bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature‐Mediated Engineering of Graphdiyne Framework Enabling High‐Performance Potassium Storage
Authors: Yi Yuyang , Li Jiaqiang , Zhao Wen , Zeng Zhihan , Lu Chen , Ren Hao , Sun Jingyu , Zhang Jin , Liu Zhongfan 
Published: June 2020

AbstractGraphdiyne (GDY), an emerging type of carbon allotropes, possesses fascinating electrical, chemical, and mechanical properties to readily spark energy applications in the realm of Li‐ion and Na‐ion batteries. Nevertheless, rational design of GDY architectures targeting advanced K‐ion storage has rarely been reported to date. Herein, the first example of synthesizing GDY frameworks in a scalable fashion to realize superb potassium storage for high‐performance K‐ion battery (KIB) anodes is showcased. To begin with, first principles calculations provide theoretical guidances for analyzing the intrinsic potassium storage capability of GDY. Meanwhile, the specific capacity is predicted to be as high as 620 mAh g−1, which is considerably augmented as compared with graphite (278 mAh g−1). Experimental tests then reveal that prepared GDY framework indeed harvests excellent electrochemical performance as a KIB anode, achieving high specific capacity (≈505 mAh g−1 at 50 mA g−1), outstanding rate performance (150 mAh g−1 at 5000 mA g−1) and favorable cycling stability (a high capacity retention of over 90% after 2000 cycles at 1000 mA g−1). Furthermore, kinetic analysis reveals that capacitive effect mainly accounts for the K‐ion storage, with operando Raman spectroscopy/ex situ X‐ray photoelectron spectroscopy identifying good electrochemical reversibility of GDY.
Flat Lenses Based on 2D Perovskite Nanosheets
Authors: Wang Ziyu , Yang Tieshan , Zhang Yupeng , Ou Qingdong , Lin Han , Zhang Qianhui , Chen Huanyang , Hoh Hui Ying , Jia Baohua , Bao Qiaoliang 
Published: June 2020

AbstractUltrathin flat lenses based on metasurfaces or metamaterials have shown great promise in recent years as essential components in nano‐optical system, with capability of abrupt changes of light wavefronts. However, such structural designs require complex nanopatterns and a time‐consuming nanofabrication process. In this regard, flat lenses are developed based on 2D perovskite nanosheets, using a cost‐effective mask‐free femtosecond direct laser writing system. The optical properties of the 2D perovskite are rationally adjusted through facile composition engineering as well as thickness‐dependent quantum‐size confinement. A diffraction theory model is derived to understand the focusing mechanism of the 2D perovskite nanosheets flat lenses. The as‐fabricated lenses exploit the tunable material property variations to effectively manipulate not only the amplitude but also the phase of the incident light to focus into a 3D focal spot with a sub‐wavelength resolution in the range of 0.5–0.9λ. The results pave the way toward low‐cost and large‐scale high‐resolution imaging applications in the future.
High‐Performance All‐Polymer Solar Cells Enabled by n‐Type Polymers with an Ultranarrow Bandgap Down to 1.28 eV
Authors: Feng Kui , Huang Jiachen , Zhang Xianhe , Wu Ziang , Shi Shengbin , Thomsen Lars , Tian Yanqing , Woo Han Young , McNeill Christopher R. , Guo Xugang 
Published: June 2020

AbstractCompared to organic solar cells based on narrow‐bandgap nonfullerene small‐molecule acceptors, the performance of all‐polymer solar cells (all‐PSCs) lags much behind due to the lack of high‐performance n‐type polymers, which should have low‐aligned frontier molecular orbital levels and narrow bandgap with broad and intense absorption extended to the near‐infrared region. Herein, two novel polymer acceptors, DCNBT‐TPC and DCNBT‐TPIC, are synthesized with ultranarrow bandgaps (ultra‐NBG) of 1.38 and 1.28 eV, respectively. When applied in transistors, both polymers show efficient charge transport with a highest electron mobility of 1.72 cm2 V−1 s−1 obtained for DCNBT‐TPC. Blended with a polymer donor, PBDTTT‐E‐T, the resultant all‐PSCs based on DCNBT‐TPC and DCNBT‐TPIC achieve remarkable power conversion efficiencies (PCEs) of 9.26% and 10.22% with short‐circuit currents up to 19.44 and 22.52 mA cm−2, respectively. This is the first example that a PCE of over 10% can be achieved using ultra‐NBG polymer acceptors with a photoresponse reaching 950 nm in all‐PSCs. These results demonstrate that ultra‐NBG polymer acceptors, in line with nonfullerene small‐molecule acceptors, are also available as a highly promising class of electron acceptors for maximizing device performance in all‐PSCs.
Photonic Multishells Composed of Cholesteric Liquid Crystals Designed by Controlled Phase Separation in Emulsion Drops
Authors: Park Sihun , Lee Sang Seok , Kim Shin‐Hyun 
Published: June 2020

