bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metallopolymer Organohydrogels with Photo‐Controlled Coordination Crosslinks Work Properly Below 0 °C
Authors: Liu Jiahui , Xie Chaoming , Kretzschmann Annika , Koynov Kaloian , Butt Hans‐Jürgen , Wu Si 
Published: February 2020

AbstractControlling the structures and functions of gels is important for both fundamental research and technological applications. Introducing photoresponsive units into gels enables remote control of their properties with light. However, existing gels show photoresponsiveness only at room temperature or elevated temperatures. The development of photoresponsive gels that work below 0 °C can expand their usage in cold environments. Here, photoresponsive metallopolymer organohydrogels that function even at −20 °C are reported. The organohydrogels are prepared using photoresponsive Ru–thioether coordination bonds as reversible crosslinks to form polymer networks. A water/glycerol mixture is used as an anti‐freezing solvent. At −20 °C, the Ru–thioether coordination bonds are dissociated under light irradiation and reformed reversibly in the dark, which result in alternating crosslinking densities in the polymer networks. This process enables inducing reversible gel‐to‐sol transitions, healing damaged gels, controlling the mechanical properties and volumes of the gels, and rewriting microstructures on the gels below 0 °C.
Semiconducting Metal Oxide Photonic Crystal Plasmonic Photocatalysts
Authors: Collins Gillian , Lonergan Alex , McNulty David , Glynn Colm , Buckley Darragh , Hu Changyu , O'Dwyer Colm 
Published: February 2020

AbstractPlasmonic photocatalysis has facilitated rapid progress in enhancing photocatalytic efficiency under visible light irradiation. Poor visible‐light‐responsive photocatalytic materials and low photocatalytic efficiency remain major challenges. Plasmonic metal–semiconductor heterostructures where both the metal and semiconductor are photosensitive are promising for light harvesting catalysis, as both components can absorb solar light. Efficiency of photon capture can be further improved by structuring the catalyst as a photonic crystal. Here, the synthesis of photonic crystal plasmonic photocatalyst materials using Au nanoparticle‐functionalized inverse opal (IO) photonic crystals is reported. A catalyst prepared using a visible‐light‐responsive semiconductor (V2O5) displayed over an order of magnitude increase in reaction rate under green light excitation (λ = 532 nm) compared to no illumination. The superior performance of Au‐V2O5 IO is attributed to spectral overlap of the electronic bandgap, localized surface plasmon resonance, and incident light source. For the Au‐TiO2 catalyst, despite coupling of the LSPR and excitation source at λ = 532 nm, this is not as effective in enhancing photocatalytic activity compared to carrying out the reaction under broadband visible light, which is attributed to improved photon adsorption in the visible by the presence of a photonic bandgap, and exploiting slow light in the photonic crystal to enhance photon absorption to create this synergistic type of photocatalyst.
Integrating Effect of Surface Modification of Microporous Carbon by Phosphorus/Oxygen as well as the Redox Additive of p‐Aminophenol for High‐Performance Supercapacitors
Authors: Tang Qianfang , Zhong Min , Liu Hao , Chen Xiangying , Zhang Zhongjie , Chen Shuanghong 
Published: February 2020

AbstractIn present work, commercial microporous carbon materials are modified on the surface with phosphorus/oxygen species by using phytic acid as sole dopant, which plays crucial effect on the carbon structure, wettability, electrical conductivity, and capacitive behaviors. It reveals that with increasing the content of heteroatoms, the porosity and contact angle are decreased but the conductivity turns much larger. Furthermore, p‐aminophenol is introduced to serve as redox additive, which can produce more active surface sites by forming hydrogen bond and complexation with the surface functional groups, further providing additional pseudo‐capacitance. As a result, the energy density of carbon sample by phosphorus/oxygen doping in 1 m H2SO4 electrolyte with p‐aminophenol is as high as 9.2 Wh kg−1, which is 2.6 than that of pristine carbon. What is more, in terms of the simple operation and effective performance, the integration of surface modification toward carbon materials and redox additive can be favorable for largely enhancing the supercapacitor performance.
Direct Integration of Few‐Layer MoS2 at Plasmonic Au Nanostructure by Substrate‐Diffusion Delivered Mo
Authors: Ma Rui , Haastrup Mark J. , Wang Zegao , Liu Yumin , Ye Han , Dong Mingdong , Lauritsen Jeppe V. , Sutherland Duncan S. 
Published: February 2020

