bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Breathable and Screen‐Printed Pressure Sensor Based on Nanofiber Membranes for Electronic Skins
Authors: Yang Wei , Li Nian‐Wu , Zhao Shuyu , Yuan Zuqing , Wang Jiaona , Du Xinyu , Wang Bin , Cao Ran , Li Xiuyan , Xu Weihua , Wang Zhong Lin , Li Congju 
Published: December 2017

AbstractIn recent years, skin‐like pressure sensors with high sensitivity and excellent flexibility are widely demonstrated for electronic skins. However, most of the reported skin‐like pressure sensors are still based on airtight films, resulting in limited air permeability. Herein, cost‐effective and capable processes of large‐scale production are reported for lightweight and breathable pressure sensors based on nanofiber membranes (NM). The pressure sensor is composed of a layer‐by‐layer structure of poly(vinylidene fluoride) NM for substrates, silver nanowires for electrodes, and thermoplastic polyurethane NM for the dielectric layer through screen printing and ultrasonic bonding techniques. Benefiting from the high porosity of NM, the capacitive pressure sensor possesses unique performance, including a superior sensitivity of 4.2 kPa−1, a fast response time (<26 ms), an ultralow detection limit (1.6 Pa), and excellent breathability (Gurley value = 17.3 s/100 mL). Furthermore, the pressure sensor is not only applicable to monitor human physiological signals, but also to detect spatial pressure distribution. These results indicate that the breathable and screen‐print pressure sensor is promising for electronic skins with air permeability.
Interactive Nanogel Marking at the Microscale for Security and Traceability Applications
Authors: Teulon Lauryanne , Palleau Etienne , Morales Daniel , Poirot David , Ressier Laurence 
Published: December 2017

AbstractAn original approach named Nanogel Marking is addressed herein to propose new alternatives to fight counterfeiting and forgery by improving the traceability of objects and documents and enabling secured authentication. This technique can be used to write or code information, logos, or patterns of a desired design at the microscale using poly(NIPAAm‐co‐AAc) nanogels as an envirointelligent biocompatible “ink.” Nanogel marking features multiple functions, such as reversibility (write/erase properties), color changing capabilities, and recycling capabilities. Based on soft lithography methods, this nanogel marking technique also overcomes industrial limitations since it is fast, sustainable, and scalable on surfaces as large as a 4 in. wafer, enabling the fabrication of hundreds of thousands of nanogel markers in a few minutes.
Printing of Large‐Scale, Flexible, Long‐Term Stable Dielectric Mirrors with Suppressed Side Interferences
Authors: Bronnbauer Carina , Riecke Arne , Adler Marius , Hornich Julian , Schunk Gerhard , Brabec Christoph J. , Forberich Karen 
Published: December 2017

AbstractDielectric mirrors are wavelength‐selective mirrors which are based on thin film interference effects. Their optical band can precisely be adjusted in width, position, and reflectance by the refractive index of the applied materials, the layers' thicknesses, and the amount of deposited layers. Nowadays, they are a well‐known light management tool for efficiency enhancement in, for example, semitransparent organic solar cells (OSCs) and light guiding in organic light‐emitting diodes (OLEDs). However, most of the dielectric mirrors are still fabricated by lab‐scale techniques such as spin‐coating or physical vapor deposition under vacuum. Large‐scale, fully printed (maximum 20 × 20 cm2) dielectric mirrors with adjustable reflectance characteristics are fabricated, using temperatures of maximum 50 °C and alcohol‐based inks. According to the moderate processing conditions they can be easily deposited not only on rigid glass substrates but also on flexible foils. They show high stability against humidity, light irradiation, and temperature, positioning themselves as good candidates for applications in OLEDs and OSCs. Eventually, by simulations and experiments it is verified that a moderate degree of variations in layer thickness and surface roughness can suppress side interference fringes, while not impacting the main transmittance minimum or the main reflection maximum, respectively.
Programming Photoresponse in Liquid Crystal Polymer Actuators with Laser Projector
Authors: Wani Owies M. , Zeng Hao , Wasylczyk Piotr , Priimagi Arri 
Published: December 2017

