bluuebunny/crossref_metadata_2025 huggingface dataset:
Tunable Conductive Hydrogel Scaffolds for Neural Cell Differentiation
Authors: Tringides Christina M. , Boulingre Marjolaine , Khalil Andrew , Lungjangwa Tenzin , Jaenisch Rudolf , Mooney David J.
Published: December 2022

Multielectrode arrays would benefit from intimate engagement with neural cells, but typical arrays do not present a physical environment that mimics that of neural tissues. It is hypothesized that a porous, conductive hydrogel scaffold with appropriate mechanical and conductive properties could support neural cells in 3D, while tunable electrical and mechanical properties could modulate the growth and differentiation of the cellular networks. By incorporating carbon nanomaterials into an alginate hydrogel matrix, and then freeze‐drying the formulations, scaffolds which mimic neural tissue properties are formed. Neural progenitor cells (NPCs) incorporated in the scaffolds form neurite networks which span the material in 3D and differentiate into astrocytes and myelinating oligodendrocytes. Viscoelastic and more conductive scaffolds produce more dense neurite networks, with an increased percentage of astrocytes and higher myelination. Application of exogenous electrical stimulation to the scaffolds increases the percentage of astrocytes and the supporting cells localize differently with the surrounding neurons. The tunable biomaterial scaffolds can support neural cocultures for over 12 weeks, and enable a physiologically mimicking in vitro platform to study the formation of neuronal networks. As these materials have sufficient electrical properties to be used as electrodes in implantable arrays, they may allow for the creation of biohybrid neural interfaces and living electrodes.
Correlation between Fibrin Fibrillation Kinetics and the Resulting Fibrin Network Microstructure
Authors: Pietsch Katja , Storm‐Johannsen Lisa , Schmidt‐Thomée Antonia , Pompe Tilo
Published: December 2022

Fibrin, the prominent extracellular matrix in early wound tissue, is discussed to influence immune cells and healing. The nature of fibrinogen/fibrin to form fibrillary networks is frequently exploited to engineer microenvironments for cellular analysis. This study focuses on revealing the correlation of fibril formation kinetic and the resulting network microstructure of engineered 3D fibrin networks. Different concentrations of fibrinogen (1–3 mg mL−1), thrombin (0.01–0.15 U mL−1), sodium chloride (40–120 mm), and calcium chloride (1–10 mm) are applied to assess the impact on the fibril growth kinetics by turbidity analysis and on the resulting fibril and pore diameter by laser scanning microscopy. The results highlight a direct influence of the sodium chloride concentration on fibrillation kinetics and reveal a strong correlation between fibrillation kinetics and network microstructure. With the assumption of a first‐order growth kinetic, an increase of the growth constant k (0.015–0.04 min−1) is found to correlate to a decrease in fibril diameter (1–0.65 µm) and pore diameter (11–5 µm). The new findings enable an easy prediction of 3D fibrin network microstructure by the fibril formation kinetic and contribute to an improved engineering of defined scaffolds for tissue engineering and cell culture applications.
A Photoacoustic Contrast Nanoagent with a Distinct Spectral Signature for Ovarian Cancer Management
Authors: St Lorenz Anna , Moses Abraham S. , Mamnoon Babak , Demessie Ananiya A. , Park Youngrong , Singh Prem , Taratula Oleh , Taratula Olena R.
Published: December 2022

Photoacoustic imaging (PAI) has tremendous potential for improving ovarian cancer detection. However, the lack of effective exogenous contrast agents that can improve PAI diagnosis accuracy significantly limits this application. This study presents a novel contrast nanoagent with a specific spectral signature that can be easily distinguished from endogenous chromophores in cancer tissue, allowing for high‐contrast tumor visualization. Constructed as a 40 nm biocompatible polymeric nanoparticle loaded with two naphthalocyanine dyes, this agent is capable of efficient ovarian tumor accumulation after intravenous injection. The developed nanoagent displays a spectral signature with two well‐separated photoacoustic peaks of comparable PA intensities in the near‐infrared (NIR) region at 770 and 860 nm, which remain unaffected in cancer tissue following systemic delivery. In vivo experiments in mice with subcutaneous and intraperitoneal ovarian cancer xenografts validate that this specific spectral signature allows for accurate spectral unmixing of the nanoagent signal from endogenous contrast in cancer tissue, allowing for sensitive noninvasive cancer diagnosis. In addition, this nanoagent can selectively eradicate ovarian cancer tissue with a single dose of photothermal therapy by elevating the intratumoral temperature to ≈49 °C upon exposure to NIR light within the 700–900 nm range.
Closed‐Loop Recyclable High‐Performance Polyimine Aerogels Derived from Bio‐Based Resources
Authors: Wang Changlin , Eisenreich Fabian , Tomović Željko
Published: December 2022

Organic aerogels are an intriguing class of highly porous and ultralight materials which have found widespread applications in thermal insulation, energy storage, and chemical absorption. These fully cross‐linked polymeric networks, however, pose environmental concerns as they are typically made from fossil‐based feedstock and the recycling back to their original monomers is virtually impossible. In addition, organic aerogels suffer from low thermal stability and potential fire hazard. To overcome these obstacles and create next‐generation organic aerogels, a set of polyimine aerogels containing reversible chemical bonds which can selectively be cleaved on demand is prepared. As precursors, different primary amines and cyclophosphazene derivatives made from bio‐based reagents (vanillin and 4‐hydroxybenzaldehyde) to elevate the thermal stability and reduce the environmental impact are used. The resulting polyimine aerogels exhibit low shrinkage, high porosity, large surface area, as well as pronounced thermal stability and flame resistance. More importantly, the aerogels show excellent recyclability under acidic conditions with high monomer recovery yields and purities. This approach allows for preparation of fresh aerogels from the retrieved building blocks, thus demonstrating efficient closed‐loop recycling. These high‐performance, recyclable, and bio‐based polyimine aerogels pave the way for advanced and sustainable superinsulating materials.
Bidirectional Water‐Stream Behavior on a Multifunctional Membrane for Simultaneous Energy Generation and Water Purification
Authors: Jang Ji‐Soo , Lim Yunsung , Shin Hamin , Kim Jihan , Yun Tae Gwang
Published: December 2022

