- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Fabrication of Uniaxially Aligned Silica Nanogrooves with Sub-5 nm Periodicity on Centimeter-Scale Si Substrate Using Poly(dimethylsiloxane) Stamp
摘要： The large-area fabrication of aligned nanopatterns with sub-5 nm feature size is crucial for developing nanodevices. Highly ordered nanostructures fabricated through molecular self-assembly exhibit substantial potential for sub-5 nm patterning techniques. Previously, we had reported the fabrication of silica nanogrooves with sub-5 nm periodicity on a Si substrate by using the outermost surfaces of cylindrical surfactant micelles as a template. However, uniaxial alignment of nanogrooves on the entire substrate surface has not yet been achieved. In this study, uniaxially aligned silica nanogrooves were prepared on the entire surface of a Si substrate (2 × 2 cm) by utilizing a poly(dimethylsiloxane) (PDMS) stamp with a striped pattern. The PDMS stamp was placed on the surface of a surfactant thin film precoated on the substrate, although the stamp was not in direct contact with the substrate as in the case of the soft nanoimprint technique. The substrate was then exposed to water vapor, during which cylindrical micelles were aligned in the direction of the guide. Subsequently, by exposing the substrate to an NH3–water vapor mixture, the outermost surfaces of the aligned micelles facing the substrate were replicated with soluble silicate species. The formation of uniaxially aligned nanogrooves on the entire surface of the centimeter-scale substrate was verified by scanning electron microscopy observations and grazing-incidence small-angle X-ray scattering analysis. Thus, herein we provide a simple large-area fabrication method for uniaxially aligned nanopattern with ultra-fine pitch.
关键词： nanoimprint,nanopatterning,alignment control,directed self-assembly,liquid crystals
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Conference on Antenna Measurements & Applications (CAMA) - Va?ster?s (2018.9.3-2018.9.6)] 2018 IEEE Conference on Antenna Measurements & Applications (CAMA) - Guidelines for Millimeter-Wave Antenna Measurements
摘要： The characterization of physically small antennas in the millimeter-wave range has proven to be a challenge. Several research groups have developed new antenna measurement systems to be able to characterize millimeter-wave antennas. These measurement systems mainly focus on the establishment of a well-defined connection between test equipment and the antenna-under-test (AUT) for radiation pattern measurements. However, uncertainties affecting the measurement results are not always well understood. We have investigated the effect of misalignment, the effectiveness of an anechoic environment for frequencies up to 90 GHz and the impact of spurious radiation of the probe.
关键词： anechoic environment,probe radiation,60 GHz,probe connection,uncertainty analysis,alignment,Millimeter wave,antenna measurement
更新于2025-09-23 15:23:52
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Patterning Smectic Liquid Crystals for OFETs at Low Temperature
摘要： The preparation of regular microstructures with liquid crystalline materials for organic field effect transistors (OFETs) is an attractive but challenging issue. However, it is usually limited by the difficulty of forming large-area single crystals aligned in a desirable direction. Herein, several terthiophene (TTP) smectic liquid crystals such as 8-TTP-8 and 12-TTP-11OH are patterned into highly crystalline microstripes by a sandwich system through a dewetting method. Morphology and orientation of the microstripes strongly depend on preparation temperature. Microstripes prepared below crystalline temperature are uniform, well-ordered, and show high field effect transistor (FET) mobility. Meanwhile, π–π stacking direction of the TTP backbone is perpendicular to the microstripe and the molecules stack in layer structure, standing up on the SiO2/Si substrate, which would provide an effective pathway for p-type charge transport. However, higher preparation temperatures at liquid crystalline or isotropic liquid range induce many defects in the crystal formation process and cause incline of the unit cell, thus leading to a sharp decrease in FET mobility. A possible mechanism of molecular stacking at different temperature range is proposed. This strategy promised to provide a new opportunity for the high cost-efficiency fabrication of OFETs.
关键词： OFETs,smectic liquid crystals,terthiophene,alignment,patterning
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE CPMT Symposium Japan (ICSJ) - Kyoto, Japan (2018.11.19-2018.11.21)] 2018 IEEE CPMT Symposium Japan (ICSJ) - Study on corundum-structured p-type iridium oxide thin films and band alignment at iridium oxide /gallium oxide hetero-junction
摘要： Corundum-structured iridium oxide, showing p-type conductivity, is a powerful candidate material for forming high-quality pn hetero-junctions with gallium oxide. We have succeeded in fabricating corundum-structured iridium oxide thin films on sapphire substrates. According to the optical transmittance measurement, the optical bandgap of iridium oxide was found to be approximately 3.0 eV. Furthermore, the band alignment at the iridium oxide /gallium oxide interface was investigated by X-ray photoemission spectroscopy, revealing a staggered-gap (type-Ⅱ) with the valence and conduction band offsets of 3.3 eV and 1.0 eV, respectively.