AbstractA versatile, laser‐projector‐based method is demonstrated for programming alignment patterns into monolithic films of liquid crystal polymer networks. Complex images can be photopatterned into the polymer films with sub‐100 µm resolution, using relatively short exposure times. The method is further used to devise both photochemically and photothermally driven actuators that can undergo distinct light‐induced shape changes, dictated by the programmed alignment patterns. Deformation modes such as buckling and coiling, as well as miniature robotic devices such as a gripper and a light‐responsive octopod, are demonstrated. The reported technique enables easy and cost‐effective programmable actuation with relatively high throughput, thus significantly facilitating the design and realization of functional soft robotic actuators.
Dopant‐Free and Carrier‐Selective Heterocontacts for Silicon Solar Cells: Recent Advances and Perspectives
Authors: Gao Pingqi , Yang Zhenhai , He Jian , Yu Jing , Liu Peipei , Zhu Juye , Ge Ziyi , Ye Jichun 
Published: December 2017

AbstractBy combining the most successful heterojunctions (HJ) with interdigitated back contacts, crystalline silicon (c‐Si) solar cells (SCs) have recently demonstrated a record efficiency of 26.6%. However, such SCs still introduce optical/electrical losses and technological issues due to parasitic absorption/Auger recombination inherent to the doped films and the complex process of integrating discrete p+‐ and n+‐HJ contacts. These issues have motivated the search for alternative new functional materials and simplified deposition technologies, whereby carrier‐selective contacts (CSCs) can be formed directly with c‐Si substrates, and thereafter form IBC cells, via a dopant‐free method. Screening and modifying CSC materials in a wider context is beneficial for building dopant‐free HJ contacts with better performance, shedding new light on the relatively mature Si photovoltaic field. In this review, a significant number of achievements in two representative dopant‐free hole‐selective CSCs, i.e., poly(3,4‐ethylene dioxythiophene):poly(styrenesulfonate)/Si and transition metal oxides/Si, have been systemically presented and surveyed. The focus herein is on the latest advances in hole‐selective materials modification, interfacial passivation, contact resistivity, light‐trapping structure and device architecture design, etc. By analyzing the structure–property relationships of hole‐selective materials and assessing their electrical transport properties, promising functional materials as well as important design concepts for such CSCs toward high‐performance SCs have been highlighted.
Nanogap‐Engineerable Electromechanical System for Ultralow Power Memory
Authors: Zhang Jian , Deng Ya , Hu Xiao , Nshimiyimana Jean Pierre , Liu Siyu , Chi Xiannian , Wu Pei , Dong Fengliang , Chen Peipei , Chu Weiguo , Zhou Haiqing , Sun Lianfeng 
Published: December 2017

AbstractNanogap engineering of low‐dimensional nanomaterials has received considerable interest in a variety of fields, ranging from molecular electronics to memories. Creating nanogaps at a certain position is of vital importance for the repeatable fabrication of the devices. Here, a rational design of nonvolatile memories based on sub‐5 nm nanogaped single‐walled carbon nanotubes (SWNTs) via the electromechanical motion is reported. The nanogaps are readily realized by electroburning in a partially suspended SWNT device with nanoscale region. The SWNT memory devices are applicable for both metallic and semiconducting SWNTs, resolving the challenge of separation of semiconducting SWNTs from metallic ones. Meanwhile, the memory devices exhibit excellent performance: ultralow writing energy (4.1 × 10−19 J bit−1), ON/OFF ratio of 105, stable switching ON operations, and over 30 h retention time in ambient conditions.
Ultrawide‐Bandgap Semiconductors: Research Opportunities and Challenges
Authors: Tsao J. Y. , Chowdhury S. , Hollis M. A. , Jena D. , Johnson N. M. , Jones K. A. , Kaplar R. J. , Rajan S. , Van de Walle C. G. , Bellotti E. , Chua C. L. , Collazo R. , Coltrin M. E. , Cooper J. A. , Evans K. R. , Graham S. , Grotjohn T. A. , Heller E. R. , Higashiwaki M. , Islam M. S. , Juodawlkis P. W. , Khan M. A. , Koehler A. D. , Leach J. H. , Mishra U. K. , Nemanich R. J. , Pilawa‐Podgurski R. C. N. , Shealy J. B. , Sitar Z. , Tadjer M. J. , Witulski A. F. , Wraback M. , Simmons J. A. 
Published: December 2017

