Silica Layer Research Articles

High-Directionality Silicon Nitride Antenna Based on Distributed Bragg Reflector for Optical Phased Array

Optical phased arrays (OPAs) have great potential in the fields of integrated solid-state light detection and ranging. The ranging distance of an OPA can be further enlarged by improving the directionality of the grating antenna. A high-directionality silicon nitride grating antenna with a distributed Bragg reflector (DBR) is proposed. The DBR consists of a stack of silicon nitride and silicon dioxide layers, which are utilized as the bottom reflectors to further reduce downward radiation. In a simulation, the directionality of the antenna exceeded 71.6% within the wavelength range of 1420–1740 nm. Additionally, the directionality of the antenna can achieve 97.6% at 1550 nm. Compared to a grating antenna without a DBR, the directionality is improved by 1.52 dB. Moreover, the proposed silicon nitride grating antenna has a large fabrication tolerance and is compatible with CMOS fabrication techniques, showing great potential for enhancing the performance of the integrated optical phased array.

Formation of structured silica layers from Dodecaphenyl POSS thin films via microwave-induced oxygen plasma treatment

The study investigated the effect of microwave-induced oxygen plasma on Dodecaphenyl-POSS (Ph12T12) thin films that were obtained by Physical Vapor Deposition (PVD) in an Ultra-High Vacuum (UHV) system. Due to its ability to self-assemble and its relatively low cost, Ph12T12 is a promising material as a precursor for the fabrication of silica thin films. The study found that the treatment of the Ph12T12 thin film with oxygen plasma results in the formation of a new material with a cage-like structure preserved. The thin films were examined using X-ray Reflectivity (XRR), Raman spectroscopy, and Atomic Force Microscopy (AFM). The results showed significant changes in the microstructure, chemical composition, and topography of the annealed POSS films. Thermal and plasma treatment improved the thermal resistance of the surface layer, increasing the evaporation temperature by over 80 °C. XRR modeling of the films' spectra enabled the determination of the composition of each interphase. Additionally, Bragg reflections (00l) remained visible on the spectra after annealing, indicating the presence of a preserved POSS cage-like structure.

Using Vertically Aligned Carbon Nanofiber Arrays on Rigid or Flexible Substrates for Delivery of Biomolecules and Dyes to Plants.

The delivery of biomolecules and impermeable dyes to intact plants is a major challenge. Nanomaterials are up-and-coming tools for the delivery of DNA to plants. As exciting as these new tools are, they have yet to be widely applied. Nanomaterials fabricated on rigid substrate (backing) are particularly difficult to successfully apply to curved plant structures. This study describes the process for microfabricating vertically aligned carbon nanofiber arrays and transferring them from a rigid to a flexible substrate. We detail and demonstrate how these fibers (on either rigid or flexible substrates) can be used for transient transformation or dye (e.g., fluorescein) delivery to plants. We show how VACNFs can be transferred from rigid silicon substrate to a flexible SU-8 epoxy substrate to form flexible VACNF arrays. To overcome the hydrophobic nature of SU-8, fibers in the flexible film were coated with a thin silicon oxide layer (2-3 nm). To use these fibers for delivery to curved plant organs, we deposit a 1 µL droplet of dye or DNA solution on the fiber side of VACNF films, wait 10 min, place the films on the plant organ and employ a swab with a rolling motion to drive fibers into plant cells. With this method, we have achieved dye and DNA delivery in plant organs with curved surfaces.

