LARGE AREA PARALLEL SURFACE NANOSTRUCTURING WITH LASER IRRADIATION THROUGH MICROLENS ARRAYS

2010 ◽  
Vol 17 (03) ◽  
pp. 383-387
Author(s):  
C. S. LIM ◽  
M. H. HONG ◽  
Y. LIN ◽  
L. S. TAN ◽  
A. SENTHIL KUMAR ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Microlens Array ◽  
Laser Pulses ◽  
Polymer Materials ◽  
Direct Writing ◽  
Large Area ◽  
Microlens Arrays ◽  
Force Microscopy ◽  
Surface Nanostructuring ◽  
Parallel Surface

In the past decade, the development of nanoelectronics and nano-optics has attracted much interest in surface nanostructuring of semiconductor materials. The irradiation of a microlens array by a laser beam generates many focused light spots, which can act as a direct writing tool on photo-polymer materials. This maskless surface nanostructuring technique enables thousands to millions of identical nano-features to be patterned in a couple of laser pulses. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images show that nano-features were patterned uniformly on the substrate surface, which suggests a versatile way of parallel surface nanostructuring over a large area. The simulation results of the energy flux distribution at the focal plane of the microlens arrays will also be discussed.

Light Extraction Efficiency Analysis of Phosphorescent OLED Device with Microlens Array on the Glass Substrate

2021 ◽  
Author(s):  
Arvind Sharma ◽  
T. D. Das
Keyword(s):  
Extraction Efficiency ◽  
Substrate Surface ◽  
Computational Simulation ◽  
Microlens Array ◽  
Device Fabrication ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Oled Device ◽  
Emission Layer ◽  
Microlens Arrays

Abstract The Computational simulation is based on the desired packing type of microlens array, either hexagonal or rectangular, onto the planar dual scheme OLED device's light-emitting surface. Both active layers here acted as a phosphorescent emission layer studied to improve device efficiency. The microlens array (MLAs) with hexagonal packing can increase the external quantum efficiency by 35%, which is more than the literature mentioned earlier. It significantly enhances the outcoupling efficiency below the critical angle observation concerning the substrate surface normal. Besides, a broad spectrum is observed with a slight shoulder band around 650 nm in the E.L. (Electroluminance) emission curve. From the CIE x and CIE y index studied, the OLED device connected with either hexagonal or rectangular microlens arrays are more sensitive than the OLED device without microlens arrays to the viewing angle range. The effect of outcoupled efficiency as a function of ETL-TPBi thickness is studied under different polarization modes. Hence, the study suggested that a microlens array with a hexagonal or rectangular packing type on the OLED device's top significantly enhanced light extraction efficiency and provided better device fabrication results.

scholarly journals AFM Study of the Influence of Glycerol Flow on Horseradish Peroxidase near the in/out Linear Sections of a Coil

2021 ◽  
Vol 11 (4) ◽  
pp. 1723
Author(s):  
Yuri D. Ivanov ◽  
Tatyana O. Pleshakova ◽  
Ivan D. Shumov ◽  
Andrey F. Kozlov ◽  
Irina A. Ivanova ◽  
...  
Keyword(s):  
Horseradish Peroxidase ◽  
Enzymatic Activity ◽  
Protein Adsorption ◽  
Substrate Surface ◽  
Control Sample ◽  
Thermal Stabilization ◽  
Heat Transfer Fluid ◽  
Force Microscopy ◽  
Model Protein ◽  
Linear Sections

Flow-based coiled systems, through which a heat transfer fluid (such as glycerol) is pumped, are widely used for thermal stabilization of bioreactors and biosensor cuvettes and cells. Previously, using horseradish peroxidase (HRP) as a model protein, we have demonstrated that the incubation of a protein solution in a flow-based system over coiled pipe with flowing glycerol leads to a change in the adsorption properties of the protein macromolecules. Herein, we have studied the effect of the glycerol flow on the properties of HRP, the solution of which was placed differently: i.e., near either the inflow or the outflow linear sections of the pipe, while the coiled section of the pipe was shielded with a grounded metallic cover. Atomic force microscopy (AFM) has been employed in order to visualize the HRP protein macromolecules adsorbed from its solution onto the mica substrate surface. The quantity of adsorbed protein was estimated based on the AFM data. The enzymatic activity of HRP was estimated by spectrophotometry. We demonstrate that a change in the properties of HRP enzyme was observed after the incubation of its solution near the inflow/outflow linear sections of the pipe with flowing glycerol. Namely, after the incubation of HRP solution near the inflow section, a decrease in the protein adsorption onto mica was observed, but its enzymatic activity remained unchanged in comparison to the control sample. In another case, when the HRP solution was incubated near the outflow section, an increased protein adsorption was observed, while the enzyme exhibited considerably lower activity.

