Ultra-Low-Reflective, Self-Cleaning Surface by Fabrication Dual-Scale Hierarchical Optical Structures on Silicon

An integrated functional anti-reflective surface is of great significance for optical and optoelectronic devices. Hence, its preparation has attracted great attention from many researchers. This study combined wet alkaline etching approaches and reactive ion etching (RIE) techniques to create a dual-scale hierarchical anti-reflective surface on silicon substrates. The effect of RIE time on surface morphology and optical performance was investigated using multiple characterization forms. The optimal parameters for the fabrication of dual-scale structures by the composite etching process were explored. The silicon surface with a dual-scale structure indicated excellent anti-reflective properties (minimum reflectivity of 0.9%) in the 300 to 1100 nm wavelength range. In addition, the ultra-low reflection characteristic of the surface remained prominent at incident light angles up to 60°. The simulated spectra using the finite difference time domain (FDTD) method agreed with the experimental results. Superhydrophobicity and self-cleaning were also attractive properties of the surface. The functionally integrated surface enables silicon devices to have broad application prospects in solar cells, light emitting diodes (LEDs), photoelectric detectors, and outdoor equipment.

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A SILVER-COATED SINUSOIDAL SUB-WAVELENGTH STRUCTURE WITH POLARIZATION FEATURE FOR LIGHT EMITTING DIODE

Surface Review and Letters ◽

10.1142/s0218625x09012998 ◽

2009 ◽

Vol 16 (04) ◽

pp. 631-634 ◽

Cited By ~ 1

Author(s):

CHENG-HAO KO ◽

JIAN-SHIAN LIN ◽

CHANG-TAI CHEN ◽

NIEN-PO CHEN

Keyword(s):

Light Emitting Diode ◽

Red Light ◽

Fdtd Method ◽

Dielectric Materials ◽

Transmission Efficiency ◽

Light Emitting ◽

Light Region ◽

Fluorescence Efficiency ◽

Difference Time ◽

Sub Wavelength

A two-dimensional sub-wavelength grating (SWG) is fabricated on light-emitting diodes (LEDs). The SWG is simulated by finite-difference time-domain (FDTD) method. The SWG surface has silver-coated dielectric materials with sinusoidal structures, 175 nm period and 125 m depth of groove. When the incident wave is in the red light region of 600–700nm, the transmission efficiency of TM propagated light will reach 0.82. If this SWG structure is applied in LCD direct backlight module, the lower polarization piece can be replaced and fluorescence efficiency of LED can be improved.

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Transparent, self-cleaning and waterproof surfaces with tunable micro/nano dual-scale structures

Nanotechnology ◽

10.1088/0957-4484/27/35/355701 ◽

2016 ◽

Vol 27 (35) ◽

pp. 355701 ◽

Cited By ~ 11

Author(s):

Yujin Lee ◽

Eun-Ah You ◽

Young-Geun Ha

Keyword(s):

Scale Structures ◽

Self Cleaning ◽

Dual Scale

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Designing the Hotspots Distribution by Anisotropic Growth

Molecules ◽

10.3390/molecules26010187 ◽

2021 ◽

Vol 26 (1) ◽

pp. 187

Author(s):

Tianshun Li ◽

Renxian Gao ◽

Xiaolong Zhang ◽

Yongjun Zhang

Keyword(s):

Au Nanoparticles ◽

Fdtd Method ◽

Polarization Dependence ◽

Noble Metal Nanoparticles ◽

Oblique Angle Deposition ◽

Matlab Simulation ◽

Different Shapes ◽

Plasma Enhancement ◽

Difference Time ◽

Good Agreement

Changing the morphology of noble metal nanoparticles and polarization dependence of nanoparticles with different morphologies is an important part of further research on surface plasma enhancement. Therefore, we used the method based on Matlab simulation to provide a simple and effective method for preparing the morphologies of Au nanoparticles with different morphologies, and prepared the structure of Au nanoparticles with good uniformity and different morphologies by oblique angle deposition (OAD) technology. The change of the surface morphology of nanoparticles from spherical to square to diamond can be effectively controlled by changing the deposition angle. The finite difference time domain (FDTD) method was used to simulate the electromagnetic fields of Au nanoparticles with different morphologies to explore the polarization dependence of nanoparticles with different shapes, which was in good agreement with Raman spectrum.

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Application of the finite-difference time-domain (FDTD) method with local grid refinement to nanostructure design

10.1117/12.590765 ◽

2005 ◽

Author(s):

Aramais R. Zakharian ◽

Jerome V. Moloney ◽

Colm Dineen ◽

Moysey Brio

Keyword(s):

Finite Difference ◽

Time Domain ◽

Finite Difference Time Domain ◽

Fdtd Method ◽

Grid Refinement ◽

Local Grid Refinement ◽

Local Grid ◽

Difference Time

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Three-Dimensional Finite-Difference Time-Domain Method Modeling of Nanowire Optical Probe

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.602-605.3359 ◽

2014 ◽

Vol 602-605 ◽

pp. 3359-3362

Author(s):

Chun Li Zhu ◽

Jing Li

Keyword(s):