AbstractUltrawide‐bandgap (UWBG) semiconductors, with bandgaps significantly wider than the 3.4 eV of GaN, represent an exciting and challenging new area of research in semiconductor materials, physics, devices, and applications. Because many figures‐of‐merit for device performance scale nonlinearly with bandgap, these semiconductors have long been known to have compelling potential advantages over their narrower‐bandgap cousins in high‐power and RF electronics, as well as in deep‐UV optoelectronics, quantum information, and extreme‐environment applications. Only recently, however, have the UWBG semiconductor materials, such as high Al‐content AlGaN, diamond and Ga2O3, advanced in maturity to the point where realizing some of their tantalizing advantages is a relatively near‐term possibility. In this article, the materials, physics, device and application research opportunities and challenges for advancing their state of the art are surveyed.
Role of the Electrode Material on the RESET Limitation in Oxide ReRAM Devices
Authors: Schönhals Alexander , Rosário Carlos M. M. , Hoffmann‐Eifert Susanne , Waser Rainer , Menzel Stephan , Wouters Dirk J. 
Published: December 2017

AbstractMetal‐oxide‐based bipolar resistive switching (BRS) redox‐based resistive switching memory (ReRAM) shows many outstanding properties making it of interest as an emerging nonvolatile memory. However, it often suffers from a low ROFF/RON ratio, while a large ratio is desired to compensate for read margin loss due to the intrinsic variability of the ReRAM cells. Understanding of the physical processes responsible for limitations of the ROFF and RON in ReRAM cells is therefore of high importance. In this paper a study on the RESET process in BRS Ta2O5‐based ReRAM cells is presented. The ROFF is found to be limited by a secondary volatile resistive switching mode that shows an opposite polarity compared to the main BRS mode. Based on results of switching kinetics measurements a physical model is proposed. It involves an oxygen exchange reaction at the metal‐oxide/active electrode interface combined with a drift‐diffusion induced migration of the resulting oxygen vacancy defects within the metal‐oxide. Incorporation of a thin oxygen‐blocking layer at the active interface allows for a suppression of the secondary switching mechanism. The improved RESET characteristic results in a strongly increased maximum ROFF. These results provide new insights into the role of the electrode material on the RESET process in BRS ReRAM cells.
Fine‐Tuned Multilayered Transparent Electrode for Highly Transparent Perovskite Light‐Emitting Devices
Authors: Wu Hua , Zhang Yu , Zhang Xiaoyu , Lu Min , Sun Chun , Bai Xue , Zhang Tieqiang , Sun Guang , Yu William W. 
Published: December 2017

AbstractThe high photoluminescence quantum yield, wide color tunability and narrow bandwidth of perovskite nanocrystals make them favorable for light source and display applications. Here, highly transparent green‐light‐emitting devices (LEDs) using inorganic cesium lead halide perovskite nanocrystal films as the emissive layer are reported. The effect of multilayered nanostructured transparent electrode on optical properties and performance within the LEDs is investigated by fine tuning layer thickness. The results show that the light transmission in visible region can be enhanced with this nanostructured film. These LEDs exhibited a high transmittance (average 73% over 400–700 nm) and high brightness of 2640 and 1572 cd m−2 for indium‐doped tin oxide (ITO) cathode and MoOx/Au/MoOx anode sides, respectively.
Sb2Se3 Thin‐Film Photovoltaics Using Aqueous Solution Sprayed SnO2 as the Buffer Layer
Authors: Lu Shuaicheng , Zhao Yang , Chen Chao , Zhou Ying , Li Dengbing , Li Kanghua , Chen Wenhao , Wen Xixing , Wang Chong , Kondrotas Rokas , Lowe Nathan , Tang Jiang 
Published: December 2017

AbstractSb2Se3 is a promising photovoltaic material due to its suitable bandgap, strong light absorption, simple phase, nontoxicity, and earth‐abundant constituents. Currently, most Sb2Se3 thin‐film solar cells are based on toxic CdS as the buffer layer. Here, for the first time, non‐toxic, wide‐bandgap, and chemically stable SnO2 is introduced as the buffer layer instead of CdS to build superstrate SnO2/Sb2Se3 thin‐film solar cells. The phase of sprayed SnO2 films and device band alignment are investigated in detail. SnO2 buffer layer annealed at 480 °C exhibits the lowest interfacial defect density and best device performance. Finally, 3.05% efficiency is achieved and the devices show excellent storage and light‐soaking stability. This preliminary experimental study implies that SnO2 has potential for developing high‐efficiency, stable, and environmentally friendly Sb2Se3‐based solar cells.
Self‐Assembly of Functionalized Oligothiophene into Hygroscopic Fibers: Fabrication of Highly Sensitive and Fast Humidity Sensors
Authors: Squillaci Marco A. , Cipriani Alessio , Melucci Manuela , Zambianchi Massimo , Caminati Grabriella , Samorì Paolo 
Published: December 2017