Ultra-narrowband, electrically switchable, and high-efficiency absorption in monolayer graphene resulting from lattice plasmon resonance

We propose a novel approach to obtain the ultra-narrowband, electrically switchable, and high-efficiency absorption in the monolayer graphene. The monolayer graphene is sandwiched between the silica substrate and a square array of silver nanospheres, which is covered by a very thick silica layer. The fundamental role of the thick silica cover layer is to homogenize the surrounding medium of the silver nanospheres, and thus efficiently exciting the lattice plasmon resonance. The lattice plasmon resonance arising from the coupling between the dipolar plasmon resonance of silver nanospheres and the zero-order diffraction wave at Wood anomaly can enhance the electromagnetic fields at the graphene surface, and thus greatly improve the near-infrared light absorption of the monolayer graphene with the maximum absorption efficiency up to 45%. Owing to the low radiation loss of the lattice plasmon resonance, the absorption linewidth of the monolayer graphene can be largely compressed to only several nanometers (3.2 nm ∼ 7.4 nm). Moreover, the absorption of the monolayer graphene in our proposed nanostructures has a nearly 100% modulation depth to exhibit an excellent switching property. Our work will be helpful for some graphene-based photoelectric devices.

Interfaces in reinforced epoxy resins: from molecular scale understanding towards mechanical properties

ContextWe report on atomic level of detail analyses of polymer composite models featuring epoxy resin interfaces to silica, iron oxide, and cellulose layers. Using “reactive” molecular dynamics simulations to explore epoxy network formation, resin hardening is investigated in an unprejudiced manner. This allows the detailed characterization of salt-bridges and hydrogen bonds at the interfaces. Moreover, our sandwich-type composite systems are subjected to tensile testing along the interface normal. To elucidate the role of relaxation processes, we contrast (i) direct dissociation of the epoxy-metal oxide/cellulose contact layer, (ii) constant strain-rate molecular dynamics studies featuring (visco-)elastic deformation and bond rupture of the epoxy resin, and (iii) extrapolated relaxation dynamics mimicking quasi-static conditions. While the fracture mechanism is clearly identified as interface dissociation of the composite constituents, we still find damaging of the nearby polymer phase. The observed plastic deformation and local cavitation are rationalized from the comparably large stress required for the dissociation of salt-bridges, hydrogen bonds, and van der Waals contacts. Indeed, the delamination of the contact layers of epoxy resins with slabs of silica, magnetite, and cellulose call for a maximum stress of 33, 26, and 21 MPa, respectively, as compared to 84 MPa required for bulk epoxy yielding.MethodsMolecular dynamics simulations using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) code were augmented by a Monte Carlo–type procedure to probe epoxy bond formation (Macromolecules 53(22): 9698–9705). The underlying interaction models are split into conventional Generalized Amber Force Fields (GAFF) for non-reacting moieties and a recently developed reactive molecular mechanics potential enabling epoxy bond formation and cleavage (ACS Polymers Au 1(3): 165–174).

Fabrication of Composite Gel Electrolyte and F-Doping Carbon/Silica Anode from Electro-Spun P(VDF-HFP)/Silica Composite Nanofiber Film for Advanced Lithium-Ion Batteries.

The aim of this work is to effectively combine the advantages of polymer and ceramic nanoparticles and improve the comprehensive performance of lithium-ion batteries (LIBs) diaphragm. A flexible film composed of electro-spun P(VDF-HFP) nanofibers covered by a layer of mesoporous silica (P(VDF-HFP)@SiO2) was synthesized via a sol-gel transcription method, then used as a scaffold to absorb organic electrolyte to make gel a electrolyte membrane (P(VDF-HFP)@SiO2-GE) for LIBs. The P(VDF-HFP)@SiO2-GE presents high electrolyte uptake (~1000 wt%), thermal stability (up to ~350 °C), ionic conductivity (~2.6 mS cm-1 at room temperature), and excellent compatibility with an active Li metal anode. Meanwhile, F-doping carbon/silica composite nanofibers (F-C@SiO2) were also produced by carbonizing the P(VDF-HFP)@SiO2 film under Ar and used to make an electrode. The assembled F-C@SiO2|P(VDF-HFP)@SiO2-GE|Li half-cell showed long-cycle stability and a higher discharge specific capacity (340 mAh g-1) than F-C@SiO2|Celgard 2325|Li half-cell (175 mAh g-1) at a current density of 0.2 A g-1 after 300 cycles, indicating a new way for designing and fabricating safer high-performance LIBs.