Hydroelectric nanogenerators have been previously proposed to recycle various water resources and polluted water. However, as conventional hydroelectric nanogenerators only utilize water resources, they cannot provide a fundamental solution for water recycling. In this study, a water purification membrane is proposed that can simultaneously generate electricity during the purification process (electricity generation and purification membrane (EPM)) for water recycling. As polluted water passes through the EPM, the water is purified in the perpendicular direction, while electricity is simultaneously produced in the horizontal direction by the movement of ions. Notably, the EPM exhibits high energy generation performance (maximum power 16.44 µW and energy 15.16 mJ) by the streaming effect of water‐streaming carbon nanotubes (CNTs). Moreover, by using a poly(acrylic acid)/carboxymethyl cellulose (PAA/CMC) binder to EPM, the energy‐generation performance and long‐term stability are substantially improved and outstanding mechanical stability is provided, regardless of the acidity of the water source (pH 1–10). More importantly, the EPM exhibits the water purification characteristics of >90% rejection of sub‐10 nm pollutants and potentiality of ångstrom level cation rejection, with simultaneous and continuous energy generation. Overall, this study proposes an efficient EPM model, which can be potentially used as a next‐generation renewable energy generation approach, thus laying the foundation for effective utilization of polluted water resources.
Current Understanding of the Wettability of MXenes
Authors: Yu LePing , Lu Lu , Zhou XiaoHong , Xu Lyu
Published: December 2022

Since the first report regarding the successful fabrication of few‐layer transition metal carbides (known as MXenes) of 2011, their intrinsic properties, such as mechanical strength and electrical conductivity, are intensively studied. Though the hydrophilic nature of MXenes is widely reported and utilized to fabricate various functional materials, there is a lack of systematic study with respect to the science behind the wetting phenomena of MXene‐based materials. The goal of this manuscript is to provide some useful guidelines in the design of novel MXene‐based systems with desirable wetting properties by analyzing the current understanding of the wettability of MXenes. Specifically, after the introduction of the fundamental concepts in wetting theory, the wettability of pure MXene films is summarized based on the recently published results from both theoretical and experimental studies. Then, the determining factors in the wetting properties of MXenes associated with surface architectures and chemical compositions are clarified, which is followed by the effect of hybridization strategies discussed in detail. In the end, a summary of the abundant applications relying on the wetting properties of MXene‐based systems is presented along with the current challenges and the corresponding future research directions in this field.
Resolving Oxidation States and X–site Composition of Sn Perovskites through Auger Parameter Analysis in XPS
Authors: Wieczorek Alexander , Lai Huagui , Pious Johnpaul , Fu Fan , Siol Sebastian
Published: December 2022

Reliable chemical state analysis of Sn semiconductors by XPS is hindered by the marginal observed binding energy shift in the Sn 3d region. For hybrid Sn‐based perovskites especially, errors associated with charge referencing can easily exceed chemistry‐related shifts. Studies based on the modified Auger parameter α ′ provide a suitable alternative and have been used previously to resolve different chemical states in Sn alloys and oxides. However, the meaningful interpretation of Auger parameter variations on Sn‐based perovskite semiconductors requires fundamental studies. In this work, a comprehensive Auger parameter study is performed through systematic compositional variations of Sn halide perovskites. It is found that in addition to the oxidation state, α ′ is highly sensitive to the composition of the halide site, inducing shifts of up to Δα ′ = 2 eV between ASnI3 and ASnBr3 type perovskites. The reported dependencies of α ′ on the Sn oxidation state, coordination and local chemistry provide a framework that enables reliable tracking of degradation as well as X‐site composition for Sn‐based perovskites and related compounds. The higher robustness and sensitivity of such studies not only enables more in‐depth surface analysis of Sn‐based perovskites than previously performed, but also increases reproducibility across laboratories.
Biomimetic Superhydrophobic Materials Construct from Binary Structure: A Review on Design, Properties, and Applications
Authors: Li Jiahao , Guo Zhiguang , Liu Weimin
Published: December 2022

In recent decades, the development of biomimetic superhydrophobic surface structures has allowed several properties of superhydrophobic materials to be increasingly developed. This review addresses mainly three aspects. First, two kinds of structures with superhydrophobic properties: binary structures and unitary structures, are analyzed and compared. The binary structure, which includes micro‐ and nanostructures, is responsible for the development of superhydrophobicity in most natural creatures and artificial materials. And hierarchical binary structures, which combine micro‐ and nanoscale structures, actually perform better at superhydrophobic. Second, various properties of superhydrophobic materials achieved through binary structures, including self‐cleaning, antireflection, drag‐reduction, and mechanically robust and durable superhydrophobic surfaces are summarized. Each structure possesses both superiority and vulnerability. The combination of various structures can help develop adaptable and practical materials. Finally, the combinations of different properties in superhydrophobic via using a binary structure are enumerated. Materials with various properties can adapt to different working environments.
Blue Light Hazard Optimization for White Light‐Emitting Diode of Mn2+‐Activated 0D Cs3Cu2Br5 Perovskite Materials
Authors: Liu Yaoyu , Zheng Xixi , Ji Zongshuai , Wang Tianyu , Yu Haixia , Teng Bing , Ji Shaohua
Published: December 2022

