stability, and broadening applications.
Development of Electrocatalysts for Efficient Nitrogen Reduction Reaction under Ambient Condition
Authors: Liu Dong , Chen Mingpeng , Du Xinyu , Ai Haoqiang , Lo Kin Ho , Wang Shuangpeng , Chen Shi , Xing Guichuan , Wang Xuesen , Pan Hui 
Published: December 2020

AbstractAs one of the most important chemicals and an energy carrier, synthetic ammonia has been widely studied to meet the increasing demand. Among various strategies, electrochemical nitrogen reduction reaction (e‐NRR) is a promising way because of its green nature and easy set‐up on large‐scale. However, its practical application is extremely limited because of the very‐low production rate, which is strongly dependent on the electrocatalysts used. Therefore, searching novel efficient electrocatalysts for e‐NRR is essential to promote the technology. In this review, it highlights the insights on the mechanism for the NH3 electrochemical synthesis, recommend a reliable protocol for the ammonia detection, and systematically summarize the recent development on novel electrocatalysts, including noble metal‐based materials, single‐metal‐atom catalysts, non‐noble metal, and their compounds, and metal‐free materials, for efficient e‐NRR in both experimental and theoretical studies. Various strategies to improve the catalytic performance by increasing exposed active sites or tuning electronic structures, including surface control, defect engineering, and hybridization, are carefully discussed. Finally, perspectives and challenges are outlined. It can be expected that this review provides insightful guidance on the development of advanced catalytic systems to produce ammonia through N2 reduction.
Barnacle Cement Proteins‐Inspired Tough Hydrogels with Robust, Long‐Lasting, and Repeatable Underwater Adhesion
Authors: Fan Hailong , Wang Jiahui , Gong Jian Ping 
Published: December 2020

AbstractThe development of adhesives that can achieve robust and repeatable adhesion to various surfaces underwater is promising; however, this remains a major challenge primarily because the surface hydration layer weakens the interfacial molecular interactions. Herein, a strategy is proposed to develop tough hydrogels that are robust, reusable, and long‐lasting for underwater adhesion. Hydrogels from cationic and aromatic monomers with an aromatic‐rich composition inspired by the amino acid residuals in barnacle cement proteins are synthesized. The hydrogels are mechanically strong and tough (elastic modulus 0.35 MPa, fracture stress 1.0 MPa, and fracture strain 720%), owing to the interchain π–π and cation–π interactions. In water, the hydrogels firmly adhere to diverse surfaces through interfacial electrostatic and hydrophobic interactions (adhesion strength of 180 kPa), which allows for instant adhesion and reversibility (50 times). Moreover, the hydrogel shows long‐lasting adhesion in water for months (100 days). Novel adhesive hydrogels may be useful in many applications, including underwater transfer, water‐based devices, underwater repair, and underwater soft robots.
Discovery of a Novel Polymer for Xeno‐Free, Long‐Term Culture of Human Pluripotent Stem Cell Expansion
Authors: Nasir Aishah , Thorpe Jordan , Burroughs Laurence , Meurs Joris , Pijuan‐Galito Sara , Irvine Derek J. , Alexander Morgan R. , Denning Chris 
Published: December 2020

AbstractHuman pluripotent stem cells (hPSCs) can be expanded and differentiated in vitro into almost any adult tissue cell type, and thus have great potential as a source for cell therapies with biomedical application. In this study, a fully‐defined polymer synthetic substrate is identified for hPSC culture in completely defined, xenogenic (xeno)‐free conditions. This system can overcome the cost, scalability, and reproducibility limitations of current hPSC culture strategies, and facilitate large‐scale production. A high‐throughput, multi‐generational polymer microarray platform approach is used to test over 600 unique polymers and rapidly assess hPSC‐polymer interactions in combination with the fully defined xeno‐free medium, Essential 8 (E8). This study identifies a novel nanoscale phase separated blend of poly(tricyclodecane‐dimethanol diacrylate) and poly(butyl acrylate) (2:1 v/v), which supports long‐term expansion of hPSCs and can be readily coated onto standard cultureware. Analysis of cell‐polymer interface interactions through mass spectrometry and integrin blocking studies provides novel mechanistic insight into the role of the E8 proteins in promoting integrin‐mediated hPSC attachment and maintaining hPSC signaling, including ability to undergo multi‐lineage differentiation. This study therefore identifies a novel substrate for long‐term serial passaging of hPSCs in serum‐free, commercial chemically‐defined E8, which provides a promising and economic hPSC expansion platform for clinical‐scale application.
A Library of Atomically Thin 2D Materials Featuring the Conductive‐Point Resistive Switching Phenomenon
Authors: Ge Ruijing , Wu Xiaohan , Liang Liangbo , Hus Saban M. , Gu Yuqian , Okogbue Emmanuel , Chou Harry , Shi Jianping , Zhang Yanfeng , Banerjee Sanjay K. , Jung Yeonwoong , Lee Jack C. , Akinwande Deji 
Published: December 2020

