- 标题
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- 实验方案
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Roll-to-Roll Slot-Die Coated P-I-N Perovskite Solar Cells Using Acetonitrile Based Single Step Perovskite Solvent System
摘要： Roll-to-roll coating of all active layers is demonstrated for a P-I-N perovskite solar cell stack, using a single step perovskite ink with an acetonitrile solvent system and flexible plastic substrate. A slot-die coating roll-to-roll process (with a common coating speed for all layers) is developed by using appropriate length meniscus guides as part of the coating head for each ink rheology. High performance devices are demonstrated with four roll-to-roll slot-die coated layers and evaporated top electrode. The drying conditions of the perovskite layer are optimized and found to be critical to achieving good performance. Multi solvent blend systems for the electron collection layer are developed that are more industrially compatible than the commonly used chlorobenzene solvent system and make use of a gradient of solvent volatilities to give both good macro film formation and rapid drying. A stabilised power conversion efficiency of 12.2% is demonstrated, that is the highest reported to date for devices with all layers other than the top electrode deposited roll-to-roll. This work demonstrates the feasibility of a roll-to-roll fabrication process for perovskite solar cells that could be transferred to a fully inline roll-to-roll process with all coating and drying stages made sequentially on one line running at a common coating speed and further demonstrates the potential to produce high efficiency photovoltaics using roll-to-roll fabrication methods.
关键词： Stabilised power conversion efficiency,Perovskite solar cells,Slot-die coating,Roll-to-roll,Acetonitrile solvent system
更新于2025-09-23 15:21:01
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Multibeam Monopulse SIW Slot Array Antenna
摘要： A multibeam slot array antenna is proposed in the 10-GHz band for a monopulse tracking system with resolution enhancement techniques. The antenna architecture combines a four-subarray SIW slot antenna, a multibeam-forming network of microstrip Rotman lens array, and a SIW comparator of four-quadrant monopulse technique. A method to form difference patterns in both E-plane and H-plane for mutibeams is presented, and the method can improve the accuracy of angle detection for all beams. The key point of the method is to compensate the phase difference caused by the beam deflection between two subarrays (quadrants) by constraining input delay lines of the Rotman lens array. To validate the proposed concepts, an antenna prototype is realized and measured. The experimental results demonstrate a scanning range of ±36° with -5 dB crossover level between two adjacent sum beams in the E-plane. The corresponding beams of difference pattern are generated in E-plane and H-plane via the monopulse comparator to enhance angle resolution. The multibeam monopulse system can achieve gains between 21.7 dBi and 23.5 dBi for all sum beams at the center frequency of 10 GHz. The lobe imbalances are less than 1.1 dB and null depths are lower than -16 dB for all difference patterns. This multibeam monopulse slot antenna can be applied in radar and communication systems requiring beam-scanning capabilities and target tracking.
关键词： slot array,Rotman lens,monopulse antenna,substrate integrated waveguide (SIW),Multibeam antenna
更新于2025-09-23 15:21:01
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DESIGN AND REALIZATION OF CIRCULAR POLARIZED SIW SLOT ARRAY ANTENNA FOR CUBESAT INTERSATELLITE LINKS
摘要： This paper presents the design and fabrication of an antenna based on Substrate Integrated Waveguide (SIW) for intersatellite crosslinks in C-band. The entire antenna consists of two elements of SIW slots array that is fed by a hybrid 3 dB directional coupler. The entire SIW slots array antenna is circularly polarized (CP), and each element has four longitudinal slots. The element’s e?ective ?eld matching is realized with a microstrip to SIW transition. The antenna design has been evaluated with its return loss, gain plot, and radiation pattern characteristics to validate the fabricated antenna. The fabricated prototype antenna radiates a left-handed circularly polarized (LHCP) electromagnetic wave with the peak gain of 5 dB and o?ers approximately 2% AR bandwidth around 5 GHz.
