- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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FDTD Optical Simulation for Organic Solar Cells Incorporated with Antireflection Nanostructures
摘要： To improve the performance of organic photovoltaics, we investigate an integrated device design in which the hybrid antireflection structure, composed of a surface moth-eye nanotexture and a multilayer interference film, is applied with a high-refractive-index glass substrate. The moth eye texture with a relatively long period, which is near the bandgap wavelength of organic semiconductors, is used to enhance light absorption. We perform the optical finite-difference time-domain simulation for the integrated device and find the optimal layer configuration of the multilayer interference film to maximize the photocurrent generation. In addition, we compare the absorption spectrum of the integrated device and that of the device with only moth eye coating, and show that the integrated structure is beneficial to realize a high level of absorption relatively uniformly as function of wavelength.
关键词： Optimization,FDTD,Organic solar cell,Optical simulation
更新于2025-09-23 15:21:01
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[IEEE 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus) - St. Petersburg and Moscow, Russia (2020.1.27-2020.1.30)] 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus) - The Automated Test Bench for Studying the Parameters of a Laser Beam Near the Surface of Short-Focus Optical System
摘要： A general framework to combine the finite-difference time-domain (FDTD) and the finite-element time-domain (FETD) formulations, both based on the vector wave equation, is proposed. In contrast to the existing stable hybrid FETD-FDTD, there is no transition layer between two subdomains. In addition, the stability of the proposed approach is analytically proved. This framework allows combining different FDTD and FETD formulations together. Particularly, a fully unconditionally stable hybrid method is proposed, which is proved to be energy conservative too. The key ingredient is a finite-element tearing and interconnecting method for electromagnetic problems with a new interface condition that preserves the stability of the numerical method in each region. Several numerical examples are considered in order to validate the proposed methods. The numerical results match with the reference solutions very well in all cases.
关键词： Finite-difference time-domain (FDTD) method,finite-element tearing and interconnecting (FETI),nonoverlapping,finite-element time-domain (FETD) method
更新于2025-09-23 15:21:01
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Stable 3D FDTD method for arbitrary fully electric and magnetic anisotropic Maxwell's equations
摘要： We have developed a new fully anisotropic 3D FDTD Maxwell solver for arbitrary electrically and magnetically anisotropic media for piecewise constant electric and magnetic materials that are co-located over the primary computational cells. Two numerical methods were developed that are called nonaveraged and averaged methods, respectively. The nonaveraged method is first-order accurate, while the averaged method is second-order accurate for smoothly-varying materials and reduces to first order for discontinuous material distributions. For the standard FDTD field locations with the co-location of the electric and magnetic materials at the primary computational cells, the averaged method required development of the different inversion algorithms of the constitutive relations for the electric and magnetic fields. We provide a mathematically rigorous stability proof followed by extensive numerical testing that includes long-time integration, eigenvalue analysis, tests with extreme, randomly placed material parameters, and various boundary conditions. For accuracy evaluation, we have constructed a test case with an explicit analytic solution. Using transformation optics, we have constructed complex, spatially inhomogeneous geometrical object with fully-anisotropic materials and a large dynamic range of ?? and ??, such that a plane wave incident on the object is perfectly reconstructed downstream.
关键词： fully anisotropic,eigenvalue analysis,3D FDTD,stability,cloaking
更新于2025-09-23 15:21:01
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Imaginary-distance beam-propagation method based on Yee's mesh in cylindrical coordinates
摘要： An imaginary-distance beam-propagation method based on Yee’s mesh (ID-YM-BPM) is developed in cylindrical coordinates, in which the mode number of the eigenmode field is strictly considered. The ID-YM-BPM is second-order accurate with respect to the spatial mesh size. A segmented cladding fiber is analyzed, showing good agreement with other methods.
关键词： imaginary-distance procedure,Yee’s mesh,beam-propagation method (BPM),finite-difference time-domain (FDTD) method,cylindrical coordinates
更新于2025-09-23 15:21:01
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Plasmonic Nanoslit Arrays Fabricated by Serial Bideposition: Optical and Surface-Enhanced Raman Scattering Study
摘要： Recently, studies have been carried out to combine surface-enhanced Raman spectroscopy substrates that are based on either localized surface plasmon or surface plasmon polariton structures. By combining these two systems, the individual drawbacks of each can be overcome. However, the manufacturing methods involved so far are sophisticated, labor-intensive, expensive, and technically demanding. We propose a facile method for the fabrication of a flexible plasmonic nanoslit SERS sensor. We utilized the pattern on periodic optical disks as an inexpensive substitute for printing the periodic pattern on polydimethylsiloxane with soft imprint lithography. The Ag nanoslits were fabricated by serial bideposition using the dynamic oblique angle deposition technique. The nanoslit structures were physically and optically characterized, and the experimental results were compared to the results of the numerical simulation: Monte Carlo and finite-difference time-domain simulation. The AgNS samples showed excellent SERS performance with an enhancement factor of ～105 and a limit of detection of 5 × 10-7 g/mL for a Rhodamine 6G solution. Their biosensing capability was demonstrated by the sensing of bilirubin.