AbstractCholesteric liquid crystals (CLCs), also known as chiral nematic LCs, show a photonic stopband, which is promising for various optical applications. In particular, CLCs confined in microcompartments are useful for sensing, lasing, and optical barcoding at the microscale. The integration of distinct CLCs into single microstructures can provide advanced functionality. In this work, CLC multishells with multiple stopbands are created by liquid–liquid phase separation (LLPS) in a simple yet highly controlled manner. A homogeneous ternary mixture of LC, hydrophilic liquid, and co‐solvent is microfluidically emulsified to form uniform oil‐in‐water drops, which undergo LLPS to form onion‐like drops composed of alternating CLC‐rich and CLC‐depleted layers. The multiplicity is controlled from one to five by adjusting the initial composition of the ternary mixture, which dictates the number of consecutive steps of LLPS. Interestingly, the concentration of the chiral dopant becomes reduced from the outermost to the innermost CLC drop due to uneven partitioning during LLPS, which results in multiple stopbands. Therefore, the photonic multishells show multiple structural colors. In addition, dye‐doped multishells provide band‐edge lasing at two different wavelengths. This new class of photonic multishells will provide new opportunities for advanced optical applications.
Toward Commercial Carbon Dioxide Electrolysis
Authors: Ganji Parameswaram , Borse Rahul Anil , Xie Jiafang , Mohamed Aya Gomaa Abdelkader , Wang Yaobing 
Published: June 2020

AbstractThe electrochemical carbon dioxide reduction reaction (ECDRR) driven by clean energy resources (such as wind, solar, etc.) to chemical feedstock and fuels is an attractive route to balance the carbon‐neutral cycle and for regenerating fuels. To date, the ECDRR has been the most promising technology for the conversion of carbon dioxide (CO2) to carbon‐building blocks, which has a huge market demand and increasing annual global production. Despite tremendous research, the conversion of CO2 into valuable fuels and chemicals is still challenging due to the highly inert and diverse CO2 reduction pathways towards high Faradaic efficiency, current density, and stability in the industrialization of ECDRR process. Herein, the most recent developments such as 1) the evaluation of the role of an electrocatalyst according to industrial production demands; 2) the performance of nanostructured electrocatalyst, electrolyte, and devices; 3) advantages and disadvantages of promising metals, such as Au, Ag, and Cu, and single‐atoms, such as Ni, Fe, and Co; and 4) the electrolyte effects, pH effects, and ion effects are described with a vision for ECDRR electrocatalysis towards industrialization. Finally, this review aims to offer forward‐looking, on‐going research/possible activities, together with future perspectives on the ECDRR process from a small‐scale production to industrialization.
Chlorination: An Effective Strategy for High‐Performance Organic Solar Cells
Authors: Zhao Qiaoqiao , Qu Jianfei , He Feng 
Published: June 2020

AbstractThis work summarizes recent developments in polymer solar cells (PSCs) prepared by a chlorination strategy. The intrinsic property of chlorine atoms, the progress of chlorinated polymers and small molecules, and the synergistic effect of chlorination with other methods to elevate solar conversions are discussed. Halogenation of donor–acceptor (D–A) materials is an effective method to improve the performance of PSCs, which mainly affects the push–pull of electrons between donor and acceptor units due to their strong electron‐withdrawing capabilities. Although chlorine is less electronegative than fluorine, it can form very strong noncovalent interactions, such as Cl···S and Cl···π interactions, because its empty 3d orbits can help to accept the electron pairs or π electrons. This synergistic effect of electronegativity together with the empty 3d orbits of chlorine atoms leads to increased intramolecular and intermolecular interactions and a much stronger capability to down‐shift the molecular energy levels. This work is intended to support a better understanding of the chlorination strategy to modify the material properties, and thus improve the performance of solar devices. Eventually, it will provide the research community with a clearer pathway to choose proper substitution methods according to different situations for high and stable solar energy conversion.
Organic Microbial Electrochemical Transistor Monitoring Extracellular Electron Transfer
Authors: Méhes Gábor , Roy Arghyamalya , Strakosas Xenofon , Berggren Magnus , Stavrinidou Eleni , Simon Daniel T. 
Published: June 2020

