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91.
Monomeric gold (Au) and silver (Ag) nanoparticle (NP) arrays are self‐assembled uniformly into anodized aluminium oxide (AAO) nanopores with a high homogeneity of greater than 95%, using ultrasonication. The monomeric metal NP array exhibits asymmetric plasmonic absorption due to Fano‐like resonance as interpreted by finite‐difference time‐domain (FDTD) simulation for the numbers up to 127 AuNPs. To examine gap distance‐dependent collective‐plasmonic resonance, the different dimensions of S, M, and L arrays of the AuNP diameters/the gap distances of ≈36 nm/≈66 nm, ≈45 nm/≈56 nm, and ≈77 nm/≈12 nm, respectively, are prepared. Metal NP arrays with an invariable nanogap of ≈50 nm can provide consistent surface‐enhanced Raman scattering (SERS) intensities for Rhodamine 6G (Rh6G) with a relative standard deviation (RSD) of 3.8–5.4%. Monomeric arrays can provide an effective platform for 2D hot‐electron excitation, as evidenced by the SERS peak‐changes of 4‐nitrobenzenethiol (4‐NBT) adsorbed on AgNP arrays with a power density of ≈0.25 mW µm‐2 at 514 and 633 nm. For practical purposes, the bacteria captured by 4‐mercaptophenylboronic acid are found to be easily destroyed under visible laser excitation at 514 nm with a power density of ≈14 mW µm‐2 for 60 min using Ag due to efficient plasmonic‐electron transfer. 相似文献
92.
Van‐Tien Bui Qitao Zhou Jong‐Nam Kim Jung‐Hwan Oh Kwan‐Woo Han Ho‐Suk Choi Sang‐Woo Kim Il‐Kwon Oh 《Advanced functional materials》2019,29(28)
Inspired by treefrog's toe pads that show superior frictional properties, herein, an industrially compatible approach is reported to make an efficient dielectric tribosurface design using customizable nonclose‐packed microbead arrays, mimicking the friction pads of treefrogs, in order to significantly enhance electrification performance and reliability of triboelectric nanogenerator (TENG). The approach involves using an engineering polymer to prepare a highly ordered large‐area concave film, and subsequently the molding of a convex patterned triboreplica in which the concave film is exploited as a reusable master mold. A nature‐inspired TENG based on the patterned polydimethylsiloxane (PDMS) paired with flat aluminum (Al) can generate a relatively high power density of 8.1 W m?2 even if a very small force of ≈6.5 N is applied. Moreover, the convex patterned PDMS‐based TENG possesses exceptional durability and reliability over 25 000 cycles of contact–separation. Considering the significant improvements in power generation of TENG; particularly at very small force, together with cost‐effectiveness and possibility of mass production, the present methodology may pave the way for large‐scale blue energy harvesting and commercialization of TENGs for many practical applications. 相似文献
93.
Q. V. Bui N. D. Nam J. W. Yoon D. H. Choi A. Kar J. G. Kim S. B. Jung 《Journal of Electronic Materials》2011,40(9):1937-1942
The performance of surface finishes as a function of the pH of the utilized plating solution was evaluated by electrochemical
impedance spectroscopy (EIS) and potentiodynamic polarization tests in 3.5 wt.% NaCl solution. In addition, the surface finishes
were examined by x-ray diffraction (XRD), and the contact angle of the liquid/solid interface was recorded. NiP films on copper
substrates with gold coatings exhibited their highest coating performance at pH 5. This was attributed to the films having
the highest protective efficiency and charge transfer resistance, lowest porosity value, and highest contact angle among those
examined as a result of the strongly preferred Au(111) orientation and the improved surface wettability. 相似文献
94.
Nguyen Ba Cao Tran Xuan Nam Hoang Tran Manh Dung Le The 《Mobile Networks and Applications》2020,25(1):363-372
Mobile Networks and Applications - In this paper, we study the performance of a full-duplex (FD) relay system in vehicle-to-vehicle (V2V) communication. In this relay communication system, the... 相似文献
95.
Myung‐Yeon Cho Sunghoon Kim Ik‐Soo Kim Eun‐Seong Kim Zhi‐Ji Wang Nam‐Young Kim Sang‐Wook Kim Jong‐Min Oh 《Advanced functional materials》2020,30(3)
A new capacitive‐type humidity sensor is proposed using novel materials and fabrication process for practical applications in sensitive environments and cost‐effective functional devices that require ultrasensing performances. Metal halide perovskites (CsPbBr3 and CsPb2Br5) combined with diverse ceramics (Al2O3, TiO2, and BaTiO3) are selected as sensing materials for the first time, and nanocomposite powders are deposited by aerosol deposition (AD) process. A state‐of‐the‐art CsPb2Br5/BaTiO3 nanocomposite humidity sensor prepared by AD process exhibits a significant increase in humidity sensing compared with CsPbBr3/Al2O3 and CsPbBr3/TiO2 sensors. An outstanding humidity sensitivity (21426 pF RH%?1) with superior linearity (0.991), fast response/recovery time (5 s), low hysteresis of 1.7%, and excellent stability in a wide range of relative humidity is obtained owing to a highly porous structure, effective charge separation, and water‐resistant characteristics of CsPb2Br5. Notably, this unprecedented result is obtained via a simple one‐step AD process within a few minutes at room temperature without any auxiliary treatment. The synergetic combination of AD technique and perovskite‐based nanocomposite can be potentially applied toward the development of multifunctional sensing devices. 相似文献
96.