AbstractThe seamless combination of plasmonic structures with metal oxides and in particular with 2D materials has attracted significant recent interests. Here, a novel approach to grow molybdenum disulfide (MoS2) is presented: an optically active 2D material, directly onto plasmonic nanoscale gold disks via a surface diffusion delivery of Mo from within the nanostructure and a sulfidation process. X‐ray photoelectron spectroscopy and Raman spectroscopy measurements demonstrate the existence and the reaction process of few layered MoS2. Delivery of Mo from within the nanostructure and direct growth of MoS2 has the potential to form better defined metal/MoS2 interfaces compared to exfoliation routes. This facile approach has the potential for application in photodetector or other devices.
A Skin‐Inspired, Interactive, and Flexible Optoelectronic Device with Hydrated Melanin Nanoparticles in a Protein Hydrogel–Elastomer Hybrid
Authors: Gogurla Narendar , Roy Biswajit , Min Kyungtaek , Park Ji‐Yong , Kim Sunghwan 
Published: February 2020

AbstractMelanin, a biologically occurring pigment featuring broadband optical absorption, ion‐binding affinity including antioxidative and radical‐scavenging properties, and hydration‐dependent electrical conductivity is an ideal natural semiconducting material for interfacing electronics with biological systems. Here, a skin‐mimicking optoelectronic device with a melanin nanoparticle (MNP) dispersion in a protein hydrogel–elastomer hybrid (a mimic of epidermis/dermis layers with melanin) and its application as a dopamine sensor and a UV index meter are reported. MNPs dispersed in water are placed in the elastomer reservoir with integrated silver nanowire electrodes and a transparent silk hydrogel window cover; they exhibit n‐type semiconducting behavior with increased conductivities compared with those of dehydrated MNPs. Enhanced generation of free radicals by light illumination results in an increase of the electrical conductivity. In addition, the artificial optoelectronic skin interacts with its environment through the silk hydrogel window. Applications of the device, including its use as a dopamine sensor and a UV index meter to detect dopamine and UV light passing through the window, are demonstrated. The sensitivity of the dopamine sensor is enhanced by the light illumination.
A Large‐Area, Stretchable, Textile‐Based Tactile Sensor
Authors: Zhang Youzhi , Lin Zhengkang , Huang Xingping , You Xiaojun , Ye Jinhua , Wu Haibin 
Published: February 2020

AbstractA tactile sensor is a necessary means for intelligent equipment to acquire external environment information and improve the performance of human–robot interaction. Although high‐performance tactile sensor array is widely studied, the large number of wires required to transmit data from numerous arrays is still a major obstacle in large‐area application. In this study, a large‐area, low‐cost, stretchable, textile‐based tactile sensor, which is sensitive for contact position, is proposed. The sensor has a simple three‐layer structure and four external wires due to the use of a novel double‐faced effect functional knitted textile with “self‐uniformity” characteristic. The porous polyurethane foam with a large pore size is first reported as touch switch material. It not only has excellent touch switch function, but also makes the sensor have a soft and elastic touch and good impact buffering. In addition, the application of radial basis function neural network makes the sensor have self‐learning “intelligence,” which makes the sensor flexibly and quickly arrange even on the surface of a complex 3D object. Finally, the potential applications of the sensor are demonstrated. This study shows that the sensor has great potential in the fields of wearable devices, robot interaction control, and human–computer interface.
Synergistic Resistance Modulation toward Ultrahighly Sensitive Piezoresistive Pressure Sensors
Authors: Yuan Liqian , Wang Zhongwu , Li Hongwei , Huang Yinan , Wang Shuguang , Gong Xue , Tan Ziting , Hu Yongxu , Chen Xiaosong , Li Jie , Lin Hongzhen , Li Liqiang , Hu Wenping 
Published: February 2020