scholarly journals Optical Sensitivity of Waveguides Inscribed in Nanoporous Silicate Framework

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 123
Author(s):  
Zhong Lijing ◽  
Roman A. Zakoldaev ◽  
Maksim M. Sergeev ◽  
Andrey B. Petrov ◽  
Vadim P. Veiko ◽  
...  
Keyword(s):  
Refractive Index ◽  
Near Field ◽  
Experimental Studies ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Direct Writing ◽  
Sensor Applications ◽  
Refractive Index Contrast ◽  
Optical Sensitivity ◽  
Index Contrast

Laser direct writing technique in glass is a powerful tool for various waveguides’ fabrication that highly develop the element base for designing photonic devices. We apply this technique to fabricate waveguides in porous glass (PG). Nanoporous optical materials for the inscription can elevate the sensing ability of such waveguides to higher standards. The waveguides were fabricated by a single-scan approach with femtosecond laser pulses in the densification mode, which resulted in the formation of a core and cladding. Experimental studies revealed three types of waveguides and quantified the refractive index contrast (up to Δn = 1.2·10−2) accompanied with ~1.2 dB/cm insertion losses. The waveguides demonstrated the sensitivity to small objects captured by the nanoporous framework. We noticed that the deposited ethanol molecules (3 µL) on the PG surface influence the waveguide optical properties indicating the penetration of the molecule to its cladding. Continuous monitoring of the output near field intensity distribution allowed us to determine the response time (6 s) of the waveguide buried at 400 µm below the glass surface. We found that the minimum distinguishable change of the refractive index contrast is 2 × 10−4. The results obtained pave the way to consider the waveguides inscribed into PG as primary transducers for sensor applications.

Pattern Writing by Implantation in a Large-Scale PSII System With Planar Inductively Coupled Plasma Source

2000 ◽  
Vol 624 ◽  
Author(s):  
Lingling Wu ◽  
Hongjun Gao ◽  
Dennis M. Manos
Keyword(s):  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Lateral Diffusion ◽  
Plasma Source ◽  
Direct Writing ◽  
Large Area ◽  
Depth Profiles ◽  
Geometric Patterns ◽  
Planar Coil ◽  
Rf Antenna

ABSTRACTA large-scale plasma source immersion ion implantation (PSII) system with planar coil RFI plasma source has been used to study an inkless, deposition-free, mask-based surface conversion patterning as an alternative to direct writing techniques on large-area substrates by implantation. The apparatus has a 0.61 m ID and 0.51 m tall chamber, with a base pressure in the 10−8 Torr range, making it one of the largest PSII presently available. The system uses a 0.43 m ID planar rf antenna to produce dense plasma capable of large-area, uniform materials treatment. Metallic and semiconductor samples have been implanted through masks to produce small geometric patterns of interest for device manufacturing. Si gratings were also implanted to study application to smaller features. Samples are characterized by AES, TEM and variable-angle spectroscopic ellipsometry. Composition depth profiles obtained by AES and VASE are compared. Measured lateral and depth profiles are compared to the mask features to assess lateral diffusion, pattern transfer fidelity, and wall-effects. The paper also presents the results of MAGIC calculations of the flux and angle of ion trajectories through the boundary layer predicting the magnitude of flux as a function of 3-D location on objects in the expanding sheath

Patterning Organic Fluorescent Molecules with SAM Patterns

2011 ◽  
Vol 1335 ◽  
Author(s):  
Qiong Wu ◽  
Juanyuan Hao ◽  
Shoulei Shi ◽  
Weifeng Wang ◽  
Nan Lu
Keyword(s):  
Organic Molecules ◽  
Low Cost ◽  
Substrate Surface ◽  
Large Area ◽  
Self Assembled Monolayer ◽  
Storage Duration ◽  
Light Emitting ◽  
High Throughput Method ◽  
Self Assembled ◽  
Fluorescent Molecules

ABSTRACTWe report a low-cost and high-throughput method to fabricate large-area light emitting pattern via thermal evaporation of organic molecules on the patterned self-assembled monolayer of homogenous 3-aminopropyltrimethoxysilane. This method is based on the selective deposition of the organic light emitting molecules on the template of self-assembled monolayer (SAM), which is patterned with nanoimprinting lithography. The selectivity can be controlled by adjusting the design of the pattern, the storage duration and the substrate temperature. The deposition selectivity of the molecules may be caused by the different binding energy of the molecules with the SAM and the substrate surface.