AbstractExtracellular electron transfer (EET) denotes the process of microbial respiration with electron transfer to extracellular acceptors and has been exploited in a range of microbial electrochemical systems (MESs). To further understand EET and to optimize the performance of MESs, a better understanding of the dynamics at the microscale is needed. However, the real‐time monitoring of EET at high spatiotemporal resolution would require sophisticated signal amplification. To amplify local EET signals, a miniaturized bioelectronic device, the so‐called organic microbial electrochemical transistor (OMECT), is developed, which includes Shewanella oneidensis MR‐1 integrated onto organic electrochemical transistors comprising poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) combined with poly(vinyl alcohol) (PVA). Bacteria are attached to the gate of the transistor by a chronoamperometric method and the successful attachment is confirmed by fluorescence microscopy. Monitoring EET with the OMECT configuration is achieved due to the inherent amplification of the transistor, revealing fast time‐responses to lactate. The limits of detection when using microfabricated gates as charge collectors are also investigated. The work is a first step toward understanding and monitoring EET in highly confined spaces via microfabricated organic electronic devices, and it can be of importance to study exoelectrogens in microenvironments, such as those of the human microbiome.
Skin‐Like Hybrid Integrated Circuits Conformal to Face for Continuous Respiratory Monitoring
Authors: Chen Ying , Liu Fei , Lu Bingwei , Zhang Yingchao , Feng Xue 
Published: June 2020

AbstractTo perform wearable and continuous health monitoring, epidermal electronics for all kinds of sensing have been developed, yet neither organic nor inorganic materials‐based epidermal devices are able to perform the functions like signal collection, processing, transmission, or power supply. Here, a strategy is reported to build skin‐like hybrid integrated circuits (SHICs) with stretchable sensors and commercial chips for long‐term respiratory monitoring. It can independently perform signal acquisition, processing, converting, and wireless transmission with carrying power supply. Thermal theory model is established to characterize the breathing air's interaction with the sensor, which helps in signal analysis. Respiratory monitoring on human body is tested in diverse daily activities including exercising, dining, drinking, and sleeping with a custom‐developed phone application to record and display the respiratory signal. Results show that the SHIC is of high efficiency and accuracy to track the breath patterns continuously in both static and moving scenarios. Furthermore, the SHIC is a feasible and promising platform that can be extended with multiple sensors or actuators in individualized medical applications and physiological study.
Operational Stability Enhancement of Polymeric Organic Field‐Effect Transistors by Amorphous Perfluoropolymers Chemically Anchored to Gate Dielectric Surfaces
Authors: Bulgarevich Kirill , Sakamoto Kenji , Yasuda Takeshi , Minari Takeo , Takeuchi Masayuki 
Published: June 2020

AbstractBias‐stress resistance of polymer‐based organic field‐effect transistors (OFETs) is considerably enhanced by coating the gate dielectric surface with an amorphous perfluoropolymer (CYTOP). In bottom‐gate (BG) OFETs offering a relatively simple fabrication process, the CYTOP coating causes a serious problem; that is, thin film formation of organic semiconducting polymers generally fails due to the lyophobic properties of CYTOP. This problem is solved by patterning the CYTOP coating layer with suitable designs. Here, a simple photo‐patterning method is established using CYTOP terminated with amidosilyl functional groups. This method is composed of self‐limited thinning process of CYTOP coating layers, exposure to vacuum ultraviolet light through a photomask, and development. BG/top‐contact OFET arrays are fabricated using poly(2,5‐bis(3‐hexadecylthiophene‐2‐yl)thieno[3,2‐b]thiophene) as the semiconducting polymer. The initial electrical properties and bias‐stress resistance are compared with those of OFETs with octadecyltrichlorosilane (ODTS)‐treated gate dielectrics. The CYTOP‐ and ODTS‐OFETs show approximately the same initial electrical properties with very small device‐to‐device variation, while the CYTOP‐OFETs exhibit much higher intrinsic bias‐stress resistance. Therefore, the spin‐coating combined with the simple photo‐patterning method is a promising technique that can form polymeric organic semiconductor layers on CYTOP layers and produce BG OFETs exhibiting very high operational stability.
Theoretical and Experimental Investigations on the Aggregation‐Enhanced Emission from Dark State: Vibronic Coupling Effect
Authors: Yin Ping‐An , Wan Qing , Niu Yingli , Peng Qian , Wang Zhiming , Li Yuxuan , Qin Anjun , Shuai Zhigang , Tang Ben Zhong 
Published: June 2020