AbstractImprovement of sensitivity of electrical piezoresistive sensors is critical for high‐precision and ultrasensitive detection, which mainly depends on the modulation ability of total resistance of sensor under applied pressure. However, in most of the reported sensor devices, the contact resistance and body resistance (the key parts of total resistance of sensor) generally cannot be modulated simultaneously, which results in the limited sensitivity. In this work, an ultrahighly sensitive piezoresistive pressure sensor with an exquisitely designed structure is demonstrated, providing an uncomparable advantage of synergistic modulation of contact resistance and body resistance under applied pressure. As a result, the sensor shows excellent sensing performance, with the highest sensitivity up to 11 668.6 kPa−1, the detection limit as low as 0.425 Pa, and the great stability over 20 000 cycle measurements. In respect of practical application, the high sensitivity endows the sensor with high‐precision recognition ability for detecting the weak pressure signals such as sound wave of ringtone and fluctuation of breath or pulse. These results suggest the synergistic resistance modulation to be an effective method toward piezoresistive pressure sensors with ultrahigh sensitivity and offer a new strategy for the achievement of high‐performance pressure sensors.
Development of a High‐Performance Handheld Triboelectric Nanogenerator with a Lightweight Power Transmission Unit
Authors: Choi Seonbeen , Cho Sumin , Yun Yeongcheol , Jang Sunmin , Choi Jun Hyuk , Ra Yoonsang , La Moonwoo , Park Sung Jea , Choi Dongwhi 
Published: February 2020

AbstractA triboelectric nanogenerator (TENG) is a promising energy harvester that exploits the combination of contact electrification between two different material surfaces and electrical induction. In this study, a handheld‐TENG (HH‐TENG) is developed to harvest biomechanical energy effectively, especially energy generated from finger motions, which is one of the most common body movements involving lots of energy. To enhance the electrical output performance of the device while minimizing the inconvenience caused by carrying it, a rationally designed lightweight power transmission unit is adopted. As a result, an extremely high number of output cycles with high specific peak power (greater than 10 µW g–1) can be achieved in a single operation of the HH‐TENG. Although the proposed HH‐TENG weighs less than 70 g, the developed HH‐TENG can be connected with commercially available electric circuits such as an AC‐DC converter to generate not only reliable and continuous DC voltage to power portable electronics, but also further boosted open‐circuit voltage greater than 2.5 kV, which is sufficient to generate microplasma in a room environment. Adoption of a lightweight power transmission unit with the TENG can be considered as an effective strategy to significantly enhance the specific power, which advances the TENG toward practical implementation.
Pick and Place Distributed Feedback Lasers Using Organic Single Crystals
Authors: Ma Suqian , Wei Mengjie , Rajendran Sai Kiran , Karl Markus , Xu Bin , Gather Malte C. , Tian Wenjing , Turnbull Graham A. , Samuel Ifor D. W. 
Published: February 2020

AbstractOrganic single crystals are of interest for optoelectronic applications due to their highly ordered molecular stacking and small defect concentration, giving the possibility of high mobility and luminescence efficiency. To achieve lasing in large flat single crystals, a simple “pick and place” method of mounting organic single crystals onto distributed feedback gratings is demonstrated. Efficient lasing is achieved with three kinds of active organic single crystals, indicating the potential for broad application of the method for making single crystal lasers using distributed feedback gratings. Detailed investigations of the anisotropic refractive index and waveguide simulations further confirm that distributed feedback can provide efficient ways of fabricating organic single crystal lasers.
Boosted UV Photodetection Performance in Chemically Etched Amorphous Ga2O3 Thin‐Film Transistors
Authors: Han Zuyin , Liang Huili , Huo Wenxing , Zhu Xiaoshan , Du Xiaolong , Mei Zengxia 
Published: February 2020

AbstractA three‐terminal thin‐film transistor (TFT) architecture is essential for photodetectors to reach a good balance between high responsivity and fast response speed. Bottom‐gate amorphous Ga2O3 (a‐Ga2O3) TFTs are fabricated to boost their UV photodetection properties. During the device fabrication process, a simple chemical‐etching solution with the advantages of easy operation, low cost, and compatibility with traditional lithography process, is developed to selectively etch a‐Ga2O3 films. The a‐Ga2O3 channel etched device on Si manifests an effective suppression of the commonly observed gate leakage current. Meanwhile, a patterned a‐Ga2O3 TFT on quartz shows an excellent n‐type TFT performance with an on/off ratio as high as ≈107. It is further applied as a phototransistor, to diminish the persistent photoconductivity (PPC) effect while keeping a high responsivity (R) as well. Under the 254 nm UV illumination, the a‐Ga2O3 phototransistor demonstrates a high light‐to‐dark ratio of 5 × 107, a high responsivity of 5.67 × 103 A W−1, and a high detectivity of 1.87 × 1015 Jones. Remarkably, the PPC phenomenon in a‐Ga2O3 UV phototransistors is effectively suppressed by applying a positive gate pulse, which greatly shortens the decay time to 5 ms and offers a‐Ga2O3 possible inroads into imaging applications.
Highly Stable All‐Inorganic Perovskite Quantum Dots Using a ZnX2‐Trioctylphosphine‐Oxide: Application for High‐Performance Full‐Color Light‐Emitting Diode
Authors: Baek Seungmin , Kang Seokwoo , Son Chaeyeon , Shin So Jeong , Kim Jong H. , Park Jongwook , Kim Sang‐Wook 
Published: February 2020