Facile In-Situ photocatalytic reduction of AuNPs on multilayer Core-Shell Fe3O4@SiO2@PDA magnetic nanostructures and their SERS application

Surface-enhanced Raman scattering (SERS) is a promising analytical technique for the rapid, sensitive, and repeatable detection in various SERS application fields. Herein, a new type of potential magnetically recyclable SERS substrate was designed and rapidly synthesized via a facile three-step template method. First, the magnetic ferroferric oxide (Fe3O4) cores were prepared by a convenient solvothermal approach, and coated with a thin layer of silica by a sol–gel process in order to improve their stability in complicated environments. Next, the negatively charged polydopamine (PDA)/K6[SiW11VIVO40]·7H2O (PDA/SiW11V) outer shell was assembled upon the magnetic Fe3O4@SiO2 core–shell nanoparticles via a layer-by-layer sequential adsorption process using the stickiness of PDA. The SiW11V multilayer shell can be used as the subsequent photocatalytic reduction precursors for the in-situ loading of high-density gold nanoparticles (AuNPs), without any other organic additives. The AuNPs decorated multilayer core–shell Fe3O4@SiO2@PDA magnetic nanostructures were employed as a potential magnetically recyclable SERS substrate, and showed excellent SERS performance. Using crystal violet (CV) as a model target, the as-fabricated AuNPs modified multilayer core–shell Fe3O4@SiO2@PDA magnetic nanostructures SERS substrates exhibited significant enhancement, and pushed the detection limit down to 10-12 M. Aside from the ultrahigh sensitivity, these SERS substrates also possess an excellent reproducibility (relative standard deviation (RSD) ∼ 8.3%), long-term stability (75 days), and unique chemical stability capability in different organic solvents and different environments with pH ≤ 10. Furthermore, a real-life application is also performed by the detection of melamine in spiked milk solution using the as-prepared magnetic nanostructures SERS-active substrates (limit of detection (LOD), 10-8 M). These results highlight that the rational design and controllable synthesis of multifunctional magnetic SERS substrates is a promising strategy in many different application fields such as biosensing, photoelectrocatalysis, and medical diagnosis.

Facile fabrication of robust superhydrophobic polyurethane sponge modified with polydopamine- silica nanoparticle for effective oil/water separation

Porous superhydrophobic materials with high mechanical stability have a significant amount of potential for oil-water separation in practice. In this study, a superhydrophobic material with strong hydrophobic coating adhesion was developed using a polyurethane sponge. The interior and exterior surfaces of the porous polyurethane material were coated using a two-step technique. The sponge was treated with poly (dopamine) to modify its skeleton, allowing the second layer to adhere readily. The second layer of silica applied to the surface of the sponge functions as a superhydrophobic layer. The modified sponge's water contact angle was approximately 156.2° ± 5°, compared to 78° ±2° for the original sponge, demonstrating its superhydrophobic nature. The fabricated sponge is capable of separating and absorbing 43.3–51 times of its initial mass from an oil-water mixture, depending on the type of oil used in the test. Fifteen cycles of oil-water separation were followed by chemical cleaning of the hydrophobic sponge. After undergoing these cycles, the hydrophobic nature and absorption capacity of the produced sponge were preserved. Over a broad pH range, the hydrophobicity of the superhydrophobic sponge was studied, and the results indicated that hydrophobicity was substantially maintained even under harsh pH operating conditions. The water contact angle of the sponge was measured to be 145° ± 1° and 140° ± 1°, respectively, after 12 h of immersion in strong acids and bases.