AbstractNon‐volatile resistive switching (NVRS) is a widely available effect in transitional metal oxides, colloquially known as memristors, and of broad interest for memory technology and neuromorphic computing. Until recently, NVRS was not known in other transitional metal dichalcogenides (TMDs), an important material class owing to their atomic thinness enabling the ultimate dimensional scaling. Here, various monolayer or few‐layer 2D materials are presented in the conventional vertical structure that exhibit NVRS, including TMDs (MX2, M = transitional metal, e.g., Mo, W, Re, Sn, or Pt; X = chalcogen, e.g., S, Se, or Te), TMD heterostructure (WS2/MoS2), and an atomically thin insulator (h‐BN). These results indicate the universality of the phenomenon in 2D non‐conductive materials, and feature low switching voltage, large ON/OFF ratio, and forming‐free characteristic. A dissociation–diffusion–adsorption model is proposed, attributing the enhanced conductance to metal atoms/ions adsorption into intrinsic vacancies, a conductive‐point mechanism supported by first‐principle calculations and scanning tunneling microscopy characterizations. The results motivate further research in the understanding and applications of defects in 2D materials.
Enhanced Capture of Broadband Solar‐Blind UV Light via Introducing Alkali‐Metal Ions (Li+, Na+, and K+) into DC Spectral Converter
Authors: Jia Hong , Li Xue , An Ximei , Chang Shasha , Liu Zhongli , Peng Feng , Liu Xiaofeng , Gao Linhui , Zhou Shifeng , Qiu Jianrong 
Published: December 2020

AbstractRare earth doped down‐conversion (DC) materials, due to their unique spectral conversion characteristics, are promising candidates for narrow band solar‐blind ultraviolet (UV) light detection devices. Herein, an enhanced capture device for broadband solar‐blind UV light is constructed by combining an ordinary semiconductor with a DC spectrum converter, the essence of which is to introduce the appropriate alkali‐metal ions (Li+, Na+, and K+) into DC layer. Europium‐doped organic–inorganic composite films are used as spectral converters because of their excellent DC characteristic, which can convert broadband solar‐blind UV incident illumination into visible light suitable for capture by light dependent resistor (LDR). Interestingly, the spectral conversion efficiency is positively correlated with the capture ability of broadband solar‐blind UV photons. The introduction of alkali‐metal ions in the DC layer enhances the photon detection efficiency with an increase rate of around 200%, which is attributed to alkali‐metal ions changing the local crystal field symmetry around the Eu3+emitter and distorting the matrix crystal of Y2O3, thus increasing the probability of intra‐4felectron transition. These results signify that the present rare‐earth doped DC luminescent materials are promising building blocks for assembly of high‐performance broadband solar‐blind UV detector.
Bacterium‐Inspired Nanoagents Armed with On‐Switch of Immune Recruitment and Immune Activation
Authors: Li Chu‐Xin , Zhang Yu , Qi Yong‐Dan , Liu Miao‐Deng , Li Bin , Zhang Ming‐Kang , Feng Jun , Zhang Xian‐Zheng 
Published: December 2020

AbstractBacterium‐based immunotherapy holds promise for tumor eradication, yet its application is hindered by significant safety concerns. Inspired bacteria, an immunity‐switch nanotherapeutic termed FMaP, for precise immunity control is developed. This nanotherapeutic remains immunologically inert (immunity‐off) during its circulation period but elicits immune‐associated activity (immunity‐on) upon reaching tumors. The FMaP nanoconstruction is composed of 1) a magnetic nanoparticle (MNP) nanocore, 2) a bacteria‐derived chemotactic peptide conjugated onto MNP, and 3) a bacterial capsule‐like polyethylene glycol (PEG) corona coupled via a tumor‐labile linkage. The PEG corona acts as the off–on switch to enable FMaP immune‐off under normal conditions. Upon magnetotactic entry into acid tumors, the PEG corona can escape to expose the chemotactic peptide, functioning as the on‐switch to initiate immunoregulation of intratumoral immune cells and site‐specific recruitment of circulating immune cells. Compared with the performance of bacteria, FMaP shares most of their immune features but avoids their toxicity. FMaP demonstrates high immunotherapeutic potency either alone or in combination with chemotherapy and immune checkpoint blockade therapy toward colon carcinoma and melanoma tumor models, showing versatile adaptability for treating multiple tumor types. This study offers a paradigm of how to rationally design materials by seeking advantages from micro‐organisms.
Multifunctional Nanotheranostic Agent for NIR‐II Imaging‐Guided Synergetic Photothermal/Photodynamic Therapy
Authors: Li Tuanwei , Liu Le , Xu Pengping , Yuan Pan , Tian Youliang , Cheng Quan , Yan Lifeng 
Published: December 2020