The zero‐dimensional perovskite‐like derivative Cs3Cu2X5 (X = Cl, Br, I) with self‐trapped excitons (STEs) photoluminescence (PL) has attracted tremendous interest in the field of optoelectronics. Nonetheless, it is challenging for Cs3Cu2Br5 material to attain full visible spectrum emission and prevent light‐induced photochemical damage to the retina (blue light hazard) in applications. Herein, Mn2+ is chosen as the dopant to alloy into Cs3Cu2X5 via a one‐step solid state synthesis method. Significantly, the series of Mn2+‐doped show the emission peak of 460 nm STEs and the emission peak of 550 nm Mn2+. More importantly, the high energy absorption of Mn2+ facilitates the transfer of exciton energy, contributing to a reduction in blue emission peak at 460 nm. Simultaneously, ≈17.5% of Mn2+ is alloyed into the Cs3Cu2X5lattice to induce the energy transfer channels from the Cs3Cu2X5 host to the Mn2+ guest to lead to the emission of Mn2+, which broadens emission spectrum (400–620 nm) and realizes 80% reduction of the blue emission peak at 460 nm. Additionally, a white light‐emitting diodes can decrease the blue emission band via 71.45% and an ultrahigh color rendering index (CRI) of 94.5 is produced using the 17.5% Mn2+: Cs3Cu2X5 perovskite‐like derivative powder material.
Reduction Mechanism for CeO2 Revealed by Direct Observation of the Oxygen Vacancy Distribution in Shape‐Controlled CeO2
Authors: Hojo Hajime , Hirota Kazuki , Ito So , Einaga Hisahiro
Published: December 2022

CeO2 and CeO2‐based materials are widely used as catalysts and catalyst supports for a variety of chemical reactions. The ability to form oxygen vacancies plays an important role in the catalytic activities in these materials. Therefore, revealing the reduction mechanism for CeO2 is crucial to understanding the catalytic activities. In this study, shape‐controlled CeO2 nanoparticles are fabricated and the distribution of surface oxygen vacancies on the (100) and (111) surfaces is systematically studied using scanning transmission electron microscopy and electron energy‐loss spectroscopy and the response to H2 reduction treatment. It is successfully demonstrated that both catalytic activities and the ability to form oxygen vacancies are strongly dependent on the type of lattice planes. Moreover, the present results provide important insights into the reduction mechanism for CeO2, in which bulk oxygen instead of the widely believed surface capping oxygen makes no small contribution to the initial reduction step.
Silver Nanoparticle‐Decorated Reduced Graphene Oxide Nanomaterials Exert Membrane Stress and Induce Immune Response to Inhibit the Early Phase of HIV‐1 Infection
Authors: Mukherjee Soumajit , Bytesnikova Zuzana , Martin Sophie , Svec Pavel , Ridoskova Andrea , Pekarkova Jana , Seguin Cendrine , Weickert Jean‐Luc , Messaddeq Nadia , Mély Yves , Richtera Lukas , Anton Halina , Adam Vojtech
Published: December 2022

Graphene‐based 2D nanomaterials exhibit unique physicochemical, electric, and optical properties that facilitate applications in a wide range of fields including material science, electronics, and biotechnology. Recent studies have shown that graphene oxide (GO) and reduced graphene oxide (rGO) exhibit antimicrobial effects on bacteria and viruses. While the bactericidal activity of graphene‐based nanomaterials is related to mechanical and oxidative damage to bacterial membranes, their antiviral activity has been less explored. Currently available experimental data are limited and suggest mechanical disruption of viral particles prior to infection. In this study, the antiviral properties of reduced GO‐based nanocomposites decorated with Ag nanoparticles (rGO‐Ag) are evidenced against human immunodeficiency virus‐1 pseudovirus used as an enveloped virus model. By combining biochemical and original single virus imaging approaches, it is shown that rGO‐Ag induces peroxidation of pseudoviral lipid membrane and that consequent alteration of membrane properties leads to a reduction in cell entry. In addition, rGO‐Ag is found to be efficiently internalized in the host cell leading to the elevated expression of pro‐inflammatory cytokines. Altogether, the presented results shed new light on the mechanisms of rGO‐Ag antiviral properties and confirm the high potential of graphene derivatives as an antimicrobial material for biomedical applications.
Nitrogenous Interlayers for ITO S/D Electrodes in N‐Type Organic Thin Film Transistors
Authors: Rong Xin , Han Jiangli , Xu Chenhui , Ma Botai , Jiang Lixian , Ma Ding , Xing Rubo , Shen Liping , Duan Lian , Deng Yunfeng , Geng Yanhou , Dong Guifang
Published: December 2022