Magnetic nanosorbents of γ-polyglutamic acid for removing a β-blocker from water

Metoprolol is known as one of the most frequently used β-blockers to treat hypertension, however due to its widespread use and resistance to hydrolysis, concerning amounts of this medicine are found in surface waters, causing negative impacts on the environment and human health. To date, very few water treatment plants remove metoprolol due to the ineffectiveness of conventional procedures, thus indicating the need for more efficient water treatments for eliminating traces of this drug from aqueous wastes. A promising strategy is the development of magnetic assisted sorbents with a high surface area and adequate chemical modification aimed at the target pollutant, offering the possibility of total removal from water supplies and thus limiting potential environmental impacts. In this context, the purpose of this work was to investigate the application of magnetic Fe3O4 nanoparticles coated with silica and γ-polyglutamic acid to capture metoprolol dissolved in water. The synthesized sorbents consisted of magnetite nanoparticles with an average size of 55.8 nm, coated with a layer of amorphous silica covalently bound to γ-polyglutamic acid, thus exposing carboxylate surface active sites, which favor electrostatic interactions with metoprolol. As the γ-polyglutamic acid sources, two types of materials with distinct amounts in the biopolymer (30% and 92%) have been investigated. The adsorption of metoprolol by the nanosorbents γ-PGA/Fe3O4 was evaluated by means of adsorption isotherms and theoretical adsorption models. Freundlich and Langmuir models provide an accurate description of the isotherm, and the compound’s maximum adsorption capacity was 571.6 mg g−1. Noteworthy, the magnetic nanosorbents prepared using γ-polyglutamic acid 30% and 92% have shown comparable performances, which makes this process also economically attractive considering that a low-cost raw material can be used.

Design of a new 2-channel demultiplexer based on Photonic Crystal Fiber

As miniaturization becomes a critical need in many integrated applications, various researchers have primarily focused on creating optical systems and components based on photonic crystal fiber during the past few decades. This article describes a brand-new 1x2 power demultiplexer idea using photonic crystal fiber as a basis. The luminous connection between the center core and coherent laser sources is made possible by inserting defects in the structure of the photonic crystal fiber (PCF) to change the silica and air index. Simulation results will show that two optical signals, 1.46 µm and 1.48 µm, at the input of a PCF structure can be separated into two parts at the output. The novel design controls the direction of light propagation between layers by swapping various air-hole locations using pure silica layers along the length of the fiber. In optical systemic communications, wavelength demultiplexers are crucial components. They act as data distributors and generate several outputs with a single input. This article aims to propose a novel structure with the best performance by introducing flaws in the structure to guide light according to the desired path and demultiplex our signals. By employing a DWDM system, this device may help increase the data bitrate.

EXTRAORDINARY MAGNETORESISTANCE OF LASERANNEALED NANO BORON DEPOSITEDON OXIDIZED POROUS SILICON

This study explores the impact of laser annealing on the electrical and magnetic properties of nano boron deposited on oxidized porous silicon (n-B/PSiO2) and its potential for spintronic applications. The Nd: YAG laser was used at varying energies to anneal the n-B thin films. Increasing the laser energy increased grain size and more ordered grain structures. It also increased surface roughness due to forming new grain boundaries and secondary phases. The electrical properties of the material were also affected by the laser annealing, with an increase in forward and reverse current and an increase in electrical resistivity with increased annealing temperature. The study also found that the magnetoresistance of the material increased with increasing laser temperature, attributed to tunnel injection through the thin silicon dioxide layer, and could be up to 7 times higher than non-annealed n-B/PSiO2in a magnetic field. The study highlights the importance of controlling materials’ grain size and structure for their physical and electrical properties. In addition, it provides insights into the electronic properties of n-B/PSiO2and the behavior of charge carriers in a magnetic field.

Plasmon- and Waveguide-Coupled Fluorescence at the Ultraviolet Region.