AbstractAggregation‐induced/‐enhanced emission (AIE/AEE) has aroused broad interest. The mechanism behind is understood as the aggregation restriction of the nonradiative decay from electronically excited state to the ground state, either through interconversion or through conical intersection, leaving the dipole‐allowed radiative decay channel relatively intact. Here, a report on an AEE phenomenon for 5,10‐diphenylphenazine (DPhPZ) compound is presented, for which the experiment shows to be AEE active but the lowest excited state has been long known to be “dark state,” namely with zero transition dipole with the ground state according to Kasha’s rule. The computational studies demonstrate that the optical emission stems from the “dark state” with emission intensity borrowed from higher‐lying “bright state” through Herzberg–Teller vibronic coupling, and the resultant spectra are in good agreement with the experiment in terms of both line shape and peak position. The vibronic‐coupling‐induced radiative decay and the restricted nonradiative decay synergistically bring about highly efficient luminescence of DPhPZ in the solid phase. The findings open a new avenue for the development of solid‐emissive luminophores.
Ferroelastic‐Domain‐Assisted Mechanical Switching of Ferroelectric Domains in Pb(Zr,Ti)O3 Thin Films
Authors: Yuan Guoliang , Huang Houbing , Li Chen , Liu Di , Cheng Zhihao , Wu Di 
Published: June 2020

AbstractA recent breakthrough in mechanical polarization switching provides a valuable handle to achieve nanoscale ferroelectric domain control. This flexoelectric switching is usually observed in ultrathin films (≈10 nm or less in thickness), where a large strain gradient is possible. However, from the point of view of device applications, it will be more attractive to achieve mechanical domain switching in thicker films. Here, it is experimentally demonstrated that by introducing ferroelastic a‐domains in PbZr0.1Ti0.9O3 films the potential barrier against 180° c‐domain switching can be greatly decreased, enabling mechanical ferroelectric domain switching in 50 nm thick films by applying a loading force from an atomic force microscope tip. Moreover, these a‐domains are stable in the c‐domain matrix without further mechanical stressing. This makes it possible to create nanoscale domain wall circuitry. These results shed light on the mechanism of domain switching in ferroelectric thin films and may facilitate the design of mechanically controlled novel ferroelectric devices.
Indoor Thin‐Film Photovoltaics: Progress and Challenges
Authors: Li Meng , Igbari Femi , Wang Zhao‐Kui , Liao Liang‐Sheng 
Published: June 2020

AbstractEnergy generation and consumption have always been an important component of social development. Interests in this field are beginning to shift to indoor photovoltaics (IPV) which can serve as power sources under low light conditions to meet the energy needs of rapidly growing fields, such as intelligence gathering and information processing which usually operate via the Internet‐of‐things (IoT). Since the power requirements for this purpose continue to decrease, IPV systems under low light may facilitate the realization of self‐powered high‐tech electronic devices connected through the IoT. This review discusses and compares the characteristics of different types of IPV devices such as those based on silicon, dye, III‐V semiconductors, organic compounds, and halide perovskites. Among them, specific attention is paid to perovskite photovoltaics which may potentially become a high performing IPV system due to the fascinating photophysics of the halide perovskite active layer. The limitations of such indoor application as they relate to the toxicity, stability, and electronic structure of halide perovskites are also discussed. Finally, strategies which could produce highly functional, nontoxic, and stable perovskite photovoltaics devices for indoor applications are proposed.
Estimating rates and patterns of diversification with incomplete sampling: a case study in the rosids
Authors: Sun Miao , Folk Ryan A. , Gitzendanner Matthew A. , Soltis Pamela S. , Chen Zhiduan , Soltis Douglas E. , Guralnick Robert P. 
Published: June 2020