The commercialization of organic thin film transistors (OTFTs) is partly hindered by the high cost and stubborn work function (WF) of common Au source/drain (S/D) electrodes. In this work, indium tin oxide (ITO) S/D electrodes modified with three different nitrogenous interlayers including 1,4‐bis(2‐hydroxyethyl) piperazine (HEP), polyethylenimine ethoxylated (PEIE), and branched polyethylenimine (PEI) are adopted to fabricate n‐type OTFTs. The WF of bare ITO is 4.7 eV, whereas ITO modified with nitrogenous interlayers exhibits WFs ranging from 4.1 to 3.6 eV. By the first‐principle calculation and element analysis, the protonated amines are critical for the reduction of ITO surface WF. Besides, the interlayers with higher nitrogen contents are more likely to improve the wettability of octadecyltrichlorosilane (OTS) modified ITO substrates, and help to gain the continuous and oriented poly[2,5‐bis(4‐tetradecyloctadecyl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione‐alt‐5,5′‐di(thiophen‐2‐yl)‐2,2′‐(E)‐1,2‐bis(3,4‐difluorothien‐2‐yl)‐ethene] (P4FTVT‐C32) semiconductor thin films. Therefore, P4FTVT‐C32 based OTFTs with maximum electron field‐effect mobility of 1.95 cm2 V−1 s−1 are achieved by PEI treatments. These results indicate that the ITO S/D electrodes modified by nitrogenous interlayers can greatly slash costs and promote commercialization of OTFTs.
C1N1 Thin Films from Guanine Decomposition Fragments
Authors: Jerigová Mária , Heske Julian , Kühne ThomasD. , Tian Zhihong , Tovar Michael , Odziomek Mateusz , López‐Salas Nieves
Published: December 2022

Polymeric semiconductors are finding a wide range of applications. In particular, graphitic carbon nitride g‐C3N4 has been investigated extensively in the past decade. However, the family of carbon nitrides is not limited to C3N4 and new CXNY are now being explored due to their different bandgap energy, morphology, and overall physicochemical properties. Here, homogenous and semi‐transparent C1N1 thin films are fabricated using guanine as a nontoxic molecular precursor. They are synthesized in a simplified chemical vapor deposition process on top of fused silica and fluorine doped tin oxide coated glass substrates. The chemical and structural studies reveal that C/N ratio is close to target 1, triazine vibrations are visible in vibrational spectra and stacking of the film is observed from glancing incidence X‐ray diffraction data. The (photo)electrochemical properties are studied, the film is a p‐type semiconductor with a good photoresponse to visible light and a suitable catalyst for hydrogen evolution reaction. A simple and safe way of synthesizing C1N1 films on a range of substrates is presented here.
Economical Silicon Nanowire Growth via Cooling Controlled Solid–Liquid–Solid Mechanism
Authors: Nguyen Thao , Hsu Chu‐Hsiu , Lien Der‐Hsien , Su Yu‐Sheng
Published: December 2022

Conventional vapor–liquid–solid mechanism of nanowire growth opens up new opportunities of fabricating nanowires with controllable morphologies and aspect ratios. However, gaseous precursors have disadvantages of high material and processing cost, high toxicity, and limited scalability. By contrast, synthesizing nanowires via solid–liquid–solid mechanism could be a facile alternative since the low cost and nontoxic solid precursor is adopted in the process. In this study, the cooling control is found to be very critical for the solid–liquid–solid nanowire growth. Without a sufficient negative vertical temperature gradient, the nucleation and continuous growth of silicon nanowires could not occur. High volume gas flow cooling, fluctuating the heating temperature, decreasing the cooling rate, and applying a heat sink are all efficacious to promote silicon nanowire formation. In addition to the nanowires formed under high gas flow cooling on the silicon wafer sputtered with a nickel thin film, the solid–liquid–solid mechanism‐derived silicon nanowire growth can also be economically achieved by adopting a solution‐based coating of a nickel precursor onto the silicon substrate paired with a programmed slow cooling condition without using any gas, which could be transferred to other eutectic systems for cost‐effective nanomaterial fabrication.
How Thin and Efficient Can a Metasurface Reflector Be? Universal Bounds on Reflection for Any Direction and Polarization
Authors: Abdelrahman Mohamed Ismail , Monticone Francesco
Published: December 2022

Light reflection plays a crucial role in a number of modern technologies. In this paper, analytical expressions for maximal reflected power in any direction and for any polarization are given for generic planar structures made of a single material represented by a complex scalar susceptibility. The problem of optimal light‐matter interactions to maximize reflection is formulated as the solution of an optimization problem in terms of the induced currents, subject to energy conservation and passivity, which admits a global upper bound by using Lagrangian duality. The derived upper bounds apply to a broad range of planar structures, including metasurfaces, gratings, homogenized films, photonic crystal slabs, and more generally, any inhomogeneous planar structure irrespective of its geometrical details. These bounds also set the limit on the minimum possible thickness, for a given lossy material, to achieve a desired reflectance. Moreover, the results allow the discovery of parameter regions where large improvements in the efficiency of a reflective structure are possible compared to existing designs. Examples are given of the implications of these findings for the design of superior and compact reflective components made of real, imperfect (i.e., lossy) materials, such as ultra‐thin and efficient gratings, polarization converters, and light‐weight mirrors for solar/laser sails.
Circularly Polarized Luminescence from Atomically Precise Gold Nanoclusters Helically Assembled by Liquid‐Crystal Template
Authors: Lipok Maciej , Obstarczyk Patryk , Parzyszek Sylwia , Wang Yanan , Bagiński Maciej , Buergi Thomas , Lewandowski Wiktor , Olesiak‐Bańska Joanna
Published: December 2022

Chiral plasmonic gold nanoparticles assemblies are known for their strong circular dichroism. However, little is known about the creation of helical assemblies from atomically precise nanoparticles like gold nanoclusters (AuNCs) and the optical properties of the final structures. Herein, a new approach is proposed to helically assemble atomically precise gold nanoclusters and enable circularly polarized luminescence using a liquid‐crystal template creating helical nanofilaments. The problem of nanoclusters miscibility is resolved with the liquid crystal matrix by functionalizing nanoclusters with two different ligands: dodecanethiol and specially designed liquid crystal‐like ligand. Additionally, the authors explore how functionalization, heating, and helical assembly affect optical properties of gold nanoclusters. The findings prove that assembly incorporating thermotropic liquid crystals and double functionalization of nanocluster surface can be successfully applied to assemble ultrasmall nanoparticles in a helical manner while preserving their atomically precise structure. Moreover, the assembly tunes the nanocluster luminescence and generates new chiroptical effects.
Unraveling Dipolar Regime and Kerker Conditions in Mid‐Index Mesoscale Dielectric Materials
Authors: Coe Brighton , Olmos‐Trigo Jorge , Qualls Dylan , Alexis Minani , Szczerba Michal , Abujetas Diego R. , Biswas Mahua , Manna Uttam
Published: December 2022