关键词： circularly polarized (CP),intersatellite links,slot array antenna,CubeSat,Substrate Integrated Waveguide (SIW)
更新于2025-09-23 15:21:01
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A PENTA-BAND REJECT INSIDE CUT KOCH FRACTAL HEXAGONAL MONOPOLE UWB MIMO ANTENNA FOR PORTABLE DEVICES
摘要： In this paper, a novel compact hexagonal shaped ultra-wideband multiple-input multiple-output (UWB-MIMO) Koch fractal antenna is designed with penta-band rejection characteristics for portable devices. The antenna rejects the C-band downlink frequency from 3.7–4 GHz, the C-band uplink frequency from 5.75–6.05 GHz and the satellite bands from 7.45 to 8.4 GHz. The band 7.45–7.55 GHz is used by the meteorological satellite service for the geostationary satellite services. The band 7.75–7.9 GHz is used by the meteorological satellite service for non-geostationary satellite services. The band 8.025–8.4 GHz is used by the Earth exploration satellites for geostationary satellite services. The C-band and satellite bands interfere with the UWB and have been rejected using a band reject ?lter. A spiral shaped slot is introduced inside the fractal hexagonal monopole to introduce band reject characteristics. The band suppression and widening of the impedance bandwidth are achieved by using defected ground structures. The antenna has wideband impedance matching with S11 < ?10 dB in the UWB frequency range from 3.1 to 13.6 GHz and has a low mutual coupling with S21 < ?19 dB. The antenna has very low envelope correlation coe?cient of less than 0.17 and low capacity loss of 0.254, which proves that the MIMO antenna shows good diversity performance.
关键词： Koch fractal,defected ground structures,UWB-MIMO,spiral slot,penta-band rejection
更新于2025-09-23 15:21:01
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ELECTRICALLY RECONFIGURABLE RADIATION PATTERNS OF SLOT ANTENNA ARRAY USING AGILE PLASMA WALL
摘要： In this paper, an antenna with recon?gurable radiation pattern in the H-plane at 2.45 GHz for high power applications is presented. It is based on a 3-slot array in the E-plane covered partially with a wall of plasma in order to reduce the length of the slots and consequently ensure electrically a modi?cation of the radiation pattern in the H-plane. The power distribution of the array is ensured with a power splitter.
关键词： recon?gurable radiation pattern,high power applications,slot antenna array,plasma wall
更新于2025-09-23 15:21:01
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NOVEL CIRCULARLY POLARIZED SIW CAVITY-BACKED ANTENNA WITH WIDE CP BEAMWIDTH BY USING DUAL ORTHOGONAL SLOT SPLIT RINGS
摘要： A circularly polarized (CP) substrate integrated waveguide (SIW) cavity-backed antenna based on dual concentric, orthogonal slot split ring resonators is proposed and experimentally studied. The circularly polarized wave is generated by two split ring-slots etched in the upper metal layer of the SIW cavity resonator. These two slots are excited by a coaxial probe located in the gap of the external slot split ring to radiate the right-handed circularly polarized (RHCP) wave. By rotating the dual split slot ring resonators and the probe by 45 degrees relative to the backed cavity, a better match characteristic and a slightly higher radiation gain are obtained. Because of the concentricity of radiant split ring slots, the beamwidth of the circular polarization is obviously increased. From the experimental results, the impedance bandwidth was 10.8% for the re?ection coe?cient less than ?10 dB, the axial ratio (AR) bandwidth was 1.54% for the AR less than 3 dB, and the RHCP gain was 4.44 dBic. Moreover, the 3-dB axial ratio beamwidth at the centre frequency of 10.40 GHz has been extended to 142? in the angular range from ?78? to +64?.