关键词： FDTD,Ag nanoslit,Monte Carlo simulation,dynamic oblique angle deposition,SERS
更新于2025-09-23 15:19:57
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An ultracompact 3??1 MMI power-combiner based on Si slot-waveguide structures
摘要： Today, photonic integrated circuits (PIC) that work with a high-modulation speed (100Gb/s and beyond) are required to use more optical power to overcome the losses. One solution is to use a high-level laser with a hundred milliwatts power. However, for a microchip circuit, this solution can be problematic due to the non-linear e?ects and high cost. Therefore, to solve this issue, we propose a new design of a 3×1 multimode interference (MMI) power combiner based on a slot waveguide structure that can utilize slot-waveguide technology for reducing losses. In this study, the full-vectorial beam propagation method (FV-BPM) was used to ?nd the optimal geometrical parameters of the MMI coupler, inputs/output taper, and the slot waveguide structure. Simulation results show that after light propagation of 9.82 μm the beam combiner e?ciency can reach 97.6 % working within the C-band range. Also, to reduce back re?ection losses an angled MMI was designed using a ?nite di?erence time domain (FDTD) method and results show a low back re?ection of 40 dB. This unique design can lead to an e?cient and compact combiner for multiple coherent sources that work with PIC chips.
关键词： Slot-waveguide,MMI,FDTD,FV-BPM,Power-combiner
更新于2025-09-23 15:19:57
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Compact Fully Metallic Millimeter-Wave Waveguide-Fed Periodic Leaky-Wave Antenna Based on Corrugated Parallel-Plate Waveguides
摘要： A three-dimensional (3-D) finite-difference time-domain (FDTD) algorithm is used in order to simulate ground penetrating radar (GPR) for landmine detection. Two bowtie GPR transducers are chosen for the simulations and two widely employed antipersonnel (AP) landmines, namely PMA-1 and PMN are used. The validity of the modeled antennas and landmines is tested through a comparison between numerical and laboratory measurements. The modeled AP landmines are buried in a realistically simulated soil. The geometrical characteristics of soil’s inhomogeneity are modeled using fractal correlated noise, which gives rise to Gaussian semivariograms often encountered in the field. Fractals are also employed in order to simulate the roughness of the soil’s surface. A frequency-dependent complex electrical permittivity model is used for the dielectric properties of the soil, which relates both the velocity and the attenuation of the electromagnetic waves with the soil’s bulk density, sand particles density, clay fraction, sand fraction, and volumetric water fraction. Debye functions are employed to simulate this complex electrical permittivity. Background features like vegetation and water puddles are also included in the models and it is shown that they can affect the performance of GPR at frequencies used for landmine detection (0.5–3 GHz). It is envisaged that this modeling framework would be useful as a testbed for developing novel GPR signal processing and interpretations procedures and some preliminary results from using it in such a way are presented.
关键词： rough surface,GPR,water puddles,modeling,FDTD,antipersonnel (AP) landmines,roots,dispersive,fractals,Antennas,bowtie,GprMax,grass,vegetation
更新于2025-09-23 15:19:57
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Simulation of three types of nanoparticles on solar cell structure model
摘要： In this paper, we systemically and numerically investigate the effects of three types of Nanoparticles on the efficiency of solar cells. Finite Difference Time Domain method has been implemented to compute the absorption spectra in such proposed solar cell structure. High efficiency has been achieved by optimizing the nanoparticles layer by tuning the fraction of nanoparticles on the host layer.
关键词： Thin-film solar cell,FDTD,absorption,metal nanoparticles,reflection
更新于2025-09-23 15:19:57
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Photocurrent improvement of an ultra-thin silicon solar cell using the localized surface plasmonic effect of clustering nanoparticles
摘要： The cluster-shaped plasmonic nanostructures are used to manage the incident light inside an ultra-thin silicon solar cell. Here, for the first time, spherical, conical, pyramidal, and cylindrical nanoparticles as a form of a cluster in the rear side of a thin silicon cell are simulated using finite difference time domain (FDTD) method. By calculating the optical absorption and hence the photocurrent, it is shown that the clustering of nanoparticles significantly improves them. The photocurrent enhancement is the result of the plasmonic effects of clustering the nanoparticles. For more comparison, at first, a cell with a single nanoparticle at the rear side is evaluated. Then four smaller nanoparticles are put around it to make a cluster. The photocurrents of 20.478, 23.186, 21.427, and 21.243 mA/cm2 are obtained for the cells using clustering conical, spherical, pyramidal, cylindrical NPs at the backside, respectively. These values are 13.987, 16.901, 16.507, 17.926 mA/cm2 for the cell with one conical, spherical, pyramidal, cylindrical nanoparticle at the rear side, respectively. So, clustering significantly improves the photocurrents. Finally, the distribution of the electric field and the generation rate for the proposed structures are calculated.
关键词： Clustering NPs,Localized surface plasmon resonance,light management,FDTD,Photocurrent,Plasmonic solar cell
更新于2025-09-23 15:19:57
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[IEEE 2018 International Conference on Electronics, Control, Optimization and Computer Science (ICECOCS) - Kenitra, Morocco (2018.12.5-2018.12.6)] 2018 International Conference on Electronics, Control, Optimization and Computer Science (ICECOCS) - Agent based simulation of electromagnetic waves propagation using the FDTD method
摘要： In recent years, multi-agent systems have taken an increasingly important place in computer science, whether in the field of artificial intelligence, distributed systems, robotics, or even in the environmental sciences, offering the opportunity to directly represent individuals, their behaviors and their interactions. The objective of this paper is the application of the techniques of the multi-agent approach in the simulation of the propagation of electromagnetic waves by FDTD method using Netlogo.
关键词： Electromagnetic,Propagation,FDTD,Multi-agents
更新于2025-09-19 17:15:36