关键词： p-type oxide semiconductor,band alignment,gallium oxide
更新于2025-09-23 15:22:29
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Robust Hyperspectral Image Domain Adaptation With Noisy Labels
摘要： In hyperspectral image (HSI) classification, domain adaptation (DA) methods have been proved effective to address unsatisfactory classification results caused by the distribution difference between training (i.e., source domain) and testing (i.e., target domain) pixels. However, these methods rely on accurate labels in source domain, and seldom consider the performance drop resulted by noisy label, which often happens since labeling pixel in HSI is a challenging task. To improve the robustness of DA method to label noise, we propose a new unsupervised HSI DA method, which is constructed from both feature-level and classifier-level. First, a linear transformation function is learned in feature-level to align the source (domain) subspace with the target (domain) subspace. Then, a robust low-rank representation based classifier is developed to well cope with the features obtained from the aligned subspace. Since both subspace alignment and the classifier are immune to noisy labels, the proposed method obtains good classification results when confronting with noisy labels in source domain. Experimental results on two DA benchmarks demonstrate the effectiveness of the proposed method.
关键词： low-rank representation,hyperspectral image (HSI) classification,Domain adaptation,subspace alignment
更新于2025-09-23 15:22:29
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Dynamic operation of liquid crystal cell with inherently nanogroove-featured aligned carbon nanotube sheets
摘要： The use of a highly aligned carbon nanotube (CNT) sheet as a multifunctional constituent for liquid crystal (LC) displays and electro-optic LC applications is assessed. The CNT sheet can perform a dual function: one is an alignment layer for LCs, replacing the commonly used rubbed polyimide film, and the other is a transparent conductive layer, taking the place of indium tin oxide. The hydrophobic treatment improved the adhesion quality between aligned CNT bundles and the glass substrate, which helps to preserve the inherently aligned nanogroove morphology of transparent CNT sheets. The test LC display cells, comprising 4-cyano-4′-pentylbiphenyl molecules sandwiched between CNT-sheet-on-glass substrates, demonstrate the operation characteristics comparable to that of the conventional cell under temperature variation and ac electric field of 1 kHz. The results offer a possibility of deploying multifunctional CNT-sheet alignment layers in LC-based devices, especially in the future flexible display applications.
关键词： Indium-tin oxide transparent conductor,Aligned carbon nanotube sheets,Liquid crystal cells,Polyimide alignment layer for liquid crystal display
更新于2025-09-23 15:22:29
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Microscopic-Stress-Induced Retardation between amorphous silicon nitride and amorphous indium zinc oxide having different stresses
摘要： It is very important to increase the contrast ratio in liquid crystal display (LCD) TV using polymer-stabilized vertical alignment (PS-VA) mode. The luminance of the black state is greatly reduced by changing the parameters of the polarizer, the color filter, and the liquid crystal. However, these have the side effect of reducing the characteristics such as the transmittance, the response time, and the viewing angle. In this paper, the luminance of the black state can be reduced by lowering the stress induced retardation at the edge of pixel electrode without changing the materials in the PS-VA mode. It has been shown for the first time that the stress difference in the heterogeneous layers such as amorphous indium zinc oxide (a-IZO) and amorphous silicon nitride (a-SiNx) can optically create birefringence in the microscopic region. By controlling the stress difference in the heterogeneous membrane, the microscopic-stress-induced retardation (MSIR) could be lowered and the contrast ratio of the PS-VA mode could be increased up to 10%.
关键词： stress,birefringence,polymer-stabilized vertical alignment mode,retardation
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 15th International Conference on Group IV Photonics (GFP) - Cancun (2018.8.29-2018.8.31)] 2018 IEEE 15th International Conference on Group IV Photonics (GFP) - Novel Fiber Alignment Method for On-Wafer Testing of Silicon Photonic Devices with PN Junction Embedded Grating Couplers
摘要： We propose a new fiber alignment method using a PN junction embedded grating coupler (GC). It enables us to quickly and easily search the optimum position for optical coupling between the GC and an optical fiber, enabling efficient on-wafer testing.
关键词： fiber alignment,on-wafer testing,photodiode,grating coupler
更新于2025-09-23 15:22:29
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Weighted Manifold Alignment using Wave Kernel Signatures for Aligning Medical image Datasets
摘要： Manifold alignment (MA) is a technique to map many high-dimensional datasets to one shared low-dimensional space. Here we develop a pipeline for using MA to reconstruct high-resolution medical images. We present two key contributions. Firstly, we develop a novel MA scheme in which each high-dimensional dataset can be differently weighted preventing noisier or less informative data from corrupting the aligned embedding. We find that this generalisation improves performance in our experiments in both supervised and unsupervised MA problems. Secondly, we use the wave kernel signature as a graph descriptor for the unsupervised MA case finding that it significantly outperforms the current state-of-the-art methods and provides higher quality reconstructed magnetic resonance volumes than existing methods.
关键词： Slice stacking,Wave kernel signature,Magnetic resonance imaging,Manifold alignment,Graph descriptor
更新于2025-09-23 15:22:29
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[IEEE 2018 5th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace) - Rome, Italy (2018.6.20-2018.6.22)] 2018 5th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace) - Alignment Verification of a Star Tracker Cluster and a Space Telescope for Land-survey Satellite
摘要： For high pointing accuracy space telescope it is necessary to provide the precise determination of relative angular position for the telescope and star sensors. For solving this problem, methods developed are presented which based on onboard discrete ?ltering of measurements, approximation and spline interpolation. We represent accuracy estimates obtained by computer simulation for the alignment veri?cation of the star sensors and telescope onboard a land-survey satellite.
关键词： land-survey telescope,alignment veri?cation
更新于2025-09-23 15:21:21