AbstractA new symmetric oligothiophene exposing tetraethylene glycol (TEG)‐based side‐chains is designed and synthesized. This molecule is found to self‐assemble in solution forming supramolecular fibers, via π–π stacking between the conjugated oligothiophene backbones, which are phase segregated on the sub‐nanometer scale from the TEG side‐groups. The delocalization of the charges through the oligothiophene π–π stack ensures efficient charge transport while the hygroscopic shell, decorating the surface of the fibrillar structures, determines a certain affinity for polar molecules. Upon exposure to humidity, under environmental conditions, such supramolecular architectures are capable of reversibly absorbing and desorbing water molecules. Absorption of water molecules, due to increased environmental humidity, causes a fast and reproducible increase of the electrical current through the fibers by a factor 100 from 15% to 90% relative humidity, as measured in 2‐terminal devices. Such process is extremely fast, taking place in less than 45 ms. The humidity‐responsive characteristics of the presented oligothiophene‐based fibers can be exploited for the facile fabrication of high‐performances and solution‐processable electrical resistive humidity sensors.
High‐Mobility Regioisomeric Thieno[f,f′]bis[1]benzothiophenes: Remarkable Effect of Syn/Anti Thiophene Configuration on Optoelectronic Properties, Self‐Organization, and Charge‐Transport Functions in Organic Transistors
Authors: Oyama Tatsuya , Mori Tatsuya , Hashimoto Tomohiro , Kamiya Muneaki , Ichikawa Takahiro , Komiyama Hideaki , Yang Yu Seok , Yasuda Takuma 
Published: December 2017

Abstractπ‐Conjugated thienoacene‐based organic semiconductors with high charge carrier mobility and processability have been intensively pursued for electronic device applications, including organic field‐effect transistors (OFETs). Their charge carrier mobility is an important figure of merit, and is influenced not only by the intrinsic electronic structure at molecular level, but also by the molecular packing arrangement and crystallinity in the solid state. In this work, the focus is on a unique regioisomeric thienoacene system involving dialkyl‐thieno[f,f′]bis[1]benzothiophene isomers having different syn/anti thiophene configurations (syn‐ and anti‐TBBT‐8). The effects of these regioisomeric structures on the physicochemical properties, self‐organization behavior, and charge‐transport functions are systematically investigated using experimental and theoretical analyses. The structural analyses indicate that the syn‐ and anti‐TBBT‐8 isomers self‐organize into completely different packing arrangements, in the form of solution‐crystallized microribbons and thin films. The resulting charge‐transport properties are strongly dependent on the syn/anti thiophene configurations. Remarkably, solution‐processed OFETs using the syn‐TBBT‐8 isomer show high hole mobilities of up to 10.1 cm2 V−1 s−1, which are more than one order of magnitude higher than those of the anti‐TBBT‐8 isomer. This work highlights the importance of the regioisomeric molecular configuration of thienoacene‐based organic semiconductors for developing high‐performance electronic devices.
Zone‐Annealing‐Assisted Solvent‐Free Processing of Complementary Semiconducting Polymer Blends for Organic Field‐Effect Transistors
Authors: Xue Guobiao , Zhao Yan , Zhao Xikang , Li Hanying , Mei Jianguo 
Published: December 2017

AbstractSemiconducting polymer thin films, which are usually formed by solution‐casting from their organic solutions, are critical in the development of flexible and printed electronics. To seek out a method that can further improve the electrical properties of semiconducting polymers and also be industrially applicable is of vital significance. In this study, the impact of zone annealing on the charge‐transport properties of diketopyrrolopyrrole‐based complementary semiconducting polymer blends in field‐effect transistor devices is investigated. An average mobility increased from 0.66 to 0.87 cm2 V−1 s−1, with a highest of 1.6 cm2 V−1 s−1, is observed. It is also demonstrated that zone annealing can be integrated with melt processing to realize a solvent‐free process for polymer thin films for organic field‐effect transistors (OFETs) and achieve improved charge transport characteristics with a record mobility of 0.54 cm2 V−1 s−1 among melt‐processed OFETs. This work provides an alternative, green, and sustainable processing method to advance polymer‐based organic electronics.
Fullerene‐Based Materials for Photovoltaic Applications: Toward Efficient, Hysteresis‐Free, and Stable Perovskite Solar Cells
Authors: Deng Lin‐Long , Xie Su‐Yuan , Gao Feng 
Published: December 2017

