- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Chemical Vapor Deposition for Nanotechnology || Atmospheric Pressure Chemical Vapor Deposition of Graphene
摘要： Recently, graphene has gained significant interest owing to its outstanding conductivity, mechanical strength, thermal stability, etc. Among various graphene synthesis methods, atmospheric pressure chemical vapor deposition (APCVD) is one of the best syntheses due to very low diffusivity coefficient and a critical step for graphene-based device fabrication. High-temperature APCVD processes for thin film productions are being recognized in many diversity technologies such as solid state electronic devices, in particular, high quality epitaxial semiconductor films for silicon bipolar and metal oxide semiconductor (MOS) transistors. Graphene-based devices exhibit high potential for applications in flexible electronics, optoelectronics, and energy harvesting. In this chapter, recent advances of APCVD-based graphene synthesis and their related applications will be addressed.
关键词： large-scale,atmospheric pressure chemical vapor deposition (APCVD),graphene,bilayer graphene (BLG),single-layer graphene (SLG),atmosphere pressure
更新于2025-09-23 15:22:29
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Low Voltage Graphene-Based Amplitude Modulator for High Efficiency Terahertz Modulation
摘要： In this paper, a high-e?ciency terahertz amplitude modulation device based on a ?eld-e?ect transistor has been proposed. The polarization insensitive modulator is designed to achieve a maximum experimental modulation depth of about 53% within 5 V of gate voltages using monolayer graphene. Moreover, the manufacturing processes are inexpensive. Two methods are adopted to improve modulation performance. For one thing, the metal metamaterial designed can e?ectively enhance the electromagnetic ?eld near single-layer graphene and therefore greatly promote the graphene’s modulation ability in terahertz. For another, polyethylene oxide-based electrolytes (PEO:LiClO4) acts as a high-capacity donor, which makes it possible to dope single-layer graphene at a relatively low voltage.
关键词： solid electrolyte,terahertz,single-layer graphene,transmittance,metamaterial,amplitude modulation,?eld-e?ect transistor
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu, China (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - A Hybrid Graphene-Metal IFA Antenna with Dynamically Tunable Operating Frequency at Microwave Freauencies
摘要： This paper presents a hybrid graphene-metal IFA antenna with dynamically tunable operating frequency. A small piece of single-layer graphene is used to connect with metal structure. This paper shows that the operating frequency of the antenna with special structure can be dynamically tuned by changing the surface resistance of single-layer graphene. The operating frequency of the antenna can be changed from L1 band of Global Positioning System to B3 band of BeiDou Navigation Satellite System.
关键词： hybrid graphene-metal antennas,microwave,dynamically tunable operating frequency,single-layer graphene
更新于2025-09-10 09:29:36
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Single-layer graphene-coated gold chip for electrochemical surface plasmon resonance study
摘要： Surface plasmon resonance (SPR) employs a gold (Au) thin film (ca. 50 nm in thickness) chip to generate a surface plasmonic wave (SPW) for in situ monitoring of the interface/surface, which makes it intrinsically compatible with electrochemistry for combined electrochemical surface plasmon resonance (EC-SPR) investigations. However, conventional SPR Au chips suffers from a high background signal, narrow electrochemical window, and limited electrochemical stability. Presented in this work is a novel SPR chip composed of the Au/long-chain alkane thiol self-assembled monolayer/single-layer graphene (Au/SAM/G) sandwich architecture to address these problems. On this chip, the single-layer graphene serves as a working electrode for electrochemical measurement, and the underlying Au film serves as the SPW support for SPR monitoring; the sandwiched thiol monolayer enables the electrical separation of the graphene and Au film to protect the Au film from electrochemical polarization. Our experiment indicates that the electrochemical window of such a chip extends beyond the hydrogen/oxygen evolution reaction potential on Au with significantly improved electrochemical stability and suppressed background signal. Moreover, its intrinsic SPR sensitivity is completely reserved even compared to that of the conventional SPR Au chip. This Au/SAM/G chip may offer a valuable solution to the EC-SPR investigations in harsh conditions.
关键词： Electrochemical surface plasmon resonance,Single-layer graphene,Electrochemical window,Chip
更新于2025-09-10 09:29:36
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Single layer graphene for estimation of axial spatial resolution in confocal Raman microscopy depth profiling
摘要： Single layer graphene (SLG), with its angstrom-scale thickness and strong Raman scattering cross section, was adapted for measurement of the axial (Z-direction) probe beam profile in confocal Raman microscopy depth-profiling experiments. SLG adsorbed to a glass microscope coverslip (SLG/SiO2) served as a platform for estimation of axial spatial resolution. Profiles were measured by stepping the confocal probe volume through the SLG/SiO2 interface while measuring Raman scattering from the sample. Using a high numerical aperture (1.4 NA) oil immersion objective, axial profiles were derived from the graphene 2D vibrational mode and fit to a Lorentzian instrument response function (IRF). Subsequently, the Z-direction spatial resolution in depth-profiling studies of polymer interfaces was estimated through convolution of the Lorentzian IRF with a step function representing the ideal junction separating the phases of interest. In the study of a bipolar polymer membrane, confocal Raman depth profiles of the AEM/CEM (anion exchange membrane / cation exchange membrane) interface show the transition region is broader than the limiting response and are consistent with roughness at the boundary on the order of a few micrometers. Using ClO4- as a Raman active mobile ion probe, application of self-modeling curve resolution (SMCR) to spectral datasets within a profile showed ClO4- ions track the spatial distribution of the AEM phase. Finally, in measurements on a liquid-solid interface formed between 1-octanol and a polydimethylsiloxane (PDMS) membrane, the IRF derived from fitting the experimental profile was slightly narrower than those obtained from profiling SLG, indicating the potential to use polymer-liquid interfaces formed from widely available materials and reagents for estimation of axial spatial resolution in confocal Raman depth-profiling.
关键词： Axial spatial resolution,Polymer interfaces,Confocal Raman microscopy,Single layer graphene,Bipolar membrane,Depth profiling
更新于2025-09-04 15:30:14