- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Bipolar fluorophores based on intramolecular charge-transfer moieties of sulfone for nondoped deep blue solution-processed organic light-emitting diodes
摘要： Dipolar emitters exhibited excellent performance in organic light-emitting diode (OLED). However, these molecules had intramolecular charge-transfer (ICT) properties, which posed challenge to obtain deep blue emission. In this study, three fluorophores were designed by introducing carbazole and diphenylamine as electron donors and sulfone as electron acceptor due to their mild charge-accepting properties and twisted angles. These materials appeared almost in vertical angles of the dihedral configuration, and exhibited high thermal and electrochemical stability, suitable for solution-processed OLED. The solution-processed non-doped devices based on these three emitters were realized, where two emissions within the standard deep blue emission range were achieved with the Commission International e de l’Eclairage (CIE) coordinates of (0.16, 0.12) and (0.16, 0.15).
关键词： bipolar fluorophores,intramolecular charge-transfer,deep blue,single layer,organic light-emitting diodes
更新于2025-09-16 10:30:52
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Site-selective Atomic Layer Precision Thinning of MoS2 via Laser-Assisted Anisotropic Chemical Etching
摘要： Various exotic optoelectronic properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs) strongly depend on their number of layers, and typically manifest in ultra-thin few- or mono-layer formats. Thus, precise manipulation of thickness and shape is essential to fully access their potential in optoelectronic applications. Here, we demonstrate site-selective atomic layer precision thinning of exfoliated MoS2 flake by laser. The oxidation mediated anisotropic chemical etching initiated from edge defects and progressed by controlled scanning of the laser beam. Thereby, the top-most layer can be preferentially removed in designed patterns without damaging the bottom flake. In addition, we could monitor the deceleration of the thinning by in-situ reflectance measurement. The apparent slow-down of the thinning rate is attributed to the sharp reduction in the temperature of the flake due to thickness dependent optical properties. Fabrication of monolayer stripes by laser thinning suggests potential applications in non-linear optical gratings. The proposed thinning method would offer a unique and rather straightforward way to obtain arbitrary shape and thickness of TMDCs flake for various optoelectronic applications.
关键词： Laser Thinning,Single layer precision thinning,Non-linear optical grating,Anisotropic chemical etching,TMDCs,MoS2
更新于2025-09-12 10:27:22
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Substrate Temperature Dependence of the Properties of Single-layer MoS2 Film deposited by Using Pulsed Laser Deposition
摘要： Single-layer MoS2 ?lms were deposited on sapphire substrates by using pulsed laser deposition. The substrate temperature dependence of the structural, optical and photoluminescence properties of single-layer MoS2 ?lms was investigated. An increased substrate temperature improved the surface morphology and the crystal quality of the MoS2 ?lms. Moreover, the absorption and the photoluminescence properties of the MoS2 ?lms were enhanced. In addition, the mechanism underlying the e?ect of substrate temperature on the properties of single-layer MoS2 ?lms is discussed.
关键词： Optical properties,Substrate temperature,Crystal quality,Single-layer MoS2 ?lm,Photoluminescence properties
更新于2025-09-12 10:27:22
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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 Single Layer Broadband Reflectarray for Dual Polarizing Beam Splitting
摘要： A single layer broadband reflectarray is proposed, which is capable of generating independent reflect beams according to the polarization. The reflectarray element is composed of two sets of paralleled dipoles overlapping orthogonally on the surface of the substrate, and each set of the dipoles provide phase compensation for the certain polarization. Independent phase distributions can be achieved respectively on the same surface to perform separate beams with an included angle of 30 degrees between TE and TM polarizations. Operating as a polarizing reflect-beam splitter, a broadband performance (11.3-13.1 GHz) is acquired in simulation and the measurement result is exhibited.
关键词： parallel dipole,broadband,orthogonal polarization,single layer reflectarray,beam splitter
更新于2025-09-10 09:29:36
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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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Nanoscratch on Single-layer MoS2 Crystal by Atomic Force Microscopy: Semi-circular to Periodical Zigzag Cracks
摘要： The fracture behaviors of single-layer molybdenum disulfide (MoS2) grown on SiO2/Si wafer by chemical vapor deposition (CVD) were systematically investigated here via a technique that combining AFM-based nanoscratch tests with friction force microscopy (FFM). To get a complete cognition of fracture behavior and deepen the understanding of mesoscopic anisotropy of the mechanical failure of 2D materials, the gradual process of fracture behavior on nanoscale layered films and confirmed the different fracture stages in the process, nanoscratch with progressive and constant force was done step by step. The radius of AFM tip we used is ~10 nm which is relatively blunt to produce a tensile fracture rather than pierce the film at the initial stage. As a result, there were novel crack modes with specific normal load in the surface of CVD-grown MoS2: semi-circular and periodical zigzag cracks, and both crack modes exhibit anisotropy during the generation and propagation.