AbstractPerovskite is a very promising material that is being extensively studied at the bulk and nanosize scales because it has outstanding optical properties, including high quantum efficiency and narrow emission spectra. However, perovskite has stability issues related to heat, air, and light. To overcome these, highly stable perovskite quantum dots (PeQDs) are developed using excess Zn precursor and trioctylphosphine‐oxide (TOPO). In particular, it is clarified that Zn and TOPO are combined and these complexes are attached to the surface of the PeQDs through 31P NMR. They not only have high quantum efficiency and sharp full width at half maximum values (15–30 nm) but also have improved long‐term stability at high temperature. Additionally, XPS measurements are conducted for a detailed surface analysis of PeQDs, finding that the TOPO‐Zn complex effectively decrease PbO bonding in the lattice. Perovskite full‐color electroluminescence (EL) devices are fabricated using PeQDs and 9,9‐bis[4‐[(4‐ethenylphenyl)methoxy]phenyl]‐N2,N7‐di‐1‐naphthalenyl‐N2,N7‐diphenyl‐9H‐fluorene‐2,7‐diamine (VB‐FNPD) as a new cross‐linkable hole transporting material. The VB‐FNPD has a high‐hole carrier mobility compared to the PVK as conventional hole‐transporting layer. As a result of EL performance, they have high EQE (%) and current efficiency (Cd A−1) of (7.12%, 9.93 Cd A−1) for red, (6.06%, 32.5 Cd A−1) for green, and (0.56%, 0.88 Cd A−1) for blue‐emitting devices, respectively.
Self‐Powered Humidity Sensor Using Chitosan‐Based Plasmonic Metal–Hydrogel–Metal Filters
Authors: Jang Jaehyuck , Kang Kyungnam , Raeis‐Hosseini Niloufar , Ismukhanova Aizhan , Jeong Heonyeong , Jung Chunghwan , Kim Byeongsu , Lee Jung‐Yong , Park Inkyu , Rho Junsuk 
Published: February 2020

AbstractA tunable Fabry–Pérot resonator is realized using metal–insulator–metal structure, in which the insulator is chitosan hydrogel. The chitosan swells in response to changes in relative humidity; this change affects transmissive structural color of the multilayer structure. This tunable resonator is utilized for a humidity sensor combined with a photovoltaic cell. The change in current through the photovoltaic cell provides rapid precise measurement of relative humidity, and the change in color of the multilayer provides an approximate, remotely‐readable estimate. The response requires no power, so the device has numerous sensing applications.
An Ultraviolet–Visible and Near‐Infrared‐Responded Broadband NIR Phosphor and Its NIR Spectroscopy Application
Authors: Zhou Xufeng , Geng Wanying , Li Junyi , Wang Yichao , Ding Jianyan , Wang Yuhua 
Published: February 2020

AbstractHigh‐radiance near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) are demanded for wearable biosensing devices and the properties of these pc‐LEDs are highly dependent on the performance of the NIR phosphor. An ultraviolet–visible and NIR‐responded broadband NIR NaScGe2O6:Cr3+ phosphor is reported. Under 490 nm excitation, NaScGe2O6:Cr3+ shows broad emission band from 700 to 1250 nm, which covers the first and second NIR windows. An NIR pc‐LED with radiant flux of 12.07 mW@350 mA is realized based on NaScGe2O6:Cr3+ and 450 nm blue LED chip. The ability of high‐power NIR light of the NIR pc‐LED to penetrate human tissues is observed successfully. Additionally, in NaScGe2O6:Cr3+, the luminescence performance of Cr3+ under 808 nm laser excitation is achieved for the first time.
Optical Functional Units in Zero‐Dimensional Metal Halides as a Paradigm of Tunable Photoluminescence and Multicomponent Chromophores
Authors: Li Mingze , Molokeev Maxim S. , Zhao Jing , Xia Zhiguo 
Published: February 2020