Nanophotonic phenomena, such as zero optical back scattering, nonradiating anapole states, etc. are related to the excitation of single dipolar modes—hence so far, they have only been observed within a few relatively high‐index dielectric materials (refractive index, n > 3.5) in the nanoscale regime at the optical frequencies. Here, dipolar regime is unraveled, close‐to‐zero backscattering is demonstrated, and optical anapoles are excited in mid‐index dielectric spheres (titanium di‐oxide, TiO2; n ≈ 2.6) at the mesoscale regime (particle diameter, d ≈ incident wavelength, λ) under illumination with tightly focused Gaussian beams (TFGBs). Successive scattering minima associated with dipolar excitation are observed satisfying the first Kerker condition in the scattering spectra of single TiO2 spheres with diameters in the micrometer range. Moreover, at specific wavelengths, the electric and magnetic dipolar scattering amplitudes of the dielectric microspheres simultaneously go close‐to‐zero, leading to the excitation of hybrid optical anapoles with a total scattering intensity ≈ 5 times weaker for TFGB illumination with numerical aperture, NA ≈ 0.95 compared to NA ≈ 0.1. The result pushes the boundary of the observation of nanophotonic phenomena to a new regime with regards to type and size of the materials.
Enhanced Exciton‐to‐Mn2+ Energy Transfer in 3D/0D Cesium–Lead–Chloride Composite Perovskites
Authors: Zhong Chu‐Yao , Li Ladi , Chen Qing , Jiang Kai‐Zhe , Li Fa‐tang , Liu Zhao‐Qing , Chen Yibo
Published: December 2022

Doping cesium lead halide perovskite nanocrystals (NCs) with Mn2+ brings attractive long‐wavelength emission and flexible color tunability. However, due to multiple competing factors, the exciton‐to‐Mn2+ energy transfer efficiency is low. In this work, a simple structure‐optimization strategy is applied to enhance the exciton‐to‐Mn2+ energy transfer by synthesizing Mn2+ activated 3D/0D Cs–Pb–Cl perovskite composition composed of 3D CsPbCl3 and 0D Cs4PbCl6 NCs. The results reveal that the energy transfer efficiency and the photoluminescence quantum efficiency of the Cs–Pb–Cl composite are 65.3% and 77.3%, respectively, which are 1.4 and 3 times the corresponding values of the single‐phase CsPbCl3:Mn2+ NCs. Based on the detailed experimental and calculation results, the performance enhancement is demonstrated to stem from the optimized growth process of 3D CsPbCl3 NCs when co‐generating with 0D Cs4PbCl6 NCs. The strong lattice rigidity of the optimized CsPbCl3 NCs suppresses the nonradiative combination rate of the excitons, thus alleviating the main competing factor of the energy transfer process and improving the energy transfer efficiency. Fabrication of a white light‐emitting diode prototype further illustrates the application potential of the orange‐emitting Cs–Pb–Cl composite NCs for general lighting.
Manipulation of Longitudinally Inhomogeneous Polarization States Empowered by All‐Silicon Metasurfaces
Authors: Li Hui , Duan Shouxin , Zheng Chenglong , Li Jie , Xu Hang , Song Chunyu , Li Jitao , Yang Fan , Shi Wei , Zhang Yating , Shen Yun , Yao Jianquan
Published: December 2022

Polarization plays a key role in fundamental science, and manipulating the evolutionary trends of longitudinal polarization states can provide new implements for light–matter interaction. However, existing 3D optical devices can only manipulate the polarization conversion in a single transverse plane. Recently, methods to control polarization by cascading bulky optical systems are miniaturized using metasurfaces. Nevertheless, it is quite challenging to generate focused beams with vectorial properties for metasurfaces carrying inhomogeneous polarization profiles. Here, a single‐layer all‐silicon metasurface operating in the terahertz (THz) band is demonstrated to address all those aforementioned challenges in one go, and pencil‐like beams with inhomogeneous polarization profiles can be imparted along the propagation direction. The introduction of a latitudinal polarization control factor representing the initial phase difference enables near‐even manipulation of the evolutionary trend of the longitudinal polarization state according to the extended focal depth. By manipulating the topological charges within two orthogonal circularly polarized channels to accomplish coherent superposition, a focused vortex beam with vectorial properties can be generated in desired planes. Two functional demonstrations based on this approach are established experimentally, offering promising opportunities for structured light on meta‐optics.
Highly Nonlinear Multimode Tellurite Fibers: From Glass Synthesis to Practical Applications in Multiphoton Imaging
Authors: Evrard Marianne , Mansuryan Tigran , Couderc Vincent , Désévédavy Frédéric , Strutynski Clément , Dussauze Marc , Arosa Lobato Yago , Tonello Alessandro , Colas Maggy , El-Dib Georges , Danto Sylvain , Cardinal Thierry , Smektala Frédéric
Published: December 2022