AbstractAll‐in‐one phototheranostics triggered by near‐infrared (NIR) light are receiving significant attention. Herein, an NIR (NIR‐I) probe with intrinsic multifunctionality is synthesized and encapsulated by an amphiphilic polypeptide P(OEGMA)21‐P(Asp)16. The as‐fabricated polymeric micelles (P@BDP) serve as an NIR‐II imaging‐guided nanotheranostic platform for NIR‐I photothermal therapy (PTT) and photodynamic therapy (PDT). The P@BDP exhibit excellent photostability and equally outstanding photothermal conversion efficiency upon irradiation with a 730 nm laser (40.1%) or 808 nm laser (42.0%), yet significantly superior reactive oxygen species production capability under 730 nm laser irradiation. In vivo studies reveal that the capillary vessel of the mouse can be unambiguously detected and the accumulation of P@BDP in tumors can be monitored in real‐time by NIR‐II fluorescence imaging. Synergistic phototherapy (730 nm) can provide a highly desirable therapeutic effect under NIR‐II imaging‐guided PTT/PDT combination therapy.
Silver‐Nanowire‐Embedded Photopolymer Films for Transparent Film Heaters with Ultra‐Flexibility, Quick Thermal Response, and Mechanical Reliability
Authors: Jin In Su , Choi Jun , Jung Jae Woong 
Published: December 2020

AbstractA novel approach to fabricate mechanically robust and flexible transparent film heaters (TFHs) in which a highly conductive silver nanowire (Ag NWs) network is sandwiched by photo‐curable polymer layers is demonstrated. The photopolymer provides an excellent platform as a substrate and a passivation layer of the solution‐processed Ag NWs network due to its favorable optical and mechanical properties. The flexible TFHs exhibit excellent heat‐generating properties, reaching to >130 °C within 15 s at a driving voltage of 4 V. The unique bilayer structure also provides an important role for protecting the Ag NWs network from external stimuli, such as waterproof properties, physical damages, and ambient moisture, which promises practical wearable, medical, or industrial heating applications.
Partially Oxidized MXene Ti3C2Tx Sheets for Memristor having Synapse and Threshold Resistive Switching Characteristics
Authors: Sokolov Andrey , Ali Mumtaz , Li Hui , Jeon Yu‐Rim , Ko Min Jae , Choi Changhwan 
Published: December 2020

AbstractTransition metal carbides, called MXenes, can be used for MXene‐based unique electronic devices such as new types of batteries, energy storage devices, and supercapacitors, where MXene is used as an electrode. The unique surface properties of MXene and 2D structure can be further applied to the new electronic devices. In this paper, the unique insulating properties of partially oxidized MXene (Ti3C2Tx) sheets are utilized for memory storage and electronic synapse applications. The device exhibits threshold resistive switching characteristics based on Ag+ migration dynamics. It is found that this Ag+ cation migration is similar to Ca2+ ion dynamics of a biological synapse, and thus, biological synapse functions such as intrusion/extrusion of Ag+ cation, paired‐pulse facilitation (PPF), post‐tetanic potentiation (PTP), short‐term potentiation (STP), and transition of STP to long‐term potentiation (LTP) are well‐emulated. It is believed that this device development can be potentially used in the next‐generation hardware‐based artificial intelligence systems.
Near‐Unity Molecular Doping Efficiency in Monolayer MoS2
Authors: Yarali Milad , Zhong Yiren , Reed Serrae N. , Wang Juefan , Ulman Kanchan A. , Charboneau David J. , Curley Julia B. , Hynek David J. , Pondick Joshua V. , Yazdani Sajad , Hazari Nilay , Quek Su Ying , Wang Hailiang , Cha Judy J. 
Published: December 2020

