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- 实验方案
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Tellurium-Doped, Mesoporous Carbon Nanomaterials as Transparent Metal-Free Counter Electrodes for High-Performance Bifacial Dye-Sensitized Solar Cells
摘要： Tellurium-doped, mesoporous carbon nanomaterials with a relatively high doping level were prepared by a simple stabilization and carbonization method in the presence of a tellurium metalloid. A transparent counter electrode (CE) was prepared using tellurium-doped, mesoporous carbon (TeMC) materials, and was directly applied to bifacial, dye-sensitized solar cells (DSSCs). To improve the performance of the bifacial DSSC device, CEs should have outstanding electrocatalytic activity, electrical conductivity, and electrochemical stability, as well as high transparency. In this study, to make transparent electrodes with outstanding electrocatalytic activity and electrical conductivity, various TeMC materials with di?erent carbonization temperatures were prepared by simple pyrolysis of the polyacrylonitrile-block-poly (n-butyl acrylate) (PAN-b-PBA) block copolymer in the presence of the tellurium metalloid. The electrocatalytic activity of the prepared TeMC materials were evaluated through a dummy cell test, and the material with the best catalytic ability was selected and optimized for application in bifacial DSSC devices by controlling the ?lm thickness of the CE. As a result, the bifacial DSSC devices with the TeMC CE exhibited high power conversion e?ciencies (PCE), i.e., 9.43% and 8.06% under front and rear side irradiation, respectively, which are the highest values reported for bifacial DSSCs to date. Based on these results, newly-developed transparent, carbon-based electrodes may lead to more stable and e?ective bifacial DSSC development without sacri?cing the photovoltaic performance of the DSSC device.
关键词： transparency,bifacial devices,mesoporous carbon,tellurium-doped,counter electrodes,dye-sensitized solar cells
更新于2025-09-16 10:30:52
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Coherent light matter interactions in nanostructure based active semiconductor waveguides operating at room temperature
摘要： Light matter coherent interactions require that the coherent state induced in the matter be maintained for the duration of the observation. The only way to induce and observe such interactions in room temperature semiconductors, where the coherence time is of the order of a few hundred femtoseconds, is to use ultrashort pulse excitations and an ultrafast characterization technique. For media comprising an ensemble of nanostructure semiconductors such as self-assembled quantum dots, the gain broadening inhomogeneity also affects the interaction. Moreover, when gain media in the form of an active waveguide, such as optical amplifiers, are used, the interaction is distributed and includes nonresonant incoherent phenomena that occur simultaneously with the coherent effects. Such a complex system can exhibit, nevertheless, clear coherent interactions even at room temperature. Using InAs/InP quantum dot and wirelike quantum dash amplifiers, Rabi oscillations, self-induced transparency, coherent control using spectral pulse shaping, Ramsey interference, and photon echo have been demonstrated. The characterization employed cross frequency resolved optical gating, and the experiments were accompanied by a comprehensive finite difference time domain model that solves the Maxwell and Lindblad equations. This work has major implications on the understanding of the details of dynamical processes in active semiconductor devices, on short pulse generation from semiconductor lasers, and on various future quantum devices.
关键词： active semiconductor waveguides,coherent control,self-induced transparency,Rabi oscillations,coherent light matter interactions,nanostructure,Ramsey interference,photon echo,room temperature
更新于2025-09-16 10:30:52
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Transmission control by asymmetric electromagnetically induced transparency-like metamaterials in transverse electromagnetic waveguide
摘要： We numerically and experimentally present passive and active electromagnetically induced transparency-like metamaterials in a TEM waveguide under normal excitation. Asymmetry of the metamaterial unit cell leads to the splitting of the radiative resonance. Surface current distributions are analyzed to account for each resonance. Moreover, by implementing a varactor diode to one of the gaps of the double-split ring resonator, electromagnetically induced transmission-like band is shifted in frequency and the corresponding bandwidth is modulated. A modulation ratio of 29.5 dB in transmission is experimentally demonstrated by only increasing the bias voltage 4 volts.
