bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonmetallic Materials for Plasmonic Hot Carrier Excitation
Authors: Ishii Satoshi , Shinde Satish Laxman , Nagao Tadaaki 
Published: October 2018

AbstractOptical excitation of hot carriers in metals can be achieved even with low energy photons. When a metal comes in contact with a semiconductor, carrier injection can take place from the metal to the semiconductor even with photons possessing sub‐bandgap energies. While such internal photoemission has several decades of history, recent advances in plasmonics have brought the study of internal photoemission into a new era. The efficiency of hot carrier excitation can be improved drastically by rationally fabricating a metallic nanostructure to excite plasmon resonances. Moreover, the heating caused by the relaxation of plasmonic hot carriers is highly localized. These plasmon enhanced photoelectric and photothermal conversions have been studied intensively from fundamental and application‐oriented viewpoints, wherein gold and silver have been exclusively used. By contrast, this progress report covers nonmetallic materials that can be used for plasmon enhanced photoelectric and photothermal conversions. The main nonmetallic materials covered herein are transition metal nitrides, transition metal carbides, and metal oxides. Although research on nonmetallic materials for photoelectric and photothermal conversions is in the preliminary stage, some nonmetallic materials have been shown to outperform gold. This progress report aims to highlight the recent progress and discuss future research directions.
Designer Perfect Light Absorption Using Ultrathin Lossless Dielectrics on Absorptive Substrates
Authors: ElKabbash Mohamed , Iram Shamreen , Letsou Theodore , Hinczewski Michael , Strangi Giuseppe 
Published: October 2018

AbstractOptical absorbers comprised of an ultrathin lossy dielectric film on an opaque metallic substrate are an attractive alternative to lithographically intense metamaterial and nanoplasmonic optical absorbers as they allow for large‐scale, cost‐effective fabrication. However, requiring that the dielectric is lossy and the metallic substrate is highly reflective but not a perfect electric conductor (PEC) limits the wavelength range and materials that can be used to realize strong to perfect light absorption. In this work, we theoretically and experimentally investigate light absorption using ultrathin lossless dielectric films. By choosing proper lossless ultrathin dielectrics and substrates, iridescence free, perfect light absorption is possible over the visible, near infrared (NIR), and short‐wave infrared (SWIR) wavelength ranges with designer absorption properties. The proposed class of ultrathin film absorbers relaxes many constraints on the type of materials used to realize perfect light absorption. The flexibility of our design makes it relevant for many applications specifically in structural coloring, selective thermal emission, thermo‐photovoltaics, photo‐thermoelectric generation, and gas sensing.
Electrical Control of Unpolarized Reflectivity in Polymer‐Stabilized Cholesteric Liquid Crystals at Oblique Incidence
Authors: Tondiglia Vincent P. , Rumi Mariacristina , Idehenre Ighodalo U. , Lee Kyung Min , Binzer John F. , Banerjee Partha P. , Evans Dean R. , McConney Michael E. , Bunning Timothy J. , White Timothy J. 
Published: October 2018

AbstractThe cholesteric liquid crystal phase at or near normal incidence selectively reflects circularly polarized light matching the handedness of the helicoidal superstructure. At large angles of incidence, both senses of circularly polarized light are reflected over a certain wavelength range. Stabilizing the cholesteric liquid crystal phase with low concentrations of polymer network that maintains structural chirality allows the pitch (and accordingly, the selective reflection) to be adjusted with an electric field. Here, the behavior of these polymer stabilized cholesteric liquid crystals is investigated at large angles of incidence, to determine how the total reflection evolves when the polymer network is deformed by an external DC field. Strong, unpolarized reflection is observed in polymer stabilized cholesteric liquid crystals at oblique angles over a wide range of field values. As the application of a DC electric field can adjust the position or bandwidth of the total reflection in polymer stabilized cholesteric liquid crystals, these reconfigurable devices could find potential end use in optical applications where polarization independent properties are needed, such as spectroscopy and polarimetry.
Liquid Crystal Pancharatnam–Berry Micro‐Optical Elements for Laser Beam Shaping
Authors: Jiang Miao , Yu Hao , Feng Xiayu , Guo Yubing , Chaganava Irakli , Turiv Taras , Lavrentovich Oleg D. , Wei Qi‐Huo 
Published: October 2018

