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- 摘要
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- 实验方案
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Resonance Coupling in Heterostructures Composed of Silicon Nanosphere and Monolayer WS <sub/>2</sub> : A Magnetic-Dipole-Mediated Energy Transfer Process
摘要： Light?matter resonance coupling is a long-studied topic for both fundamental research and photonic and optoelectronic applications. Here we investigated the resonance coupling between the magnetic dipole mode of a dielectric nanosphere and 2D excitons in a monolayer semiconductor. By coating an individual silicon nanosphere with a monolayer of WS2, we theoretically demonstrated that, because of the strong energy transfer between the magnetic dipole mode of the nanosphere and the A-exciton in WS2, resonance coupling evidenced by anticrossing behavior in the scattering energy diagram was observed, with a mode splitting of 43 meV. In contrast to plexcitons, which involve plasmonic nanocavities, the resonance coupling in this all-dielectric heterostructure was insensitive to the spacing between the silicon nanosphere core and the WS2 shell. Additionally, the two split modes exhibited distinct light-scattering directionality. We further experimentally demonstrated the resonance coupling effect by depositing silicon nanospheres with different diameters onto a WS2 monolayer and collecting the scattering spectra of the resulting heterostructures under ambient conditions. We further demonstrated active control of the resonance coupling by temperature scanning. Our findings highlighted the potential of our all-dielectric heterostructure as a solid platform for studying strong light?matter interactions at the nanoscale.
关键词： magnetic dipole modes,two-dimensional materials,resonance coupling,two-dimension excitons,silicon nanospheres
更新于2025-09-23 15:23:52
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Electrical contacts to two-dimensional transition-metal dichalcogenides
摘要： Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have attracted enormous interests as the novel channel materials for atomically thin transistors. Despite considerable progress in recent years, the transistor performance is largely limited by the excessive contact resistance at the source/drain interface. In this review, a summary of recent progress on improving electrical contact to TMDC transistors is presented. Several important strategies including topology of contacts, choice of metals and interface engineering are discussed.
关键词： Fin-FET,channel materials,two-dimension
更新于2025-09-23 15:23:52
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Two-Dimensional Compressed Sensing Using Two-Dimensional Random Permutation for Image Encryption-then-Compression Applications
摘要： Block compressed sensing with random permutation (BCS-RP) has been shown to be very effective for image Encryption-then-Compression (ETC) applications. However, in the BCS-RP scheme, the statistical information of the blocks is disclosed, because the encryption is conducted within each small block of the image. To solve this problem, a two-dimension compressed sensing (2DCS) with 2D random permutation (2DRP) strategy for image ETC applications is proposed in this letter, where the 2DRP strategy is used for encrypting the image and the 2DCS scheme is used for compressing the encrypted image. Compared with the BCS-RP scheme, the proposed approach has two benefits. Firstly, it offers better security. Secondly, it obtains a significant gain of peak signal-to-noise ratio (PSNR) of the reconstructed-images.
关键词： image encryption,image compression,two-dimension compressed sensing,Encryption-then-Compression,two-dimension random permutation
更新于2025-09-23 15:22:29
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Hierarchical Core-Shell Structure of 2D VS2@VC@N-Doped Carbon Sheets Decorated by Ultrafine Pd Nanoparticles: Assembled in 3D Rosette-like Array on Carbon Fiber Microelectrode for Electrochemical Sensing
摘要： The development of two-dimension (2D) nanohybrid materials with heterogeneous component in nanoscale and three-dimension (3D) well-ordered assembly in microscale has been regarded as an effective way to improve their overall performances by synergistic coupling of the optimized structure and composition. In this work, we reported the design and synthesis of a new type of hierarchically core-shell structure of 2D VS2@VC@N-doped carbon (NC) sheets decorated by ultrafine Pd nanoparticles (PdNPs), which were vertically grown on carbon fiber (CF) and assembled into a unique 3D rosette-like array. The resultant VS2@VC@NC-PdNPs modified CF microelectrode integrated the structural and electrochemical properties of the heterogeneous hybridization of core-shell VS2@VC@NC-PdNPs sheets with unique rosette-like array structure, and gave rise to a significant improvement in terms of electron transfer ability, electrocatalytic activity, stability and biocompatibility. Under the optimized conditions, the VS2@VC@NC-PdNPs modified CF microelectrode demonstrated excellent electrochemical sensing performance towards biomarker hydrogen peroxide (H2O2) including high sensitivity of 152.7 μA cm-2 mM-1, low detection limit of 50 nM (a signal-to-noise ratio of 3:1), as well as good reproducibility and anti-interference ability, which could be used for real-time in situ electrochemical detection of H2O2 in live cancer cells and cancer tissue. The remarkable performances of the proposed nanohybrid microelectrode will have a profound impact on the design of diverse 2D layered materials as promising candidate for electrochemical biosensing applications.
关键词： electrochemical sensing,hierarchical core-shell structure,three-dimension rosette-like sheets array,Two-dimension layered nanomaterials,cancer biomarker detection
更新于2025-09-23 15:19:57
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Monolayer single crystal two-dimensional quantum dots via ultrathin cutting and exfoliating; è??è?????????????￥?|?????¤?????±????????o???′é???-???1;
摘要： Two-dimensional (2D) atomically thin quantum dots (QDs) possess extraordinary electrical and optical properties. However, fabricating high quality 2D QDs via a universal and reliable technique remains a challenge. Here, we report a simple strategy to prepare high quality, monolayer single crystal 2D QDs via ultrathin cutting 2D bulk single crystals by ultramicrotome, followed by an exfoliation process. The as-prepared 2D QDs have pristine surface, high quality, high monolayer yield and high photoluminescence quantum yield (the highest photoluminescence quantum yield of WS2 is 18%), which can be used as promising, low toxic, biocompatible, and good cell-permeability fluorescent labeling agents for in vitro imaging.
关键词： photoluminescence quantum yield,ultra-thin cutting,single crystal,two-dimension,quantum dots
更新于2025-09-23 15:19:57
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Dynamic proportional-fuzzy grip control for?robot arm by two-dimensional vision sensing method
摘要： In this study, a four-degree of freedom (4-DOF) robot arm uses an innovative two-dimensional vision sensing method to grip a moving target on a moving platform. This study utilizes forward and inverse kinematics to establish a dynamic model of the 4-DOF robot arm. A computer as a controller and a single charge-coupled device (CCD) calculates the two-dimensional vision sensing method and sends commands to an Arduino Uno microcontroller to drive the robot arm. According to simulation results of transient and steady states in MATLAB SimMechanics, the response of the dynamic proportional-fuzzy controller is better than the response of proportional–integral–derivative controller. To demonstrate a precise control of the point-contact grip, this study utilizes a ping pong ball as a target on a moving platform. Using the dynamic proportional-fuzzy controller based on the two-dimensional vision sensing method, the 4-DOF robot arm can position, grip, and carry a moving ping pong ball to a designated place in three-dimensional space, which breaks through the previous two-dimensional limitation using a single CCD. This breakthrough can reduce the weight and cost of the robot arm. Therefore, this study aims to utilize the technology to grip moving targets on a moving platform for manpower cost reduction in the industry or agriculture domain in the future.
关键词： dynamic proportional-fuzzy controller,two-dimension limitation using a single CCD,Four-degree of freedom robot arm,forward and inverse kinematics,two-dimensional vision sensing method
更新于2025-09-11 14:15:04