关键词： Surface current distributions,Radiative resonance,Electromagnetically induced transparency,Metamaterial,Modulation ratio
更新于2025-09-16 10:30:52
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Experimental Demonstration of Electromagnetically Induced Transparency in a Conductively Coupled Flexible Metamaterial with Cheap Aluminum Foil
摘要： We propose a conductively coupled terahertz metallic metamaterial exhibiting analog of electromagnetically induced transparency (EIT), in which the bright and dark mode antennae interact via surface currents rather than near-field coupling. Aluminum foil, which is very cheap and often used in food package, is used to fabricate our metamaterials. Thus, our metamaterials are also flexible metamaterials. In our design, aluminum bar resonators and aluminum split ring resonators (SRRs) are connected (rather than separated) in the form of a fork-shaped structure. We conduct a numerical simulation and an experiment to analyze the mechanism of the proposed metamaterial. The surface current due to LSP resonance (bright mode) flows along different paths, and a potential difference is generated at the split gaps of the SRRs. Thus, an LC resonance (dark mode) is induced, and the bright mode is suppressed, resulting in EIT. The EIT-like phenomenon exhibited by the metamaterial is induced by surface conducting currents, which may provide new ideas for the design of EIT metamaterials. Moreover, the process of fabricating microstructures on flexible substrates can provide a reference for producing flexible microstructures in the future.
关键词： Electromagnetically induced transparency,Surface currents,Terahertz,Metamaterial,Potential difference
更新于2025-09-12 10:27:22
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Highly Efficient and High Peak Transmittance Colorful Semitransparent Organic Solar Cells with Hybrid-Electrode-Mirror Microcavity Structure
摘要： Microcavity is an efficient approach to manufacture colorful semitransparent organic solar cells (ST-OSCs) with high color purity by tailoring the transmission spectrum to narrow peaks. However, in this type of colorful semitransparent devices, high power conversion efficiency (PCE) and high peak transmittance are not yet simultaneously achieved. This paper proposes a new type of microcavity structure to achieve colorful ST-OSCs with both high PCE and high peak transmittance, in which hybrid Au/Ag electrode is used as mirror and WO3 as spacer layer. Firstly, it is demonstrated that the hybrid Au/Ag electrode mirror brings about an improvement of 7.7% and 5.5% for PCE and peak transmittance respectively, when compared with those of the reference devices using Ag electrode mirror. Specifically, the PCE of the optimized devices reaches the satisfactory value of over 9%, and the peak transmittance is over 25%. This value of PCE is the highest one reported so far for the microcavity-based ST-OSCs with the same peak transmittance. Secondly, it is demonstrated that the second-order resonance of the microcavity can be used to improve the color purity of green ST-OSCs by narrowing the transmission peak and the combination of the second-order and third-order resonance can be used to construct colorful ST-OSCs with mixed colors. Thus, a novel approach is developed to tune the color of ST-OSCs, which is based on high-order resonance modes of the microcavity.
关键词： transparency,color mixing,color tunability,semitransparent organic solar cells,interface optimization,hybrid Au/Ag electrode,microcavity,efficiency
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Contaminant Free End-Capped Acetylene PMC for Sub-Doppler Spectroscopy
摘要： Gas-filled Hollow Core Photonic Cristal Fibres (HCPCF) or Photonic MicroCell (PMC) has proven to offer an outstanding gas-cell for laser metrology and spectroscopy applications. Sub-Doppler spectral features, generated via electromagnetically induced transparency (EIT) or saturated absorption (SA), have been generated in molecular gases despite the weak strength of their optical transitions, and an optical frequency reference with excellent accuracy has been demonstrated. Here, we report on fabrication and spectroscopic (EIT and SA spectroscopy) characterisation of contaminant free acetylene PMC where no He or glue is required. The assembly process of this PMC is based on end-capping both ends of a HCPCF by collapsing a sleeve capillary while the system is still connected to the vacuum preventing any air pollution. The end-cap is then polished and mounted onto FC/APC connectors for easy system integration.
关键词： saturated absorption,Hollow Core Photonic Cristal Fibres,Photonic MicroCell,electromagnetically induced transparency,sub-Doppler spectroscopy
更新于2025-09-12 10:27:22
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Dual-band electromagnetically induced transparency effect in asymmetrically coupled terahertz metamaterials
摘要： In this article, we numerically and experimentally investigate a metamaterial geometry capable of exhibiting dual-band electromagnetic induced transparency (EIT) effect in terahertz frequency regime. The meta-molecule unit consists of two asymmetric C resonators, placed alternately on both sides of a cut-wire (CW). The near field coupling between the CW and C resonators of the MM structure leads to the evolution of the dual-band EIT effect. We observe that the dual-band EIT effect can be modulated by changing the distance between the CW and the 2C resonators. Our study can play an important role in the development of multi-band slow light devices, modulators and also for sensing applications.