AbstractZero‐dimensional (0D) organic–inorganic hybrid luminescent metal halides have many promising optoelectronic applications; however, the single building unit in the 0D framework restricts their multimode optical control and photoluminescence tuning. Thus, it remains urgent but challenging to rationally design distinct anionic polyhedral with different optical functions and further expand this family by an equivalent cation substitution and halogen replacement. Herein, (C9NH20)9[Pb3X11](MX4)2 (X = Br and Cl, M = Mn, Fe, Co, Ni, Cu, and Zn) is successfully synthesized verifying the rationality of the design philosophy, and the optical characterizations demonstrate the effects of X‐position anions and M‐position cations on luminescence process. Intriguingly, both [Pb3X11]5− and [MX4]2− perform as inorganic building units in this 0D system and optically active centers, in which the former leads to high‐efficiency broad‐band yellow/green emission originating from self‐trapped excitons and the as‐observed multicomponent chromophores are derived from the absorption of the latter in the visible light region. The present work highlights the importance of different optical functional units showing synergistic effects on the physical properties and inspires future studies to explore multifunctional application of 0D luminescent metal halides.
Dissolving Microneedles Loading TPGS Biphasic Functionalized PLGA Nanoparticles for Efficient Chemo‐Photothermal Combined Therapy of Melanoma
Authors: Peng Tingting , Huang Yao , Feng Xiaoqian , Zhu Chune , Ma Xiangyu , Wang Xinyi , Bai Xuequn , Pan Xin , Wu Chuanbin 
Published: February 2020

AbstractThe poly (lactic‐co‐glycolic acid) nanoparticle (PLGA NP) has been widely used in the biomedical field. However, it is insensitive to degradation upon laser irradiation, resulting in a limited increase in drug release, which compromises the therapeutic efficacy. To actively promote drug release, the biphasic α‐tocopheryl succinate (TPGS) functionalized PLGA NPs (PTNPs) are developed by introducing TPGS into the aqueous and organic phase to generate pores in the PLGA core during preparation. Paclitaxel and indocyanine green are encapsulated in the PTNPs to realize chemo‐photothermal combined therapy, and PTNPs are delivered through dissolving microneedles (DMNs) for local treatment in melanoma. PTNPs show enhanced drug release and improved cytotoxicity due to their greater ability in inhibiting cell microtubule depolymerization. In vivo tumor suppression investigation and ki‐67 immunohistochemical staining of tumor tissue further show the superiority of PTNPs loaded DMNs against tumor growth, and photothermal therapy synergistically enhances the chemotherapeutic effect of PTNPs. Moreover, the living imaging of mice demonstrates that the drug is successfully retained in the tumor tissue to avoid it entering into the circulation and producing adverse effects. Therefore, the PTNPs loaded DMNs show a favorable prospect in the treatment of superficial tumor.
A New Strategy for Detecting Plant Hormone Ethylene Using Oxide Semiconductor Chemiresistors: Exceptional Gas Selectivity and Response Tailored by Nanoscale Cr2O3 Catalytic Overlayer
Authors: Jeong Seong‐Yong , Moon Young Kook , Kim Tae‐Hyung , Park Sei‐Woong , Kim Ki Beom , Kang Yun Chan , Lee Jong‐Heun 
Published: February 2020

AbstractA highly selective and sensitive detection of the plant hormone ethylene, particularly at low concentrations, is essential for controlling the growth, development, and senescence of plants, as well as for ripening of fruits. However, this remains challenging because of the non‐polarity and low reactivity of ethylene. Herein, a strategy for detecting ethylene at a sub‐ppm‐level is proposed by using oxide semiconductor chemiresistors with a nanoscale oxide catalytic overlayer. The SnO2 sensor coated with the nanoscale catalytic Cr2O3 overlayer exhibits rapid sensing kinetics, good stability, and an unprecedentedly high ethylene selectivity with exceptional gas response (Ra/Rg − 1, where Ra represents the resistance in air and Rg represents the resistance in gas) of 16.8 at an ethylene concentration of 2.5 ppm at 350 °C. The sensing mechanism underlying the ultraselective and highly sensitive ethylene detection in the unique bilayer sensor is systematically investigated with regard to the location, configuration, and thickness of the catalytic Cr2O3 overlayer. The mechanism involves the effective catalytic oxidation of interfering gases into less‐ or non‐reactive species, without limiting the analyte gas transport. The sensor exhibits a promising potential for achieving a precise quantitative assessment of the ripening of five different fruits.