AbstractSurface functionalization with organic electron donors (OEDs) is an effective doping strategy for 2D materials, which can achieve doping levels beyond those possible with conventional electric field gating. While the effectiveness of surface functionalization has been demonstrated in many 2D systems, the doping efficiencies of OEDs have largely been unmeasured, which is in stark contrast to their precision syntheses and tailored redox potentials. Here, using monolayer MoS2 as a model system and an organic reductant based on 4,4′‐bipyridine (DMAP‐OED) as a strong organic dopant, it is established that the doping efficiency of DMAP‐OED to MoS2 is in the range of 0.63 to 1.26 electrons per molecule. The highest doping levels to date are also achieved in monolayer MoS2 by surface functionalization and demonstrate that DMAP‐OED is a stronger dopant than benzyl viologen, which is the previous best OED dopant. The measured range of the doping efficiency is in good agreement with the values predicted from first‐principles calculations. This work provides a basis for the rational design of OEDs for high‐level doping of 2D materials.
Recent Progress and Challenges toward Highly Stable Nonfullerene Acceptor‐Based Organic Solar Cells
Authors: Wang Yiwen , Lee Jinho , Hou Xueyan , Labanti Chiara , Yan Jun , Mazzolini Eva , Parhar Amber , Nelson Jenny , Kim Ji‐Seon , Li Zhe 
Published: December 2020

AbstractOrganic solar cells (OSCs) based on nonfullerene acceptors (NFAs) have made significant breakthrough in their device performance, now achieving a power conversion efficiency of ≈18% for single junction devices, driven by the rapid development in their molecular design and device engineering in recent years. However, achieving long‐term stability remains a major challenge to overcome for their commercialization, due in large part to the current lack of understanding of their degradation mechanisms as well as the design rules for enhancing their stability. In this review, the recent progress in understanding the degradation mechanisms and enhancing the stability of high performance NFA‐based OSCs is a specific focus. First, an overview of the recent advances in the molecular design and device engineering of several classes of high performance NFA‐based OSCs for various targeted applications is provided, before presenting a critical review of the different degradation mechanisms identified through photochemical‐, photo‐, and morphological degradation pathways. Potential strategies to address these degradation mechanisms for further stability enhancement, from molecular design, interfacial engineering, and morphology control perspectives, are also discussed. Finally, an outlook is given highlighting the remaining key challenges toward achieving the long‐term stability of NFA‐OSCs.
Unraveling the Mechanisms of Lithium Metal Plating/Stripping via In Situ/Operando Analytical Techniques
Authors: Um Ji Hyun , Yu Seung‐Ho 
Published: December 2020

AbstractLithium, the lightest metal with the lowest standard reduction potential, has been long considered as the ultimate anode material for next‐generation high‐energy‐density batteries. However, an unexpected Li dendrite formation, which causes poor reversibility of electrochemical reactions and safety concerns, is a major problem that has to be solved for the commercialization of Li metal anodes. For the implementation of stable Li metal anodes, complete understanding on the dendritic Li formation and its dissolution is essential for electrode material design, which requires the development of advanced characterization techniques. Specifically, compared to an ex situ characterization as a postmortem analysis, in situ/operando characterizations allow dynamic structural and chemical evolution to be directly observed in a realistic battery cell, which helps unravel the complex reactions and degradation mechanisms in Li metal anodes. Here, recent progress in the understanding of electrochemical behavior in Li metal anodes upon deposition and dissolution, verified by the in situ/operando analytical techniques using light, electron, X‐ray, neutron, and magnetism‐based characterizations, is covered. This progress report provides a fundamental understanding of Li deposition and dissolution mechanisms and highlights the critical role of in situ/operando analyses in developing stable Li metal anodes.
Extending the Performance Limit of Anodes: Insights from Diffusion Kinetics of Alloying Anodes
Authors: Choi Yong‐Seok , Scanlon David O. , Lee Jae‐Chul 
Published: December 2020

AbstractAlloying anodes have long attracted attention as promising candidate electrodes for application in grid‐level energy storage systems owing to their high energy capacity. Alloying anode‐based batteries, however, remain far from practical applications, which require several issues affecting cell performance to be addressed. The large volumetric expansion of anodes and associated phenomena that occur during battery cycling are the main reasons for the poor electrochemical performance of alloying anodes. These electrochemical behaviors of alloying anodes originate from the reactions between the unreacted anode material and inflowing carrier ions. Thus, the diffusion kinetics play a key role in determining the electrochemical properties of alloying anodes. Recent advances in analytical instruments and atomic simulations offer new approaches for interpreting anode performance. Beginning with a brief historical background, this review presents an overview of the origin of diffusion kinetics and how this concept has been extended to alloying anodes. Accordingly, the relationship between the diffusion kinetics and electrochemical performance of alloying anodes is discussed, combined with efficient strategies that can be adopted to improve electrochemical properties. Finally, a design overview of next‐generation alloying anodes that can extend the batteries’ performance limit is proposed.