关键词： sensing,modulators,slow light devices,metamaterials,dual-band electromagnetically induced transparency,terahertz
更新于2025-09-12 10:27:22
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Color and transparency-switchable semitransparent polymer solar cells towards smart windows
摘要： Semitransparent polymer solar cells (ST-PSCs) have attracted worldwide attention owing to unique superiority in multiple utilization of incident light. However, the color of ST-PSCs is relatively uniform after fabrication, cannot be dynamically tuned in terms of application requirement. Herein, we demonstrate a high-efficiency ST-PSCs as a smart window, which can be reversibly switched on and off by a gasochromic tungsten trioxide/platinum (WO3/Pt) back reflector layer. The ST-PSCs can be switchable between colored and bleached states with fast response speed of sub-second during hydrogen exposure. Meanwhile, the color and transparency-switching enable light trapping enhancement in long wavelength range, which can systematically improve power conversion efficiency (PCE). As a result, the ST-PSCs contribute a PCE of 10.2 % and 9.1 % as well as corresponding average visible transmission (AVT) of 25.4 % and 33.8 % at colored state and bleached state, respectively, which can meet the visual aesthetics requirement well in building integrated photovoltaics. To the best of our knowledge, this is the first example for ST-PSCs that achieve both color-switching and light trapping. Furthermore, the smart windows facing to automobile sunroof are proposed to prove a practical application towards commercialization. We believe that smart windows with gasochromic functions can promise potential opportunities and directions for the future development of ST-PSCs.
关键词： gasochromic,semitransparent,color and transparency-switchable,smart window,polymer solar cell
更新于2025-09-12 10:27:22
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Proton acceleration due to laser plasma interactions from mass-limited spherical targets
摘要： The proton acceleration processes involved in the interaction of an ultrashort circularly polarized laser with a near-critical density spherical target are investigated in this paper using three dimensional particles in cell simulations. Both the target size and the target density are varied to understand their influence on the accelerated beam of protons. The target is efficiently heated by relativistic transparency, and a complicated interplay is observed between the participating interaction processes. The electron heating and recirculations help in the formation of shocks which exert a further push to the protons accelerated by the electrostatic sheath formed due to the ponderomotive force. A maximum peak proton energy of about 40 MeV is observed, which is the result of the cumulative effects of various acceleration mechanisms. Electron jets are observed in the forward laser direction for the larger target size, which suppresses the energy of the proton beams.
关键词： spherical targets,laser plasma interactions,electrostatic sheath,electron heating,proton acceleration,relativistic transparency,ponderomotive force,shock formation
更新于2025-09-12 10:27:22
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Triple mode coupling effect and dynamic tuning based on the zipper-type graphene terahertz metamaterial
摘要： We construct a laminated metamaterial structure of zipper-type monolayer graphene with silica which equipped with a distinctively dual plasmon induced transparency (PIT) phenomenon. The graphene pattern in this structure crafty connects with the electrode so that we can dynamically control the PIT response (via regulating the bias voltage that applied between the electrode and the substrate to control the graphene Fermi energy). In which, the range of voltage-regulate is calculated theoretically that proved to be a feasible measure for PIT response-tune. Then, the tuning discipline for this structure is summarized from the calculated result of coupled mode theory (CMT) deduced theoretical model and the simulation result. It is found that the structure possesses a great tuning performance within the tuning range we studied; also, such the structure ameliorates the monolayer graphene absorbance from 2.3% to about 50% within a broad dynamic frequency tuning range, the absorption peak frequency modulation depth is up to 45.46%. Besides, the group refractive index is discussed for reflecting the system capability of slow light, and the maximum of the coefficient can catch up to 595. Even if the impact of dielectric light- absorbance to slow light is taken into account, the slow light index at the transparent window is still as high as 200.
关键词： Absorbance,Plasmon induced transparency,Dynamic tuning,Slow light device,Graphene metamaterial
更新于2025-09-12 10:27:22