Herein, a tellurite multimode optical fiber with a rectangular step‐index core to combine easy coupling of the pump power with the exceptionally cubic nonlinearity of such type of glass is developed. An alkali‐free composition (TeO2–ZnO–La2O3) is prepared to produce a preform with the use of both the stack‐and‐draw and the direct‐bonding methods. The linear and nonlinear optical responses of the fiber are characterized and are then used to generate a homogeneous supercontinuum (SC) in the near‐infrared domain. The spectral broadening, which is obtained in this work in a short fiber sample, is used for imaging mouse kidney cells, labeled with three different fluorochromes, by means of two‐photon absorption (2PA) and three‐photon absorption (3PA). Despite the multimode nature of the output beam, clear images of tubules, actin, and nucleus are collected with a spatial resolution down to 1.2 μm. Although image acquisition at better resolution has already been reported in the literature using relatively long spans of graded‐index silica multimode fibers, here, the combination of high third‐order susceptibility of the glass and the large Raman gain in short segments of tellurite fiber is exploited to obtain nonlinear imaging with adequate spatial resolution.
Upconverting Near‐Infrared Light Detection in Lead Halide Perovskite with Core–Shell Lanthanide Nanoparticles
Authors: Ishii Ayumi , Miyasaka Tsutomu
Published: December 2022

Light detection in the near‐infrared (NIR) region is necessary in a wide range of optical applications, such as optical communication, medical diagnostics, and environmental analysis. Herein, a novel NIR detection method based on energy conversion by upconversion (UC) materials is demonstrated. Nanoparticles (NPs) containing erbium (Er) ions are used as the UC material. Conventional NPs that contain ≈2 mol% Er ions have very weak light absorption ability, which is dramatically improved by incorporating high concentrations of Er ions (≈100 mol%). By coating the NP surfaces with inorganic perovskite containing heavy atoms (CsPbBr3) instead of organic alkyl chains, the thermal vibrations that deactivate the UC emission are suppressed effectively, resulting in high UC emission quantum efficiency of >5%. The perovskite coating process facilitates the introduction of the NPs into CsPbI3 thin films (which absorbs visible light only) and forms highly crystalline and uniform thin films. The resulting CsPbI3 thin film can be excited with NIR light, showing the emission from CsPbI3 via the UC. This enables fabrication of a UC‐based photodetector generating a photocurrent signal through the energy conversion process from NIR to visible light. The photodetector shows a high responsivity to weak NIR light with the quantum conversion efficiency of 75%.
Combining a Density Gradient of Biomacromolecular Nanoparticles with Biological Effectors in an Electrospun Fiber‐Based Nerve Guidance Conduit to Promote Peripheral Nerve Repair
Authors: Jin Binghui , Yu Yiling , Lou Chenghao , Zhang Xiaodi , Gong Bowen , Chen Jinghao , Chen Xiangxiang , Zhou Zihan , Zhang Liqun , Xiao Jian , Xue Jiajia
Published: December 2022

Peripheral nerve injury is a serious medical problem with limited surgical and clinical treatment options. It is of great significance to integrate multiple guidance cues in one platform of nerve guidance conduits (NGCs) to promote axonal elongation and functional recovery. Here, a multi‐functional NGC is constructed to promote nerve regeneration by combining ordered topological structure, density gradient of biomacromolecular nanoparticles, and controlled delivery of biological effectors to provide the topographical, haptotactic, and biological cues, respectively. On the surface of aligned polycaprolactone nanofibers, a density gradient of bioactive nanoparticles capable of delivering recombinant human acidic fibroblast growth factor is deposited. On the graded scaffold, the proliferation of Schwann cells is promoted, and the directional extension of neurites from both PC12 cells and dorsal root ganglions is improved in the direction of increasing particle density. After being implanted in vivo for 6 and 12 weeks to repair a 10‐mm rat sciatic nerve defect, the NGC promotes axonal elongation and remyelination, achieving the regeneration of the nerve not only in anatomical structure but also in functional recovery. Taken together, the NGC provides a favorable microenvironment for peripheral nerve regeneration and holds great promise for realizing nerve repair with an efficacy close to autograft.
Scar‐Degrading Endothelial Cells as a Treatment for Advanced Liver Fibrosis
Authors: Zhao Peng , Sun Tian , Lyu Cheng , Liang Kaini , Niu Yudi , Zhang Yuying , Cao Chenhui , Xiang Canhong , Du Yanan
Published: December 2022

Deposition of extracellular matrix (ECM) in the liver is an important feature of liver cirrhosis. Recovery from liver cirrhosis is physiologically challenging, partially due to the ECM in scar tissue showing resistance to cell‐mediated degradation by secreted matrix metalloproteinases (MMPs). Here, a cell‐mediated ECM‐degradation screening system (CEDSS) in vitro is constructed for high‐throughput searching for cells with tremendous degradation ability. ECM‐degrading liver sinusoidal endothelial cells (dLSECs) are screened using CEDSS, which exhibit 17 times the ability to degrade collagen when compared to other cells. The degradation ability of dLSECs is mediated by the upregulation of MMP9. In particular, mRNA expression of MMP9 shows an 833‐fold increase in dLSECs compared to normal endothelial cells (nLSECs), and MMP9 is regulated by transcription factor c‐Fos. In vivo, single intrasplenic injection of dLSECs alleviates advanced liver fibrosis in mice, while intraperitoneal administration of liver‐targeting peptide‐modified dLSECs shows enhanced fibrosis‐targeting effects. Degradative human umbilical vein endothelial cells (dHUVECs) prove their enhanced potential of clinical translation. Together, these results highlight the potential of ECM‐degrading endothelial cells in alleviating advanced liver fibrosis, thus providing remarkable insights in the development of ECM‐targeting therapeutics.
Peptide Supramolecular Assembly‐Instructed In Situ Self‐Aggregation for Stratified Targeting Sonodynamic Therapy Enhancement of AIE Luminogens
Authors: Jiang Weixi , Cheng Chen , Qiu Xiaoling , Chen Li , Guo Xun , Luo Yuanli , Wang Jingxue , Wang Junrui , Xie Zhuoyan , Li Pan , Wang Zhigang , Ran Haitao , Zhou Zhiyi , Ren Jianli
Published: December 2022