AbstractPerovskite solar cells are promising candidates for next‐generation photovoltaics. Fullerenes and their derivatives can act as efficient electron transport layers, interfacial modification layers, and trap state passivators in perovskite solar cells, all of which play an important role in increasing efficiency, reducing current hysteresis, and enhancing device stability. Herein, recent progress in the use of fullerenes and their derivatives in perovskite solar cells is reviewed, with a particular emphasis on fullerene chemical structures that affect device performance. Potential fullerene candidates that could further improve device performance and stability are also discussed.
High‐Performance Solar Steam Device with Layered Channels: Artificial Tree with a Reversed Design
Authors: Liu He , Chen Chaoji , Chen Guang , Kuang Yudi , Zhao Xinpeng , Song Jianwei , Jia Chao , Xu Xu , Hitz Emily , Xie Hua , Wang Sha , Jiang Feng , Li Tian , Li Yiju , Gong Amy , Yang Ronggui , Das Siddhartha , Hu Liangbing 
Published: December 2017

AbstractSolar steam generation, combining the most abundant resources of solar energy and unpurified water, has been regarded as one of the most promising techniques for water purification. Here, an artificial tree with a reverse‐tree design is demonstrated as a cost‐effective, scalable yet highly efficient steam‐generation device. The reverse‐tree design implies that the wood is placed on the water with the tree‐growth direction parallel to the water surface; accordingly, water is transported in a direction perpendicular to what occurs in natural tree. The artificial tree is fabricated by cutting the natural tree along the longitudinal direction followed by surface carbonization (called as C‐L‐Wood). The nature‐made 3D interconnected micro‐/nanochannels enable efficient water transpiration, while the layered channels block the heat effectively. A much lower thermal conductivity (0.11 W m−1 K−1) thus can be achieved, only 1/3 of that of the horizontally cut wood. Meanwhile, the carbonized surface can absorb almost all the incident light. The simultaneous optimizations of water transpiration, thermal management, and light absorption results in a high efficiency of 89% at 10 kW m−2, among the highest values in literature. Such wood‐based high‐performance, cost‐effective, scalable steam‐generation device can provide an attractive solution to the pressing global clean water shortage problem.
Bimetallic Zeolitic Imidazolite Framework Derived Carbon Nanotubes Embedded with Co Nanoparticles for Efficient Bifunctional Oxygen Electrocatalyst
Authors: Li Yinle , Jia Baoming , Fan Yanzhong , Zhu Kelong , Li Guangqin , Su Cheng‐Yong 
Published: December 2017

AbstractBifunctional oxygen catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with high activities and low‐cost are of prime importance and challenging in the development of fuel cells and rechargeable metal–air batteries. This study reports a porous carbon nanomaterial loaded with cobalt nanoparticles (Co@NC‐x/y) derived from pyrolysis of a Co/Zn bimetallic zeolitic imidazolite framework, which exhibits incredibly high activity as bifunctional oxygen catalysts. For instance, the optimal catalyst of Co@NC‐3/1 has the interconnected framework structure between porous carbon and embedded carbon nanotubes, which shows the superb ORR activity with onset potential of ≈1.15 V and half‐wave potential of ≈0.93 V. Moreover, it presents high OER activity that can be further enhanced to over commercial RuO2 by P‐doped with overpotentials of 1.57 V versus reversible hydrogen electrode at 10 mA cm−2 and long‐term stability for 2000 circles and a Tafel slope of 85 mV dec−1. Significantly, the nanomaterial demonstrates better catalytic performance and durability than Pt/C for ORR and commercial RuO2 and IrO2 for OER. These findings suggest the importance of a synergistic effect of graphitic carbon, nanotubes, exposed Co–Nx active sites, and interconnected framework structure of various carbons for bifunctional oxygen electrocatalysts.