Surface plasmon-coupled emission (SPCE) has been well studied for its coupled, directional, and enhanced P-polarized radiation due to the interactions of fluorophores with surface plasmon polaritons (SPPs) on thin metal films. Such surface plasmon polariton-assisted directional fluorescence has various applications in biosensing. Herein, we demonstrate 2-aminopurine (2AP, a UV-absorbing and -emitting fluorophore) emission coupling to modes in aluminum-based plasmon-coupled waveguides (Al-PCWs). Directional emission from 2-aminopurine on plasmon-coupled waveguides was observed at specific angles as P-polarized SPCE and/or as P- or S-polarized waveguide-coupled emission (WGCE). All S-polarized waveguide modes showed clear angularly resolved emission as compared to that of P-polarized surface plasmon-coupled emission or P-polarized waveguide-coupled emission. The coupling angles, efficiencies, and polarizations of the modes were sensitive to the optical properties and overall dimensions of the top dielectric layer in PCWs. The effective plasmon-coupled waveguide can consist of either a thin probe-containing layer on top of the undoped silica film, or a single dielectric PVA layer with probes distributed throughout the film on the Al layer. The former structures with probes confined to the top of the undoped silica layer showed much higher angular resolutions and coupling efficiencies, as well as mode-dependent changes in lifetimes. These results demonstrate that the plasmon and waveguide modes can be used for selective detection of surface-bound and bulk fluorophores, simultaneously.

Designed Multifunctional Spider Silk Enabled by Genetically Encoded Click Chemistry

AbstractSpider silk is recognized for its exceptional mechanical properties and biocompatibility, making it a versatile platform for developing functional materials. In this study, a modular functionalization strategy for recombinant spider silk is presented using SpyTag/SpyCatcher chemistry, a prototype of genetically encoded click chemistry. The approach involves AlphaFold2‐aided design of SpyTagged spider silk coupled with bacterial expression and biomimetic spinning, enabling the decoration of silk with various SpyCatcher‐fusion motifs, such as fluorescent proteins, enzymes, and cell‐binding ligands. The silk threads can be coated with a silica layer using silicatein, an enzyme for silicification, resulting in a hybrid inorganic–organic 1D material. The threads installed with RGD or laminin cell‐binding ligands lead to enhanced endothelial cell attachment and proliferation. These findings demonstrate a straightforward yet powerful approach to 1D protein materials.

Multi-channel terahertz focused beam generator based on shared-aperture metasurface

Most of existing metasurfaces usually have limited channel behavior, which seriouslyhinders their development and application. In this paper, we propose a multi-channel terahertz focused beam generator based on shared-aperture metasurface, and the generator consists of a top square metal strip, a middle layer of silica and a metal bottom plate. By changing the position and size of the shared-aperture array, the designed metasurface can generate any number of multi-channel focusing beams at different predicted positions. In addition, the energy intensity of focusing beams can be controlled. The full-wave simulation results show that the metasurface achieves four-channel vortex focused beam generation with different topological charges, and five-, six-, eight-channel focused beam generation with different energy intensities at a frequency of 1 THz, which are in good agreement with the theoretically calculated predictions. This work can provide a new idea for designing the terahertz multichannel devices.

Intense green upconversion in core-shell structured NaYF4:Er,Yb@SiO2 microparticles for anti-counterfeiting printing