The emergence of aggregation‐induced emission luminogens (AIEgens) has attracted substantial scientific attention. However, their antitumor efficacy in photodynamic therapy (PDT) is significantly restricted by the poor water solubility and limited treatment depth. Therefore, a novel AIEgens‐involved therapeutic platform with good permeability and bioavailability is urgently required. Herein, supramolecular chemistry is combined with the AIEgen bis‐pyrene (BP) to construct a peptide–AIEgen hybrid nanosystem (PAHN). After intravenous injection, the versatile nanoplatform not only improved the hydrophilicity of BP but also achieved stratified targeting from tumor to mitochondrial and induced mitochondrial dysfunction, thus activating caspase‐3 upregulation. Then, sonodynamic therapy (SDT), an alternative modality with high tissue penetrability, is performed to evoke reactive oxygen species (ROS) generation for BP. More importantly, since the hydrophilic shell is separated from the nanosystem by the specific cleavage of caspase‐3, the resulting decrease in hydrophilicity induced tight self‐aggregation of PAHN residues in situ, further allowing more absorbed energy to be used for ROS generation under ultrasound irradiation and enhancing SDT efficacy. Moreover, severe oxidative stress resulting from ROS imbalance in the mitochondria initiates the immunogenic cell death process, thus evoking antitumor immunogenicity. This PAHN provides prospective ideas into AIE‐involved antitumor therapy and design of peptide‐AIEgens hybrids.
Bifunctional Manipulation of Terahertz Waves with High‐Efficiency Transmissive Dielectric Metasurfaces
Authors: Wang Zhuo , Yao Yao , Pan Weikang , Zhou Haoyang , Chen Yizhen , Lin Jing , Hao Jiaming , Xiao Shiyi , He Qiong , Sun Shulin , Zhou Lei
Published: December 2022

Multifunctional terahertz (THz) devices in transmission mode are highly desired in integration‐optics applications, but conventional devices are bulky in size and inefficient. While ultra‐thin multifunctional THz devices are recently demonstrated based on reflective metasurfaces, their transmissive counterparts suffer from severe limitations in efficiency and functionality. Here, based on high aspect‐ratio silicon micropillars exhibiting wide transmission‐phase tuning ranges with high transmission‐amplitudes, a set of dielectric metasurfaces is designed and fabricated to achieve efficient spin‐multiplexed wavefront controls on THz waves. As a benchmark test, the photonic‐spin‐Hall‐effect is experimentally demonstrated with a record high absolute efficiency of 92% using a dielectric metasurface encoded with geometric phases only. Next, spin‐multiplexed controls on circularly polarized THz beams (e.g., anomalous refraction and focusing) are experimentally demonstrated with experimental efficiency reaching 88%, based on a dielectric meta‐device encoded with both spin‐independent resonant phases and spin‐dependent geometric phases. Finally, high‐efficiency spin‐multiplexed dual holographic images are experimentally realized with the third meta‐device encoded with both resonant and geometric phases. Both near‐field and far‐field measurements are performed to characterize these devices, yielding results in agreement with full‐wave simulations. The study paves the way to realize multifunctional, high‐performance, and ultra‐compact THz devices for applications in biology sensing, communications, and so on.
Recent Advances of Transition Metal Sulfides/Selenides Cathodes for Aqueous Zinc‐Ion Batteries
Authors: Shuai Honglei , Liu Renzhi , Li Wenxuan , Yang Xiaojian , Lu Hui , Gao Yongping , Xu Jing , Huang Kejing
Published: December 2022

Rechargeable aqueous zinc‐ion batteries (ZIBs) have aroused tremendous attention in energy storage system due to their high safety, eco‐friendliness, low cost, and for their good compatibility. Transition metal sulfides and selenides are considered to be promising cathodes for aqueous ZIBs owing to their unique layered structure and tunable interlayer spacing for the accelerating diffusion and reversible intercalation of hydrated Zn2+. However, their practical applications are severely impeded by some defects, such as the inferior electronic conductivity, large ion diffusion energy barrier, and bad cyclic stability. In this review, the various modification strategies including phase engineering, defect engineering, interlayer intercalation, in situ electrochemical oxidation, hybridization, doping effects, and surface modification are categorized and highlighted to improve the electrochemical properties of transition metal sulfides and selenides cathode materials, which are discussed and summarized corresponding to particular modification strategies. Finally, several key breakthrough directions such as mechanism exploration technology, electrolyte strategies, synergistic engineering, high‐capacity conversion‐type, high‐voltage cathode materials, and rocking‐chair type batteries are proposed to further push forward the development of aqueous ZIBs, to guide the design of advanced‐properties cathode materials for aqueous ZIBs.
Is Nonflammability of Electrolyte Overrated in the Overall Safety Performance of Lithium Ion Batteries? A Sobering Revelation from a Completely Nonflammable Electrolyte
Authors: Jia Hao , Yang Zhijie , Xu Yaobin , Gao Peiyuan , Zhong Lirong , Kautz David J. , Wu Dengguo , Fliegler Ben , Engelhard Mark H. , Matthews Bethany E. , Broekhuis Benjamin , Cao Xia , Fan Jiang , Wang Chongmin , Lin Feng , Xu Wu
Published: December 2022