AbstractShaping the intensity profile of a laser beam is desired by various industrial applications. In this paper, a new approach is presented to design and fabricate liquid crystal (LC) micro‐optical elements (MOEs) with engineered Pancharatnam–Berry (PB) phases for beam shaping. By generalizing the Snell's law for spatially variant PB phases, molecular orientation patterns are designed for the liquid crystal MOEs to shape a Gaussian laser beam into flattop intensity profiles with circular and square cross‐sections, with the β parameter varied from 4 to 42. It is demonstrated that such liquid crystal beam shaping MOEs can be fabricated with high throughput and high resolution by using a photopatterning technique based on plasmonic metamasks and that they produce excellent beam quality, no zero‐order light leakage with a beam size from 10 to 600 µm. As the plasmonic metamasks allow for encoding arbitrary molecular orientations, i.e., arbitrary geometric phase profiles, the approaches presented here are widely applicable to large‐scale manufacturing of liquid crystal MOEs for any beam shapes.
Advances in Porous Silicon–Based Nanomaterials for Diagnostic and Therapeutic Applications
Authors: Tieu Terence , Alba Maria , Elnathan Roey , Cifuentes‐Rius Anna , Voelcker Nicolas H. 
Published: October 2018

AbstractThis review provides a perspective on porous silicon (pSi)–based nanomaterials including nanoparticles, nanowires, and thin films, that are currently being used in advanced therapy, imaging, and sensing, with a focus on their effective use in future clinical settings. The achievement of both controlled geometry and architecture, and surface chemistry motifs, are presented as the two key parameters that dictate the nature of interactions with the biological entities. The authors discuss the role of the degradation kinetics in a biological environment into nontoxic by‐products. pSi is presented as increasingly fulfilling a central task in various biomedical applications and clinical settings, owing to its unique physiochemical properties.
Modeling of Soft Sample Deformation in Atomic Force Microscope Imaging: Live Mammalian Cell Example
Authors: Ren Juan , Zou Qingze 
Published: October 2018

AbstractA model of the scanning‐caused soft sample deformation during atomic force microscope contact‐mode (CM) imaging is developed. CM imaging has been widely used for topography characterization of live biological samples such as live cells. However, due to the intrinsic softness of these samples, the sample surface deformation caused by the probe–sample interaction leads to significant error in the topography images obtained, and damage to the live biological sample. Although the deformation can be reduced by imaging at a rather slow scan rate (e.g., less than 0.2 Hz), such a low‐speed imaging not only is time consuming, but also inevitably induces large temporal error. In this work, the scanning‐caused surface deformation of soft samples is modeled and quantified, including live biological samples in CM imaging. Effects of both the scanning and the coupling between the vertical and the lateral deformation on the deformation are characterized. The proposed deformation model is validated by implementing it to quantify the topography image difference caused by the scanning‐caused surface deformation of live prostate cancer cells imaged at two different (high and low) speeds, respectively.
Designing Magnetic Anisotropy through Strain Doping
Authors: Herklotz Andreas , Gai Zheng , Sharma Yogesh , Huon Amanda , Rus Stefania F. , Sun Lu , Shen Jian , Rack Philip D. , Ward Thomas Z. 
Published: October 2018

AbstractThe coupling between a material's lattice and its underlying spin state links structural deformation to magnetic properties; however, traditional strain engineering does not allow the continuous, post‐synthesis control of lattice symmetry needed to fully utilize this fundamental coupling in device design. Uniaxial lattice expansion induced by post‐synthesis low energy helium ion implantation is shown to provide a means of bypassing these limitations. Magnetocrystalline energy calculations can be used a priori to estimate the predictive design of a material's preferred magnetic spin orientation. The efficacy of this approach is experimentally confirmed in a spinel CoFe2O4 model system where the epitaxial film's magnetic easy axis is continuously manipulated between the out‐of‐plane (oop) and in‐plane (ip) directions as lattice tetragonality moves from ip to oop with increasing strain doping. Macroscopically gradual and microscopically abrupt changes to preferential spin orientation are demonstrated by combining ion irradiation with simple beam masking and lithographic procedures. The ability to design magnetic spin orientations across multiple length scales in a single crystal wafer using only crystal symmetry considerations provides a clear path toward the rational design of spin transfer, magnetoelectric, and skyrmion‐based applications where magnetocrystalline energy must be dictated across multiple length scales.
Jammed Microgel Inks for 3D Printing Applications
Authors: Highley Christopher B. , Song Kwang Hoon , Daly Andrew C. , Burdick Jason A. 
Published: October 2018