High power supercontinuum generation by dual-color femtosecond laser pulses in fused silica

2021 ◽  
Author(s):  
Saba Zafar ◽  
Dong-Wei Li ◽  
Acner Camino ◽  
Jun-Wei Chang ◽  
Zuo-Qiang Hao
Keyword(s):  
Femtosecond Laser ◽  
High Power ◽  
Microlens Array ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Fused Silica ◽  
Spectral Energy ◽  
Phase Matching ◽  
Fundamental Wavelength ◽  
Fundamental Laser

Abstract High power supercontinuum (SC) is generated by focusing 800 nm and 400 nm femtosecond laser pulses in fused silica with a microlens array. It is found that the spectrum of the SC is getting broader compared with the case of single laser pulse, and the spectral energy density between the two fundamental laser wavelengths is getting significantly higher by optimizing the phase matching angle of the BBO. It exceeds μJ/nm over 490 nm range which is from 380 nm to 870 nm, overcoming the disadvantage of relative lower power in the ranges far from fundamental wavelength.

Investigation of surface morphology of thin metal films with magnetic layers Fe-Cr-Co

2021 ◽  
Author(s):  
V.S. Zayonchkovsky ◽  
Aung Kyaw Kyaw ◽  
A.V. Andreev
Keyword(s):  
Atomic Force Microscopy ◽  
Magnetron Sputtering ◽  
Electron Microscopic Examination ◽  
Nearest Neighbors ◽  
Substrate Plane ◽  
Large Area ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Large Projection

Films containing layers of dispersion-hardening alloys (LDHA) based on the Fe-Cr-Co system were obtained by magnetron sputtering. LDHA acquire the properties of film permanent magnets after a single-stage «fast» high-vacuum annealing. Bulk materials acquire such properties only after many hours of multi-stage heat treatment. The film samples acquire these properties in tens of seconds. The morphology of their surface was studied to determine the origin of the coercive force of film samples. The surface morphology was studied using high resolution scanning electron microscopy and atomic force microscopy. We studied two compositions that, in bulk, have a different tendency to form many phases during crystallization. In magnetron sputtering, the alloy in which a multiphase state is easily formed is polycrystalline. The antipode alloy in magnetron sputtering is realized in an amorphous state. After annealing, both alloys are in a polycrystalline state. Electron microscopic examination showed that as a result of annealing, crystallites are formed with a large projection onto the substrate plane, which grow due to the nearest neighbors. Moreover, these crystallites have not only a large area, but also a height. After annealing, both alloys are in a polycrystalline state. Electron microscopic examination showed that as a result of annealing, crystallites are formed with a large projection onto the substrate plane, which grow due to the nearest neighbors. Moreover, these crystallites have not only a large area, but also a height. What is determined by atomic force microscopy. High crystallites are also faceted. This may indicate that the composition of these crystallites differs from the composition of the surrounding layer, which may be the reason for the increase in coercive force as a result of annealing.

scholarly journals Growth of Ordered Graphene Ribbons by Sublimation Epitaxy

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 449
Author(s):  
Shuxian Cai ◽  
Xingfang Liu ◽  
Xin Zheng ◽  
Zhonghua Liu
Keyword(s):  
Substrate Surface ◽  
Graphene Film ◽  
Graphene Ribbon ◽  
High Quality ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Few Layer Graphene

Ordered graphene ribbons were grown on the surface of 4° off-axis 4H-SiC wafers by sublimation epitaxy, and characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and micro-Raman spectroscopy (μ-Raman). SEM showed that there were gray and dark ribbons on the substrate surface, and AFM further revealed that these ordered graphene ribbons had clear stepped morphologies due to surface step-bunching. It was shown by μ-Raman that the numbers of graphene layers of these two types of regions were different. The gray region was composed of mono- or bilayer ordered graphene ribbon, while the dark region was of tri- or few-layer ribbon. Meanwhile, ribbons were all homogeneous and had a width up to 40 μm and a length up to 1000 μm, without micro defects such as grain boundaries, ridges, or mono- and few-layer graphene mixtures. The results of this study are useful for optimized growth of high-quality graphene film on silicon carbide crystal.

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