This paper describes an ultra‐wideband (UWB) antenna that uses a ring resonator concept. The proposed antenna can operate in the entire UWB, and the IEEE 802.11a frequency band can be rejected by inserting a notch stub into the ring resonator. The experiment results indicate that the measured impedance bandwidth of the proposed antenna is 17.5 GHz (2.5 GHz to at least 20 GHz). The proposed UWB antenna has omnidirectional radiation patterns with a gain variation of 3 dBi (1 dBi to 4 dBi). 相似文献
97.
Through‐silicon via (TSV) technology provides much of the benefits seen in advanced packaging, such as threedimensional integrated circuits and 3D packaging, with shorter interconnection paths for homo‐ and heterogeneous device integration. In TSV, a destructive cross‐sectional analysis of an image from a scanning electron microscope is the most frequently used method for quality control purposes. We propose a quantitative evaluation method for TSV etch profiles whereby we consider sidewall angle, curvature profile, undercut, and scallop. A weighted sum of the four evaluated parameters, nominally total score (TS), is suggested for the numerical evaluation of an individual TSV profile. Uniformity, defined by the ratio of the standard deviation and average of the parameters that comprise TS, is suggested for the evaluation of wafer‐to‐wafer variation in volume manufacturing. 相似文献
98.
Raghavendra C. Mundargi Michael G. Potroz Soohyun Park Jae Hyeon Park Hitomi Shirahama Jae Ho Lee Jeongeun Seo Nam‐Joon Cho 《Advanced functional materials》2016,26(4):487-497
Herein, the exploration of natural plant‐based “spores” for the encapsulation of macromolecules as a drug delivery platform is reported. Benefits of encapsulation with natural “spores” include highly uniform size distribution and materials encapsulation by relatively economical and simple versatile methods. The natural spores possess unique micromeritic properties and an inner cavity for significant macromolecule loading with retention of therapeutic spore constituents. In addition, these natural spores can be used as advanced materials to encapsulate a wide variety of pharmaceutical drugs, chemicals, cosmetics, and food supplements. Here, for the first time a strategy to utilize natural spores as advanced materials is developed to encapsulate macromolecules by three different microencapsulation techniques including passive, compression, and vacuum loading. The natural spore formulations developed by these techniques are extensively characterized with respect to size uniformity, shape, encapsulation efficiency, and localization of macromolecules in the spores. In vitro release profiles of developed spore formulations in simulated gastric and intestinal fluids have also been studied, and alginate coatings to tune the release profile using vacuum‐loaded spores have been explored. These results provide the basis for further exploration into the encapsulation of a wide range of therapeutic molecules in natural plant spores. 相似文献
99.
Ki Dong Yang Yoonhoo Ha Uk Sim Junghyun An Chan Woo Lee Kyoungsuk Jin Younghye Kim Jimin Park Jung Sug Hong Jun Ho Lee Hye‐Eun Lee Hui‐Yun Jeong Hyungjun Kim Ki Tae Nam 《Advanced functional materials》2016,26(2):233-242
The reduction of carbon dioxide (CO2) into chemical feedstock is drawing increasing attention as a prominent method of recycling atmospheric CO2. Although many studies have been devoted in designing an efficient catalyst for CO2 conversion with noble metals, low selectivity and high energy input still remain major hurdles. One possible solution is to use the combination of an earth‐abundant electrocatalyst with a photoelectrode powered by solar energy. Herein, for the first time, a p‐type silicon nanowire with nitrogen‐doped graphene quantum sheets (N‐GQSs) as heterogeneous electrocatalyst for selective CO production is demonstrated. The photoreduction of CO2 into CO is achieved at a potential of ?1.53 V versus Ag/Ag+, providing 0.15 mA cm?2 of current density, which is 130 mV higher than that of a p‐type Si nanowire decorated with well‐known Cu catalyst. The faradaic efficiency for CO is 95%, demonstrating significantly improved selectivity compared with that of bare planar Si. The density functional theory (DFT) calculations are performed, which suggest that pyridinic N acts as the active site and band alignment can be achieved for N‐GQSs larger than 3 nm. The demonstrated high efficiency of the catalytic system provides new insights for the development of nonprecious, environmentally benign CO2 utilization. 相似文献
100.
Indoline‐Based Molecular Engineering for Optimizing the Performance of Photoactive Thin Films 下载免费PDF全文
Ming Yu Jin Byung‐Man Kim Hyun Sil Jung Jun‐Hyeok Park Deok‐Ho Roh Dong Guk Nam Tae‐Hyuk Kwon Do Hyun Ryu 《Advanced functional materials》2016,26(38):6876-6887
New indoline dyes ( RK‐1 – 4 ) were designed with a planar geometry and high molar extinction coefficient, which provided surprising power conversion efficiency (PCE) with a thin titanium dioxide film in dye‐sensitized solar cells (DSCs). They had a difference in only alkyl chain length. Despite the same molecular structure, the performance of the respective DSCs varied significantly. Investigating the dye adsorption processes and charge transfer kinetics, the alkyl chain length was determined to affect the dye surface coverage as well as the recombination between the injected photoelectrons and the oxidized redox mediators. When applied to the DSCs as a light harvester, RK‐3 with the dodecyl group exhibited the best photocurrent density, consequently achieving the best PCE of 9.1% with a 1.8 μm active and 2.5 μm scattering layer because of the most favorable charge injection. However, when increasing the active layer thickness, overall device performance deteriorated and the charge collection and regeneration played major roles for determining the PCE. Therefore, RK‐2 featuring the highest surface coverage and moderate alkyl chain length obtained the highest PCEs of 8.8% and 7.9% with 3.5 and 5.1 μm active layers, respectively. These results present a promising perspective of organic dye design for thin film DSCs. 相似文献