关键词： circularly polarized,wide CP beamwidth,SIW cavity-backed antenna,dual orthogonal slot split rings
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Singapore, Singapore (2019.8.28-2019.8.30)] 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Compact Polarization Beam Splitter Based on a 3-Waveguide Directional Coupler with Broad Bandwidth Performance
摘要： Compact polarization beam splitter based on a 3-waveguide directional coupler with broad bandwidth performance
关键词： slot waveguide,directional coupler,Polarization beam splitter
更新于2025-09-23 15:19:57
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Effect of Solvent Additives on the Morphology and Device Performance of Printed Non-fullerene Acceptor Based Organic Solar Cells
摘要： Printing of active layers of high-efficiency organic solar cells and morphology control by processing with varying solvent additive concentrations are important to realize real-world use of bulk-heterojunction photovoltaics as it enables both, up-scaling and optimization of the device performance. In this work, active layers of the conjugated polymer with benzodithiophene units PBDB-T-SF and the non-fullerene small molecule acceptor IT-4F are printed using meniscus guided slot-die coating. 1,8-diiodoctane (DIO) is added to optimize the power conversion efficiency (PCE). The effect on the inner nano-structure and surface morphology of the material is studied for different solvent additive concentrations with grazing incidence small angle X-ray scattering (GISAXS), grazing incidence wide angle X-ray scattering (GIWAXS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Optical properties are studied with photoluminescence (PL), UV/Vis absorption spectroscopy and external quantum efficiency (EQE) measurements and correlated to the corresponding PCEs. The addition of 0.25 vol% DIO enhances the average PCE from 3.5 to 7.9 % whereas at higher concentrations the positive effect is less pronounced. A solar cell performance of 8.95 % is obtained for the best printed device processed with an optimum solvent additive concentration. Thus, with the large-scale preparation method printing similarly well working solar cells can be realized as with the spin-coating method.
关键词： slot-die coating,solvent additives,small molecule acceptor,high-efficiency organic solar cells,printed organic solar cells
更新于2025-09-23 15:19:57
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Design of novel thiazolothiazole-containing conjugated polymers for organic solar cells and modules
摘要： One of the major challenges in the field of organic photovoltaics is associated with high-throughput manufacturing of efficient and stable organic solar cells. Practical realization of technologies for production of large-area organic solar cells requires the development of novel materials with a defined combination of properties ensuring sufficient reliability and scalability of the process in addition to good efficiency and operation stability of the devices. In this work, we designed two novel polymers comprising thiazolothiazole units and investigated their performance as absorber materials for organic solar cells and modules. Optimized small-area solar cells based on P1/[70]PCBM ([6,6]-phenyl-C71-butyric acid methyl ester) blends exhibited promising power conversion efficiency (PCE) of 7.5%, while larger area modules fabricated using slot die coating showed encouraging PCE of 4.2%. Additionally, the fabricated devices showed promising outdoor stability maintaining 60–70% of the initial efficiency after 20 sun days being exposed to natural sunlight at the Negev desert. The obtained results feature the designed polymer P1 as a promising absorber material for a large-scale production of organic solar cells under ambient conditions.
关键词： Thiazolothiazole,Conjugated polymers,Photovoltaic modules,Organic solar cells,Slot-die coating
更新于2025-09-23 15:19:57
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[IEEE 2019 34th Symposium on Microelectronics Technology and Devices (SBMicro) - Sao Paulo, Brazil (2019.8.26-2019.8.30)] 2019 34th Symposium on Microelectronics Technology and Devices (SBMicro) - Effect of the dopant location and the number of Bragg mirrors on the performance of superlattice infrared photodetectors
摘要： This paper presents a substrate integrated waveguide Butler matrix with a modi?ed hybrid coupler, operating from 28 to 32 GHz. The modi?ed hybrid coupler is realized by using 90? hybrid coupler followed by a ?45? compensating phase shifter. Thus, 45?/135? output phase differences can be obtained using this type of coupler. Compared with the equal-length unequal-width phase shifter, the compensating phase shifter exhibits better phase characteristics, with only 3? phase error over 28–32 GHz. Because the phase of compensating phase shifter is not realized by taking the phase introduced by the crossover as a reference, it gives great ?exibility to the design of compensating phase shifter. Adopting the modi?ed hybrid coupler, the designed Butler matrix features the output phases with peak to peak error of 13? and wideband performance from 28 to 32 GHz. The slot array fed by the Butler matrix can radiate four slanted beams with acceptable measured gains, in the range of 9.7～12 dBi for port 1 excitation and 8.4～11.1 dBi for port 2 excitation. The radiated beams can reach a wide azimuthal coverage between ±61?.
关键词： Butler matrix,Modi?ed hybrid coupler,substrate integrated waveguide (SIW),compensating phase shifter,slot array antenna
更新于2025-09-23 15:19:57