Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Speckle lithography for fabricating Gaussian, quasi-random 2D structures and black silicon structures.

ABSTRACT: Laser speckle pattern is a granular structure formed due to random coherent wavelet interference and generally considered as noise in optical systems including photolithography. Contrary to this, in this paper, we use the speckle pattern to generate predictable and controlled Gaussian random structures and quasi-random structures photo-lithographically. The random structures made using this proposed speckle lithography technique are quantified based on speckle statistics, radial distribution function (RDF) and fast Fourier transform (FFT). The control over the speckle size, density and speckle clustering facilitates the successful fabrication of black silicon with different surface structures. The controllability and tunability of randomness makes this technique a robust method for fabricating predictable 2D Gaussian random structures and black silicon structures. These structures can enhance the light trapping significantly in solar cells and hence enable improved energy harvesting. Further, this technique can enable efficient fabrication of disordered photonic structures and random media based devices.

SUBMITTER: Bingi J

PROVIDER: S-EPMC4683453 | biostudies-other | 2015

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Viscoelastic lithography for fabricating self-organizing soft micro-honeycomb structures with ultra-high aspect ratios.

Project description:High-aspect ratio micro- and nano-structures have been used for the production of a variety of applications. In this paper, we describe a simple and cost-effective approach to fabricate an arrayed microarchitecture with an ultra-high aspect ratio using soft materials. The shapes and sizes of the honeycomb structure can be easily modulated by changing the dimensions and position of the base mould pattern and the pressure. The honeycomb structure is used to prepare a drug delivery patch and a microwell array to form cell spheroids without cell loss. The honeycomb structures prepared using natural ECM (collagen-Matrigel) materials are successfully fabricated. The hepatocytes and endothelial cells are seeded and co-cultured in the ECM-based micro-honeycomb to prepare a 3D liver model successfully mimicking an ultrastructure of liver and providing enhanced liver function.

| S-EPMC4865738 | biostudies-literature

Individual speckle diffraction based 1D and 2D Random Grating Fabrication for detector and solar energy harvesting applications.

Project description:Laser speckles and speckle patterns, which are formed by the random interference of scattered waves from optically rough surfaces, have found tremendous applications in a wide range of metrological and biomedical fields. Here, we demonstrate a novel edge diffraction phenomenon of individual speckle for the fabrication of 1D and 2D micron and sub-micron size random gratings. These random gratings exhibit broadband response with interesting diffusive diffraction patterns. As an immediate application for solar energy harvesting, significant reduction in transmission and enhanced absorption in thin "Si-random grating-Si" sandwich structure is demonstrated. This work has multifaceted significance where we exploited the individual speckle diffraction properties for the first time. Besides the solar harvesting applications, random gratings are suitable structures for fabrication of theoretically proposed random quantum well IR detectors and hence expected that this work will augur well for such studies in the near future.

| S-EPMC4740903 | biostudies-literature

Aggregation-Induced Emission Luminogens Sensitized Quasi-2D Hybrid Perovskites with Unique Photoluminescence and High Stability for Fabricating White Light-Emitting Diodes.

Project description:In order to endow quasi-2D organic-inorganic hybrid metal halide perovskites (quasi-2D-PVK) with superior performance, an aromatic organic ligand with aggregation-induced emission (AIE) features is rationally designed and utilized for constructing distinctive quasi-2D-PVK materials. This AIE-active ligand, TTPy-NH2 , well fits into the lattices of quasi-2D-PVK and leaves hydrophobic tails surrounding PVK layers, making the presented TTPy-NH2 /PVK film extraordinary in terms of both luminescence and stability. Benefiting from the prominent sensitization function and AIE tendency of TTPy-NH2 , the presented TTPy-NH2 /PVK film exhibits a high quantum yield of 62.2%, unique blue-red dual-emission property of both blue and red, high stability with the remnant of more than 94% fluorescence intensity remnant after 21 days. As a result, TTPy-NH2 /PVK film is capable of constituting high-performance white light-emitting diodes, with its color gamut reaching 138% of the National Television System Committee （NTSC） standard and the maximum efficiency is 105 lm W-1 at 20 mA. Evidently, a win-win effect is achieved by the integration of AIE-active ligands and quasi-2D-PVK, which are two of the most reputable solid-state luminogens. This developed protocol thus opens up a new avenue for exploring the next generation of luminescent devices.

| S-EPMC8336619 | biostudies-literature

An Investigation into Hydraulic Permeability of Fibrous Membranes with Nonwoven Random and Quasi-Parallel Structures.

Project description:Fibrous membranes with a nonwoven random structure and a quasi-parallel fibrous structure can be fabricated by the electrospinning technique. The membranes with different structures exhibited different behaviors to a hydraulic flow passing through the membranes. This work presents the effects of the fiber arrangement, fiber diameter, and deformations of the fibers on the hydraulic permeability. The results showed that the hydraulic flow can generate an extrusion pressure which affects the porosity and pore structure of the fibrous membranes. The quasi-parallel fibrous membranes and nonwoven membranes exhibited similar variation tendencies to the change of the experimental variables. However, the quasi-parallel fibrous membranes exhibited a higher sensibility to the change of the hydraulic flow rate. The hydraulic permeability of the quasi-parallel fibrous membranes was further analyzed with packing state models in this work.

| S-EPMC8780038 | biostudies-literature

Patterning 2D materials for devices by mild lithography.