It has been widely assumed that the flammability of the liquid electrolyte is one of the most influential factors that determine the safety of lithium‐ion batteries (LIBs). Following this consideration, a completely nonflammable electrolyte is designed and adopted for graphite||LiFePO4 (Gr||LFP) batteries. Contrary to the conventional understanding, the completely nonflammable electrolyte with phosphorus‐containing solvents exhibits inferior safety performance in commercial Gr||LFP batteries, in comparison to the flammable conventional LiPF6‐organocarbonate electrolyte. Mechanistic studies identify the exothermic reactions between the electrolyte (especially the salt LiFSI) and the charged electrodes as the “culprit” behind this counterintuitive phenomenon. The discovery emphasizes the importance of reducing the electrolyte reactivity when designing safe electrolytes, as well as the necessity of evaluating safety performance of electrolytes on a battery level.
Thermal Activation of PEDOT:PSS/PM6:Y7 Based Films Leads to Unprecedent High Short‐Circuit Current Density in Nonfullerene Organic Photovoltaics
Authors: Moustafa Enas , Méndez Maria , Sánchez José G. , Pallarès Josep , Palomares Emilio , Marsal Lluis F.
Published: December 2022

Finding an effective approach to suppress trap formation is a potential route for enhancing the performance of nonfullerene organic photovoltaic (NF‐OPVs) devices. Here, an extraordinary short‐circuit current density (JSC) value of 32.65 mA cm‐2 is achieved, higher than the state‐of‐the art NF‐OPVs reported, reaching a high power conversion efficiency (PCE) of 17.92%. This remarkable enhancement is exhibited through the fine‐tuning of PEDOT:PSS/PM6:Y7 films and interface morphologies via applying the prethermal treatment approach (Pre‐TT) to the devices, which exhibit JSC and PCE enhancement of 21% and 8%, respectively, compared to the pristine devices. Accordingly, the dependence of the JSC upon the Pre‐TT approach through a range of morphological, optical, electrical, and advanced transient measurements is investigated. The Pre‐TT‐based films are found to possess optimal smooth blend morphology with better dispersity owing to reduced domain size. Moreover, the measurements show that the optimized treated devices present higher exciton dissociation probabilities and generation rate of the free charge carriers, showing an ideal balanced electron/hole mobility that reveals the JSC and PCE enhancement. Hence, Pre‐TT approach provides a facile passivation strategy that reduces the trap state density of the blend film, improves interface charge transfer, allows balanced electron/hole mobility, and thus promotes device performance.
Device Performance of Emerging Photovoltaic Materials (Version 3)
Authors: Almora Osbel , Baran Derya , Bazan Guillermo C. , Cabrera Carlos I. , Erten‐Ela Sule , Forberich Karen , Guo Fei , Hauch Jens , Ho‐Baillie Anita W. Y. , Jacobsson T. Jesper , Janssen Rene A. J. , Kirchartz Thomas , Kopidakis Nikos , Loi Maria A. , Lunt Richard R. , Mathew Xavier , McGehee Michael D. , Min Jie , Mitzi David B. , Nazeeruddin Mohammad K. , Nelson Jenny , Nogueira Ana F. , Paetzold Ulrich W. , Rand Barry P. , Rau Uwe , Snaith Henry J. , Unger Eva , Vaillant‐Roca Lídice , Yang Chenchen , Yip Hin‐Lap , Brabec Christoph J.
Published: December 2022

Following the 2nd release of the “Emerging PV reports,” the best achievements in the performance of emerging photovoltaic devices in diverse emerging photovoltaic research subjects are summarized, as reported in peer‐reviewed articles in academic journals since August 2021. Updated graphs, tables, and analyses are provided with several performance parameters, e.g., power conversion efficiency, open‐circuit voltage, short‐circuit current density, fill factor, light utilization efficiency, and stability test energy yield. These parameters are presented as a function of the photovoltaic bandgap energy and the average visible transmittance for each technology and application, and are put into perspective using, e.g., the detailed balance efficiency limit. The 3rd installment of the “Emerging PV reports” extends the scope toward triple junction solar cells.
Flexible Freestanding Thin Polyethylene Oxide‐Based Film as Artificial Solid–Electrolyte Interface to Protect Lithium Metal in Lithium–Sulfur Batteries
Authors: Grotkopp Nico Lars , Horst Marcella , Batzer Mattis , Garnweitner Georg , Jean-Fulcrand Annelise
Published: December 2022

Lithium–sulfur batteries (LSBs) that utilize sulfur and lithium (Li) metal as electrode materials are highly attractive for transportation applications due to their high theoretical gravimetric energy density. However, two major challenges currently impede the commercialization of LSB, which are the formation of Li dendrites and polysulfide shuttling. To mitigate these two effects, a protective film or artificial solid–electrolyte interface (SEI) can be applied directly to the Li‐metal surface. Herein, the preparation of freestanding polyethylene oxide (PEO)‐based films using tape casting as a scalable coating technique is presented. Moreover, the films are applied directly to the Li surface via a solvent‐free method. To demonstrate the suitability of the developed PEO‐based films, the long‐term cycling performance of the lithium–sulfur cells is discussed. It is shown that the cells with the Li‐metal surface protected by PEO‐based films achieve better stability and reproducibility, reaching ≈400 mA h g S−1 after 250 cycles compared to ≈200 mA h g S−1 after 250 cycles for the bare Li‐metal electrode. An extensive postmortem analysis of the Li‐metal electrode surface with scanning electron microscopy is additionally shown, revealing that the PEO‐based artificial SEIs form uniformly with a low level of defect layers at the interface with the Li‐metal electrode, which indicates the creation of a stable SEI.