PremiseRecent advances in generating large‐scale phylogenies enable broad‐scale estimation of species diversification. These now common approaches typically are characterized by (1) incomplete species coverage without explicit sampling methodologies and/or (2) sparse backbone representation, and usually rely on presumed phylogenetic placements to account for species without molecular data. We used empirical examples to examine the effects of incomplete sampling on diversification estimation and provide constructive suggestions to ecologists and evolutionary biologists based on those results.MethodsWe used a supermatrix for rosids and one well‐sampled subclade (Cucurbitaceae) as empirical case studies. We compared results using these large phylogenies with those based on a previously inferred, smaller supermatrix and on a synthetic tree resource with complete taxonomic coverage. Finally, we simulated random and representative taxon sampling and explored the impact of sampling on three commonly used methods, both parametric (RPANDA and BAMM) and semiparametric (DR).ResultsWe found that the impact of sampling on diversification estimates was idiosyncratic and often strong. Compared to full empirical sampling, representative and random sampling schemes either depressed or inflated speciation rates, depending on methods and sampling schemes. No method was entirely robust to poor sampling, but BAMM was least sensitive to moderate levels of missing taxa.ConclusionsWe suggest caution against uncritical modeling of missing taxa using taxonomic data for poorly sampled trees and in the use of summary backbone trees and other data sets with high representative bias, and we stress the importance of explicit sampling methodologies in macroevolutionary studies.
An Interface‐Bridged Organic–Inorganic Layer that Suppresses Dendrite Formation and Side Reactions for Ultra‐Long‐Life Aqueous Zinc Metal Anodes
Authors: Cui Yanhui , Zhao Qinghe , Wu Xiaojun , Chen Xin , Yang Jinlong , Wang Yuetao , Qin Runzhi , Ding Shouxiang , Song Yongli , Wu Junwei , Yang Kai , Wang Zijian , Mei Zongwei , Song Zhibo , Wu Hong , Jiang Zhongyi , Qian Guoyu , Yang Luyi , Pan Feng 
Published: June 2020

AbstractAqueous zinc (Zn) batteries (AZBs) are widely considered as a promising candidate for next‐generation energy storage owing to their excellent safety features. However, the application of a Zn anode is hindered by severe dendrite formation and side reactions. Herein, an interfacial bridged organic–inorganic hybrid protection layer (Nafion‐Zn‐X) is developed by complexing inorganic Zn‐X zeolite nanoparticles with Nafion, which shifts ion transport from channel transport in Nafion to a hopping mechanism in the organic–inorganic interface. This unique organic–inorganic structure is found to effectively suppress dendrite growth and side reactions of the Zn anode. Consequently, the Zn@Nafion‐Zn‐X composite anode delivers high coulombic efficiency (ca. 97 %), deep Zn plating/stripping (10 mAh cm−2), and long cycle life (over 10 000 cycles). By tackling the intrinsic chemical/electrochemical issues, the proposed strategy provides a versatile remedy for the limited cycle life of the Zn anode.
A Chiral Naphthyridine Diimine Ligand Enables Nickel‐Catalyzed Asymmetric Alkylidenecyclopropanations
Authors: Braconi Elena , Cramer Nicolai 
Published: June 2020

AbstractA novel class of chiral naphthyridine diimine ligands (NDI*) readily accessible from C2‐symmetric 2,6‐di‐(1‐arylethyl)anilines is described. The utility of these ligands, particularly one with fluorinated aryl side arms, is demonstrated by a reductive Ni‐catalyzed enantioselective alkylidene transfer reaction from 1,1‐dichloroalkenes to olefins. This transformation provides direct access to a broad range of synthetically valuable alkylidenecyclopropanes in high yields and enantioselectivities.
Dual‐Mode Superresolution Imaging Using Charge Transfer Dynamics in Semiconducting Polymer Dots
Authors: Jiang Yifei , Hu Qiongzheng , Chen Haobin , Zhang Jicheng , Chiu Daniel T. , McNeill Jason 
Published: June 2020

AbstractIn a conjugated polymer‐based single‐particle heterojunction, stochastic fluctuations of the photogenerated hole population lead to spontaneous fluorescence switching. We found that 405 nm irradiation can induce charge recombination and activate the single‐particle emission. Based on these phenomena, we developed a novel class of semiconducting polymer dots that can operate in two superresolution imaging modes. The spontaneous switching mode offers efficient imaging of large areas, with <10 nm localization precision, while the photoactivation/deactivation mode offers slower imaging, with further improved localization precision (ca. 1 nm), showing advantages in resolving small structures that require high spatial resolution. Superresolution imaging of microtubules and clathrin‐coated pits was demonstrated, under both modes. The excellent localization precision and versatile imaging options provided by these nanoparticles offer clear advantages for imaging of various biological systems.