Rare-earth-doped NaYF4 nanoparticles are considered crucial upconversion luminescent materials with many applications, including anti-counterfeiting printing, biological imaging, and optical information storage. This work presents progress in obtaining hydrophilic pigments based on NaYF4:Er,Yb@SiO2 nanoparticles, and their utilization in water-based ink printing for anti-counterfeiting applications. Coating NaYF4:Yb/Er microparticles with SiO2 shells can provide several benefits for printing purposes, such as improved stability, dispersion, and ease of printing. The hydrophilic core-shell structured β-NaYF4:Er, Yb@SiO2 microparticles were successfully prepared using the hydrothermal synthesis and sol-gel Stober method. The obtained microparticles were characterized by Scanning Electron Microscopy, X-ray diffraction, and Energy-dispersive X-ray spectroscopy. Such characterizations confirm that the Er3+ and Yb3+ ions are incorporated in NaYF4 cores, the NaYF4:Er, Yb cores are in hundreds of nanometer sizes, and the NaYF4:Er, Yb microparticles are coated by a silica layer of 50 nm thick. Both NaYF4:Er, Yb and NaYF4:Er, Yb@SiO2 behave as up-conversion luminescent microparticles for both green and red emissions. The CIE chromaticity coordinates indicate that both the nanoparticles have their greenish color under excitation at 980 nm. Although decorating the NaYF4:Er, Yb nanoparticles with the SiO2 shell decreases luminescent intensity (by a factor of 2), this step is still necessary to achieve hydrophilic surfaces for preparing water-based printing inks. Using the synthesized NaYF4:Er, Yb@SiO2 as a pigment, a new water-based ink formula was created based on Polyamide as a polymer matrix. The obtained ink is printable on paper and on transparent and flexible Polyethylene substrate. The printed patterns with a height of 2 cm and a width of 2.5 cm were observed clearly under the irradiation of a 980 nm LED. Their durability in terms of sharpness and color was also assessed after six months.

Silver-Decorated and Silica-Capped Magnetite Nanoparticles with Effective Antibacterial Activity and Reusability.

Fruits are safe, toxin-free, and biomolecule-rich raw materials that may be utilized to decrease metal ions and stabilize nanoparticles. Here, we demonstrate the green synthesis of magnetite nanoparticles which were first capped with a layer of silica, followed by the decoration of silver nanoparticles, termed Ag@SiO2@Fe3O4, by using lemon fruit extract as the reducing agent in a size range of ∼90 nm. The effect of the green stabilizer on the characteristics of nanoparticles was examined via different spectroscopy techniques, and the elemental composition of the multilayer-coated structures was verified. The saturation magnetization of bare Fe3O4 nanoparticles at room temperature was recorded as 78.5 emu/g, whereas it decreased to 56.4 and 43.8 emu/g for silica coating and subsequent decoration with silver nanoparticles. All nanoparticles displayed superparamagnetic behavior with almost zero coercivity. While magnetization decreased with further coating processes, the specific surface area increased with silica coating from 67 to 180 m2 g-1 and decreased after the addition of silver and reached 98 m2 g-1, which can be explained by the organization of silver nanoparticles in an island-like model. Zeta potential values also decreased from -18 to -34 mV with coating, indicating an enhanced stabilization effect of the addition of silica and silver. The antibacterial tests against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) revealed that the bare Fe3O4 and SiO2@Fe3O4 did not show sufficient effect, while Ag@SiO2@Fe3O4, even at low concentrations (≤ 200 μg/mL), displayed high antibacterial activity due to the existence of silver atoms on the surface of nanoparticles. Furthermore, the in vitro cytotoxicity assay revealed that Ag@SiO2@Fe3O4 nanoparticles were not toxic to HSF-1184 cells at 200 μg/mL concentration. Antibacterial activity during consecutive magnetic separation and recycling steps was also investigated, and nanoparticles offered a high antibacterial effect for more than 10 cycles of recycling, making them potentially useful in biomedical fields.

Magnetic nanoadsorbent functionalized with aminophosphonic acid for NdIII ion extraction from aqueous media