关键词： nanoscratch,periodical zigzag crack,Single-layer,semi-circular crack,MoS2
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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A 400-GHz Wideband High-Gain Quartz-Based Single-Layered Folded Reflectarray Antenna for Terahertz Applications
摘要： Compact high-gain antennas are highly desired in the high speed terahertz (THz) wireless system, especially for the space limited application such as the high speed inter-link inside the high density wireless communication base station. To this end, a 400-GHz folded reflectarray (FRA) antenna with high gain, high aperture efficiency and compact profile is proposed in this paper. It is composed of a feed source, a single-layered reflectarray using a lithography process on quartz, and a wire-grid polarizer implemented by the printed-circuit-board (PCB) technology. A 3-D printed fixture is used to assemble all parts together. In order to design accurately the THz electromagnetic properties of the supporting dielectric materials are extracted by using a THz time-domain spectrometer system. Then, a single-layered phasing element, made up of a pair of orthogonally I-shaped structures with an open square ring, is proposed and designed based on the extracted material characteristics. Both phase compensation and polarization conversion can be realized by the proposed unit cell. A reflectarray is designed by using the proposed phasing element with the conventional array synthesizing theory, and a THz grid polarizer is designed with strips on a 0.127 mm Taconic TLY-5 substrate. The THz grid is placed in front of the THz feed and the reflectarray, which is fully reflective to the feed and transparent to the reflectarray. All components of the FRA antenna have been fabricated and assembled. Experiments show that the FRA prototype has a peak gain of 33.66 dBi at 400 GHz with an aperture efficiency of 33.65%, and a 3-dB gain bandwidth of 16% (357-421 GHz).
关键词： terahertz,3-D printing,high-gain,material characteristics,quartz substrate,single-layer,Folded reflectarray antenna,THz time-domain spectrometer
更新于2025-09-10 09:29:36
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[IEEE 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC) - Xuzhou, China (2018.7.21-2018.7.24)] 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC) - A Transition Beween Single-Layer Substrate Integrated Image Guide and Coaxial Probe
摘要： The substrate integrated image guide (SIIG) is a planar transmission line with low-loss and high-Q properties. To reduce the fabrication complexity, the SIIG realized by the single-layer PCB technology is introduced. The differences between this type of SIIG and the conventional one are analyzed. A feasible method is proposed to minimize the additional leakage loss caused by the single-layer PCB process and achieve the similar performance compared with the conventional SIIG. A SIIG line working from 13.2GHz to 14.8GHz is designed utilizing this method. Then, a single-layer transition from a coaxial probe to the SIIG is presented. A 132.2 mm long single-layer PCB-based SIIG with such a transition is designed and fabricated. The measured results show that insertion loss is better than 4.25dB while the return loss is under –10dB from 13.2 GHz to 14.8 GHz.
关键词： PCB techonology,substrate integrated image line (SIIG),co-axial probe feeding,single-layer transition
更新于2025-09-09 09:28:46
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[IEEE 2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI) - Bangalore, India (2018.9.19-2018.9.22)] 2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI) - A Modified Frequency Selective Surface Band-stop Filter for Ultra-wideband Applications
摘要： A modi?ed design of a single-layer ultra-wideband (UWB) Frequency Selective Surface (FSS) re?ector is presented for microwave applications. The proposed FSS unit cell consists of a square-loop and a ring printed on opposite sides of a low-cost FR-4 substrate. With the optimized dimensions of the elements, the proposed FSS design provides a stop-bandwidth of 11.94 GHz (5.24-17.18 GHz). It is observed from simulation results that the proposed FSS design has a linear decreasing phase response in the desired band. Furthermore, the presented design provides a stable frequency response up to 450 oblique angle of incidence for both perpendicular (TE) and parallel (TM) polarizations.
关键词： Oblique incidence,Single-layer,FSS re?ector,Ultra-wideband
更新于2025-09-09 09:28:46