Abstract3D printing involves the development of inks that exhibit the requisite properties for both printing and the intended application. In bioprinting, these inks are often hydrogels with controlled rheological properties that can be stabilized after deposition. Here, an alternate approach is developed where the ink is composed exclusively of jammed microgels, which are designed to incorporate a range of properties through microgel design (e.g., composition, size) and through the mixing of microgels. The jammed microgel inks are shear‐thinning to permit flow and rapidly recover upon deposition, including on surfaces or when deposited in 3D within hydrogel supports, and can be further stabilized with secondary cross‐linking. This platform allows the use of microgels engineered from various materials (e.g., thiol‐ene cross‐linked hyaluronic acid (HA), photo‐cross‐linked poly(ethylene glycol), thermo‐sensitive agarose) and that incorporate cells, where the jamming process and printing do not decrease cell viability. The versatility of this particle‐based approach opens up numerous potential biomedical applications through the printing of a more diverse set of inks.
The Relation of Phase‐Transition Effects and Thermal Stability of Planar Perovskite Solar Cells
Authors: Qin Chuanjiang , Matsushima Toshinori , Klotz Dino , Fujihara Takashi , Adachi Chihaya 
Published: October 2018

AbstractA power conversion efficiency of over 20% has been achieved in CH3NH3PbI3‐based perovskite solar cells (PSC), however, low thermal stability associated with the presence of a phase transition between tetragonal and cubic structures near room temperature is a major issue that must be overcome for future practical applications. Here, the influence of the phase transition on the thermal stability of PSCs is investigated in detail by comparing four kinds of perovskite films with different compositions of halogen atoms and organic components. Thermally stimulated current measurements reveal that a large number of carrier traps are generated in solar cells with the perovskite CH3NH3PbI3 as a light absorber after operation at 85 °C, which is higher than the phase‐transition temperature. Electrochemical impedance spectroscopy measurements further exclude effects of a possible morphology change on the formation of carrier traps. These carrier traps are detrimental to the thermal stability. The thermogravimetric analysis does not show a decomposition for any of the materials in the temperature range relevant for operation. The perovskite alloys do not have this phase transition, resulting in effectively suppressed formation of carrier traps. PSCs with improved thermal stability under the standard thermal cycling test are demonstrated.
Porous Organic Frameworks: Advanced Materials in Analytical Chemistry
Authors: Zhang Shuaihua , Yang Qian , Wang Chun , Luo Xiliang , Kim Jeonghun , Wang Zhi , Yamauchi Yusuke 
Published: October 2018

AbstractPorous organic frameworks (POFs), a general term for covalent‐organic frameworks (COFs), covalent triazine frameworks (CTFs), porous aromatic frameworks (PAFs), etc., are constructed from organic building monomers with strong covalent bonds and have generated great interest among researchers. The remarkable features, such as large surface areas, permanent porosity, high thermal and chemical stability, and convenient functionalization, promote the great potential of POFs in diverse applications. A critical overview of the important development in the design and synthesis of COFs, CTFs, and PAFs is provided and their state‐of‐the‐art applications in analytical chemistry are discussed. POFs and their functional composites have been explored as advanced materials in “turn‐off” or “turn‐on” fluorescence detection and novel stationary phases for chromatographic separation, as well as a promising adsorbent for sample preparation methods. In addition, the prospects for the synthesis and utilization of POFs in analytical chemistry are also presented. These prospects can offer an outlook and reference for further study of the applications of POFs.
A Facile Approach to Improve Interchain Packing Order and Charge Mobilities by Self‐Assembly of Conjugated Polymers on Water
Authors: Yang Yizhou , Liu Zitong , Chen Jianmei , Cai Zhengxu , Wang Zhijie , Chen Wei , Zhang Guanxin , Zhang Xisha , Chi Lifeng , Zhang Deqing 
Published: October 2018