Finite Difference ◽

Time Domain ◽

Finite Difference Time Domain ◽

Incident Light ◽

Near Field ◽

Three Dimensional ◽

Polarization Direction ◽

Near Field Imaging ◽

Difference Time ◽

Field Imaging

In this paper, output near fields of nanowires with different optical and structure configurations are calculated by using the three-dimensional finite-difference time-domain (3D FDTD) method. Then a nanowire with suitable near field distribution is chosen as the probe for scanning dielectric and metal nanogratings. Scanning results show that the resolution in near-field imaging of dielectric nanogratings can be as low as 80nm, and the imaging results are greatly influenced by the polarization direction of the incident light. Compared with dielectric nanogratings, metal nanogratings have significantly enhanced resolutions when the arrangement of gratings is perpendicular to the polarization direction of the incident light due to the enhancement effect of the localized surface plasmons (SPs). Results presented here could offer valuable references for practical applications in near-field imaging with nanowires as optical probes.

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The Lightning Electromagnetic Pulse Coupling Effect Inside the Shielding Enclosure With Penetrating Wire

Frequenz ◽

10.1515/freq-2016-0278 ◽

2017 ◽

Vol 71 (11-12) ◽

Cited By ~ 1

Author(s):

Xue Jiao ◽

Bo Yang

Keyword(s):

Electromagnetic Pulse ◽

Coupling Effect ◽

Fdtd Method ◽

Current Source ◽

Low Frequency ◽

Frequency Component ◽

Lightning Current ◽

Proper Size ◽

Practical Engineering ◽

Difference Time

AbstractTo study the lightning electromagnetic pulse (LEMP) coupling and protection problems of shielding enclosure with penetrating wire, we adopt the model with proper size which is close to the practical engineering and the two-step finite-difference time-domain (FDTD) method is used for calculation in this paper. It is shown that the coupling voltage on the circuit lead inside the enclosure increases about 34 dB, when add 1.0 m long penetrating wire at the aperture, comparing with the case without penetrating wire. Meanwhile, the waveform, has the same wave outline as the lightning current source, shows that the penetrating wire brings a large number of low frequency component into the enclosure. The coupling effect in the enclosure will reduce greatly when penetrating wire has electrical connection with the enclosure at the aperture and the coupling voltage increase only about 12 dB than the case without penetrating wire. Moreover, the results show that though the waveguide pipe can reduce the coupling effect brought by the penetrating wire, the exposing part of penetrating wire can increase the coupling when the penetrating wire outside the enclosure is longer than the waveguide pipe and the longer the exposing part is, the stronger the coupling is.

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Trapping of Nano-Particles Using a Near-Field Optical Fiber Probe

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.516.90 ◽

2012 ◽

Vol 516 ◽

pp. 90-95

Author(s):

Bing Hui Liu ◽

Li Jun Yang ◽

Yang Wang

Keyword(s):

Near Field ◽

Fdtd Method ◽

Laser Wavelength ◽

Nano Particles ◽

Minimum Size ◽

Fiber Probe ◽

Circular Shape ◽

Optical Fiber Probe ◽

Fibre Probe ◽

Difference Time

By employing a generalization of the conservation law for momentum using the finite difference time domain (FDTD) method, the feasibility of using a near-field optical fibre probe to create near-field optical trapping is investigated. Numerical results indicate that the scheme is able to trap nanoparticles with diameters of tens of nanometres in a circular shape with lower laser intensity. Using the built system with a tapered metal-coated fibre probe, 120 nm polystyrene particles are trapped in a multi-circular shape with a minimum size of 400 nm. They are at a resolution of λ/7 (λ: laser wavelength) and d (d: tip diameter of fiber probe), respectively.

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Investigation of Contact Conditions During Stamping of a Thin Plate

Volume 2A: Advanced Manufacturing ◽

10.1115/imece2020-24547 ◽

2020 ◽

Author(s):

Harshal Y. Shahare ◽

Rohan Rajput ◽

Puneet Tandon

Keyword(s):

Wave Propagation ◽

Material Properties ◽

High Speed ◽

Fdtd Method ◽

Propagation Model ◽

Transmitted Wave ◽

Two Dimensional ◽

Contact Conditions ◽

Simulation Based ◽

Difference Time

Abstract Stamping is one of the most used manufacturing processes, where real-time monitoring is quite difficult due to high speed of the mechanical press, which leads to deterioration of the accuracy of the products In the present work, a method is developed to model elastic waves propagation in solids to measure contact conditions between die and workpiece during stamping. A two-dimensional model is developed that reduces the wave propagation equations to two-dimensional equations. To simulate the wave propagation inside the die-workpiece model, the finite difference time domain (FDTD) method and modified Yee algorithm has been employed. The numerical stability of the wave propagation model is achieved through courant stability condition, i.e., Courant-Friedrichs-Lewy (CFL) number. Two cases, i.e., flat die-workpiece interface and inclined die-workpiece interface, are investigated in the present work. The elastic wave propagation is simulated with a two-dimension (2D) model of the die and workpiece using reflecting boundary conditions for different material properties. The experimental and simulation-based results of reflected and transmitted wave characteristics are compared for different materials in terms of reflected and transmitted wave height ratio and material properties such as acoustic impedance. It is found that the numerical simulation results are in good agreement with the experimental results.

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