Project description:2D materials have been intensively studied for almost two decades and are now exhibiting exceptional properties. Thus, devices that integrate 2D materials offer many novel functionalities that will contribute significantly to the transition into an era beyond 'Moore'. Lithographic methods are key technologies in the context of materials' integration into devices. However, to fully leverage the capabilities of these potential devices, it is vital to keep the integrity of the 2D materials intact and to minimize damage induced by device processing. This requirement is only partially met when employing conventional lithography methods, as they induce structural defects in the delicate materials. We demonstrate that exposing graphene to typical electron doses used in conventional electron beam lithography induces significant defect formation. The defect density is proportional to the electron dose and the structural integrity cannot be fully recovered by thermal annealing. We introduce a novel approach of mild lithography which combines traditional processing methods with a subsequent transfer step of the patterned mask onto the 2D material. We demonstrate that this separation of pattern definition and pattern application allows the lithographic process to be performed without exposing and potentially damaging the 2D material being processed. Finally, as an example relevant in terms of innovative device architectures, we present how the mild lithography approach can be used to achieve ordered arrangements of gold nanoparticles on 2D materials.

| S-EPMC9041141 | biostudies-literature

Transparent Quasi-Random Structures for Multimodal Light Trapping in Ultrathin Solar Cells with Broad Engineering Tolerance

Project description:Waveguide

| S-EPMC9389614 | biostudies-literature

Lensless Photoluminescence Hyperspectral Camera Employing Random Speckle Patterns.

Project description:We propose and demonstrate a spectrally-resolved photoluminescence imaging setup based on the so-called single pixel camera - a technique of compressive sensing, which enables imaging by using a single-pixel photodetector. The method relies on encoding an image by a series of random patterns. In our approach, the image encoding was maintained via laser speckle patterns generated by an excitation laser beam scattered on a diffusor. By using a spectrometer as the single-pixel detector we attained a realization of a spectrally-resolved photoluminescence camera with unmatched simplicity. We present reconstructed hyperspectral images of several model scenes. We also discuss parameters affecting the imaging quality, such as the correlation degree of speckle patterns, pattern fineness, and number of datapoints. Finally, we compare the presented technique to hyperspectral imaging using sample scanning. The presented method enables photoluminescence imaging for a broad range of coherent excitation sources and detection spectral areas.

| S-EPMC5681664 | biostudies-literature

Silicon surface patterning <i>via</i> galvanic microcontact imprinting lithography.

Project description:Surface patterning without requiring expensive facilities and complex procedures is a major scientific and technological challenge. We report a simple surface patterning strategy on a silicon wafer surface. This strategy, termed galvanic microcontact imprinting lithography (GMIL), is based on the spontaneous galvanic oxidation of silicon due to the electrically coupled silicon/gold mold with lithographically defined patterns. The galvanic induced silicon oxide pattern can be selectively removed in dilute HF solution or serve as a robust etchant resist in alkaline solution, enabling the formation of regular silicon microstructures on the silicon surface, affording an accessible, simple and cheap surface patterning method with no requirement of expensive and sophisticated instrumentation and facilities. These results may open exciting prospects for next-generation low-cost lithographic techniques.

| S-EPMC9034184 | biostudies-literature

OCT Amplitude and Speckle Statistics of Discrete Random Media.

Project description:Speckle, amplitude fluctuations in optical coherence tomography (OCT) images, contains information on sub-resolution structural properties of the imaged sample. Speckle statistics could therefore be utilized in the characterization of biological tissues. However, a rigorous theoretical framework relating OCT speckle statistics to structural tissue properties has yet to be developed. As a first step, we present a theoretical description of OCT speckle, relating the OCT amplitude variance to size and organization for samples of discrete random media (DRM). Starting the calculations from the size and organization of the scattering particles, we analytically find expressions for the OCT amplitude mean, amplitude variance, the backscattering coefficient and the scattering coefficient. We assume fully developed speckle and verify the validity of this assumption by experiments on controlled samples of silica microspheres suspended in water. We show that the OCT amplitude variance is sensitive to sub-resolution changes in size and organization of the scattering particles. Experimentally determined and theoretically calculated optical properties are compared and in good agreement.

| S-EPMC5665955 | biostudies-literature

Micromask Lithography for Cheap and Fast 2D Materials Microstructures Fabrication.

Project description:The fast and precise fabrication of micro-devices based on single flakes of novel 2D materials and stacked heterostructures is vital for exploration of novel functionalities. In this paper, we demonstrate a fast high-resolution contact mask lithography through a simple upgrade of metallographic optical microscope. Suggested kit for the micromask lithography is compact and easily compatible with a glove box, thus being suitable for a wide range of air-unstable materials. The shadow masks could be either ordered commercially or fabricated in a laboratory using a beam lithography. The processes of the mask alignment and the resist exposure take a few minutes and provide a micrometer resolution. With the total price of the kit components around USD 200, our approach would be convenient for laboratories with the limited access to commercial lithographic systems.

| S-EPMC8397995 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data