AbstractDevelopment of facile and economic approaches for assembling organic semiconductors into more ordered structures toward high charge mobilities is highly demanding for the fabrication of organic circuits. Here a simple and facile approach is reported to prepare conjugated polymer thin films with improved crystallinities and charge mobilities by self‐assembling semiconducting polymers on water. The formation of polymer thin films with more ordered structures is attributed to coffee ring effect induced by solvent‐evaporation on water, and the hydrophobic nature of conjugated polymers that forces the polymer chains to pack densely and orderly on water surface. This approach is applicable to typical semiconducting polymers, and charge mobilities of their thin films are boosted remarkably. Finally, this new method can be utilized to easily fabricate the array of field‐effect transistors with high charge mobilities in an economic way.
Solution‐Processed InAs Nanowire Transistors as Microwave Switches
Authors: Mirkhaydarov Bobur , Votsi Haris , Sahu Abhishek , Caroff Philippe , Young Paul R. , Stolojan Vlad , King Simon G. , Ng Calvin C. H. , Devabhaktuni Vijaya , Tan Hoe H. , Jagadish Chennupati , Aaen Peter H. , Shkunov Maxim 
Published: October 2018

AbstractThe feasibility of using self‐assembled InAs nanowire bottom‐gated field‐effect transistors as radio‐frequency and microwave switches by direct integration into a transmission line is demonstrated. This proof of concept is demonstrated as a coplanar waveguide (CPW) microwave transmission line, where the nanowires function as a tunable impedance in the CPW through gate biasing. The key to this switching capability is the high‐performance, low impedance InAs nanowire transistor behavior with field‐effect mobility of ≈300 cm2 V−1 s−1, on/off ratio of 103, and resistance modulation from only 50 Ω in the full accumulation mode, to ≈50 kΩ when the nanowires are depleted of charge carriers. The gate biasing of the nanowires within the CPW results in a switching behavior, exhibited by a ≈10 dB change in the transmission coefficient, S21, between the on/off switching states, over 5–33 GHz. This frequency range covers both the microwave and millimeter‐wave bands dedicated to Internet of things and 5G applications. Demonstration of these switches creates opportunities for a new class of devices for microwave applications based on solution‐processed semiconducting nanowires.
Selective CO2 Reduction on 2D Mesoporous Bi Nanosheets
Authors: Yang Hui , Han Na , Deng Jun , Wu Jinghua , Wang Yu , Hu Yongpan , Ding Pan , Li Yafei , Li Yanguang , Lu Jun 
Published: October 2018

AbstractThe conversion of CO2 to value‐added products using electrical or solar energy represents an attractive means for the capture and utilization of atmospheric CO2. Formate is a popular product from CO2 reduction, but its reaction selectivity is usually unsatisfactory. Tin‐based materials have attracted the most attention for formate production at present. Unfortunately, most of them only exhibit moderate selectivity in a narrow and highly cathodic potential window. In this study, it is demonstrated that traditionally under‐explored bismuth has a much greater potential for formate production than tin or other materials. Mesoporous bismuth nanosheets are prepared here by the cathodic transformation of atomic‐thick bismuth oxycarbonate nanosheets. They enable the selective CO2 reduction to formate with large current density, excellent Faradaic efficiency (≈100%) over a broad potential window and great operation stability. Moreover, Bi nanosheets are integrated with an oxygen evolution reaction electrocatalyst in full cells, and achieve efficient and robust solar conversion of CO2/H2O to formate/O2.
High‐Rate Performance and Ultralong Cycle Life Enabled by Hybrid Organic–Inorganic Vanadyl Ethylene Glycolate for Lithium‐Ion Batteries
Authors: Wang Xinran , Bi Xuanxuan , Zheng Shili , Wang Shaona , Zhang Yi , Du Hao , Lu Jun 
Published: October 2018

AbstractTransition metal oxides (TMOs) possess high theoretical capacity and serve as promising anode candidates for lithium‐ion batteries. However, the intrinsic low conductivity handicaps the application of TMOs. Molecular modification by coupling TMOs structure with Li‐ion conductive polymer ligands can facilitate the kinetics of electrochemical lithiation/delithiation process. Herein, a proof‐of‐concept investigation on the Li‐ion storage capability by vanadyl ethylene glycolate (VEG) is achieved with the improvement of Li‐ion diffusion kinetics by modifiying the vanadium oxide with organic ligands. VEG demonstrates unprecedented advantage for fast rate capability, stable cycleability, and high capacity at both room temperarture (25 °C) and elevated temperature (60 °C).
Synergistic High‐Rate Solar Steaming and Mercury Removal with MoS2/C @ Polyurethane Composite Sponges
Authors: Li Weigu , Tekell Marshall C. , Huang Yun , Bertelsmann Karina , Lau Max , Fan Donglei 
Published: October 2018