The adsorption performance of a new magnetic nanoadsorbent of Nd3+ was investigated. First, the nanoadsorbent was synthesized by chemical coprecipitation, and covered with a silica layer by the sol–gel method to obtain the silica-coated magnetic nanoparticles (MNP@SiO2). Subsequently, it was functionalized with nitrilotris(methylene)triphosphonic acid(NTMP), obtaining the goal aminophosphonic-functionalized nanoadsorbent (MNP@SiO2-NTMP). The functionalized nanoadsorbent was characterized using TEM, XRD, VSM, TGA, ATR-FTIR, EDS, and zeta potential measurements, confirming its nanoscale size, superparamagnetic behavior, and the presence of surface amino-phosphonic groups. The influence of different operational parameters on neodymium adsorption was investigated. The highest adsorption capacity of neodymium(III) was approximately 18 mg·g−1 at pH 6.8, using an adsorbent dose of 1 g·L-1, a neodymium concentration of 100 mg·L-1, and a contact time of 15 min at room temperature. The neodymium(III) adsorption onto MNP@SiO2-NTMP followed a pseudosecond-order model, suggesting chemisorption mechanisms as the rate-limiting step. Batch experimental results showed that Nd3+ adsorption onto MNP@SiO2-NTMP was independent of the ionic strength, indicating the formation of inner-sphere surface complexes.Furthermore, the adsorption thermodynamic analyses suggested that neodymium adsorption was exothermic, entropy decreasing, and more favorable at low temperatures. The best adsorbent regeneration and neodymium desorption from the loaded adsorbent was achieved using acidic solutions of H2SO4, exhibiting excellent adsorbent reusability throughout the four adsorption–desorption cycles. The MNP@SiO2-NTMP was an effective adsorbent material for extracting neodymium(III) from dilute aqueous solutions. Therefore, it is expected that MNP@SiO2-NTMP can potentially be used in more sustainable recovery methods of neodymium from secondary sources, for example, from leaching solutions of NdFeB magnet scraps.

Enhancement of lossy mode resonance sensing properties by the introduction of an intermediate low-refractive-index layer.

Devices based on the lossy mode resonance (LMR) effect have found numerous sensing applications. Herein, the enhancement of the sensing properties by the introduction of an intermediate layer between the substrate and the LMR-supporting film is discussed. Experimental results for a silicon oxide (SiO2) layer of tuned thickness between a glass slide substrate and a thin film of titanium oxide (TiO2) prove the possibility of significantly increasing the LMR depth and the figure of merit (FoM) for refractive index sensing applications, which is supported by a numerical analysis using the plane wave method for a one-dimensional multilayer waveguide. The application of the intermediate layer allows the introduction of a new, to the best of our knowledge, degree of freedom into the design of LMR-based sensors, resulting in improved performance for demanding fields such as chemical sensing or biosensing.

P‐3: Conductive Indium‐Tin‐Zinc Oxide Formed Using an Oxygen Plasma Treatment Through a Silicon Oxide Cover Layer

Indium‐tin‐zinc oxide (ITZO) covered with a silicon oxide layer can be made conductive when subjected to an oxygen plasma treatment. The resulting resistivity is sensitive to the thickness of the cover oxide, the plasma excitation power, and the treatment time. With 280 nm of cover oxide and 10 mins of treatment, the lowest resistivity achieved is 1.2 mΩ∙cm in a plasma biased with a radio frequency excitation power of 100 W and an inductively coupled plasma excitation power of 2000 W. The treatment has been deployed to form the source/drain regions of a self‐aligned, top‐gate ITZO thin‐film transistor.

Preparation of SiO2:TiO2 for High-Performance Double Layer Anti-Reflection Coating

In this work, an anti-reflection coating was prepared in the region (400-1000) nm of wavelength, with a double layer of silicon dioxide (SiO2) as an inner layer and the second layer of the mixture (SiO2) and titanium dioxide (TiO2) with certain ratios, as an outer layer using the chemical spraying method with a number of 6 sprays of layer SiO2 and 12 sprays of layer SiO2 - TiO2. Using the method of chemical spraying deposited on the glass as a substrate with a different number of sprays of SiO2, and a fixed number of TiO2-SiO2. The optical and structural properties were determined using UV-Vis spectroscopy and atomic force microscopy (AFM). The results show that by using a mixed layer, the optimal optical performance of a broadband low-reflection ARC (anti-reflection coating) was obtained. The work also reports the comparison of experimental and theoretical results with the help of MATLAB, which relies on the characteristic matrix along the visible region – near-infrared.