AbstractSolar steam generation, a sustainable water‐purification technology, holds substantial promise in resolving the global issue of shortage of drinkable water. Here, the design, fabrication, and high‐performance of an innovative 3D solar steamer, offering synergistic high‐efficiency steaming and heavy metal removal functions are reported. The device is made of synthesized carbon‐molybdenum‐disulfide microbeads electrostatically assembled on a 3D polyurethane sponge. The mesoporous composite sponge also serves as a freestanding water reservoir that avoids one‐side contact to bulk water, effectively suppressing the commonly observed parasitic heat loss, and offering a high energy efficiency of 88%. When being sculpted into a 3D spoke‐like structure, the composite sponge achieves one of the highest evaporation rates of 1.95 kg m−2 h−1 at 1 sun. The solar steamer is demonstrated for water treatment, i.e., decontamination of metal ions, disinfection, and reducing alkalinity and hardness of river water. Particularly, the strong mercury adsorption of MoS2 reduces mercury levels from 200 to 1 ppb, meeting the stringent standard set by the Environmental Protection Agency, which is the first demonstration of mercury‐removal powered by solar energy. The unique design, fabrication, water‐handling strategy, and mercury‐removal function of this high‐performance solar steamer can inspire new paradigms of water treatment technologies.
Direct Electricity Generation Mediated by Molecular Interactions with Low Dimensional Carbon Materials—A Mechanistic Perspective
Authors: Liu Albert Tianxiang , Zhang Ge , Cottrill Anton L. , Kunai Yuichiro , Kaplan Amir , Liu Pingwei , Koman Volodymyr B. , Strano Michael S. 
Published: October 2018

AbstractNext‐generation off‐the‐grid electronic systems call for alternative modes of energy harvesting. The past two decades have witnessed the evolution of a wide spectrum of low dimensional carbon materials with extraordinary physical and chemical properties, ideal for microscale electrical energy storage and generation. Tremendous progress has been made in harnessing the energy associated with the interactions between these nanostructured carbon substrates and the surrounding molecular phases, subsequently converting them into useful electricity. This review summarizes the important theoretical and experimental milestones the field has reached to date, and further classifies these energy harvesting processes based on underlying physics, into five mechanistically distinct classes—phonon coupling, Coulombic scattering, electrokinetic streaming, asymmetric doping, and capacitive discharging. With a special mechanistic focus, the authors hope to resolve the fundamental attributes shared by this diverse array of molecular scale energy harvesting schemes, offer perspectives on key challenges, and ultimately establish design principles that guide further device optimization.
Effect of Heteroatom and Doping on the Thermoelectric Properties of Poly(3‐alkylchalcogenophenes)
Authors: Gregory Shawn A. , Menon Akanksha K. , Ye Shuyang , Seferos Dwight S. , Reynolds John R. , Yee Shannon K. 
Published: October 2018

AbstractThis study reports on the thermoelectric properties of poly(3‐alkylchalcogenophene) thin films (500 nm) as a function of heteroatom (sulfur, selenium, tellurium), and how these properties change with dopant (ferric chloride) concentration. UV–vis–NIR spectroscopy shows that polaronic charge carriers are formed upon doping. Poly(3‐alkyltellurophene) (P3RTe) is most easily doped followed by poly(3‐alkylselenophene) (P3RSe) and poly(3‐alkylthiophene) (P3RT), where R = 3,7‐dimethyloctyl chain is the pendant alkyl group. Thermoelectric properties vary as functions of the heteroatom and doping level. At low dopant concentrations (≈1 × 10−3
m), P3RTe shows the highest power factor of 10 µW m−1 K−2, while, at higher dopant concentrations (≈5 × 10−3
m), P3RSe shows the highest power factor of 13 µW m−1 K−2. Most notably, it is found that the measured properties are consistent with Mott's polaron hopping model and not consistent with other transport models. Additionally, temperature‐dependent conductivity measurements show that for a given dopant concentration, the activation energies for electronic transport decrease as the heteroatom is changed from sulfur to selenium to tellurium. Overall, this work presents a systematic study of poly(chalcogenophenes) and indicates the potential of polymers beyond P3HT by tuning the heteroatom and doping level for optimized thermoelectric performance.