scholarly journals Multi-Mode Interferometry: Application to TiO2–SiO2 Sol-Gel Waveguide-Based Sensing in the Aerospace Domain

Aerospace ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 401
Author(s):  
Maxime Royon ◽  
Thomas Blanchet ◽  
Muhammad Adnan ◽  
Damien Jamon ◽  
François Royer ◽  
...  
Keyword(s):  
Low Cost ◽  
Sol Gel ◽  
Beam Propagation Method ◽  
Visible Region ◽  
Light Transport ◽  
Device Structure ◽  
Optical Source ◽  
Temperature Changes ◽  
Direct Laser ◽  
Multi Mode

The optimization of a 2D optical sensor based on TiO2–SiO2 sol-gel waveguides for damage detection in the aerospace domain was performed in the framework of the ADD-ON European project. The sensor is based on the transportation of visible light along numerous waveguides, and damage is detected and localized through the monitoring of the output light from the waveguide grid. In this work, we have developed an architecture, inspired by a multi-mode interferometer (MMI), allowing us to efficiently multiply the number of waveguides that can be probed by a single optical source. For this, the beam propagation method (BPM) was used to model a rectangular MMI coupler (40 × 5624 µm2) operating in the visible region (600 nm), ensuring the propagation of light into three waveguides. The conceived device was then manufactured by UV photolithography (direct laser writing technique). The simulations and experimental results show that light transport into this architecture allows for the successful simultaneous probing of three waveguides. By complexifying the device structure, successful MMI couplers were easily manufactured, allowing us to probe 9, 15, or 45 TiO2–SiO2 waveguides with a unique light source. Finally, a further investigation regarding 24 consecutive thermal cycles from −40 °C to 60 °C, representative of the temperature changes during aircraft cruising, was performed. This study reveals that TiO2–SiO2 sol-gel waveguides are not mechanically damaged by temperature changes, while the light guidance remains unaffected, confirming that this sensor is very promising for aerospace applications. Since a single source can monitor several guides, the production of more compact, low-cost, and less intrusive sensors can be achieved by fulfilling structural health monitoring requirements.

scholarly journals Studies on Structural, optical and Magnetic properties of Yttrium Aluminum Bromate (YAB) Nanomaterials, prepared at high annealing temperature

2021 ◽  
Vol 2070 (1) ◽  
pp. 012067
Author(s):  
Bibhuti Bikramaditya ◽  
Rakesh Kumar Singh ◽  
Nishant Kumar ◽  
Pushpendra Kumar Verma
Keyword(s):  
Magnetic Properties ◽  
High Temperature ◽  
Annealing Temperature ◽  
Light Emission ◽  
Low Cost ◽  
Sol Gel ◽  
Visible Region ◽  
Photoluminescence Property ◽  
Photo Luminescence ◽  
Yttrium Aluminum

Abstract In this research, we present structural, photo-luminescence and magnetic properties of the Yttrium Aluminum Borate (YAB) nanomaterial, synthesized by low-cost Sol-gel method in high temperature range. X-ray diffraction (XRD) analysis, shows that crystal structure of YAB is of nanometric size ranging between 38 nm to 47 nm for the annealing temperature above 900°C. Photoluminescence property shows that YAB gives intense Blue light emission in the visible region. High-temperature annealing was found to increase the grain size and enhance the blue luminescence. Vibrating Sample Magnetometer (VSM) shows that coercivity increases while Magnetization and retentivity decreases for YAB nanomaterials for the temperature above 900 degree Celsius. Prepared YAB materials may be useful for LED or related devices.

Photoluminescence of Sol-Gel Synthesized ZnO Nanostructures

2021 ◽  
Vol 885 ◽  
pp. 121-126
Author(s):  
Erasto Vergara Hernández ◽  
Brenda Carolina Pérez Millán ◽  
Yael Valdemar Torres Torres ◽  
César Eduardo Cea Montufar
Keyword(s):  
Optical Properties ◽  
Optical Transition ◽  
Low Cost ◽  
Sol Gel ◽  
Research Work ◽  
Synthesis Method ◽  
Visible Region ◽  
Zno Nanostructures ◽  
Zinc Oxide Nanostructures ◽  
Oxide Nanostructures

Zinc oxide nanostructures have potentially interesting optical properties, which make them candidates for use in applications within the area of optoelectronics; their synthesis can be carried out through low-cost methods, such as sol gel, among many others. In addition, depending on the synthesis method, its shape and size, ZnO nanostructures can present emissions in the ultraviolet (UV) and visible region. By doping with elements such as carbon, silver, copper or some rare earth, for example, erbium, terbium or neodymium, the optical properties of ZnO can be adjusted and controlled to be able to be applied in the production of biosensors, photodetectors and even sensors of white light. In this research work, a review is presented on the nature of the optical transition mechanisms that occur in the ZnO nanostructures synthesized by the sol-gel method.

Soft-chemistry Route to P-I-N Heterostructured Quantum Dot Electroluminescence Device: All Solution-processed Polymer-Inorganic Hybrid QD-EL Device

2006 ◽  
Vol 959 ◽  
Author(s):  
Soon-Jae Kwon ◽  
Kyung-Sang Cho ◽  
Byoung-Lyong Choi ◽  
Byung-Ki Kim
Keyword(s):  
Quantum Dot ◽  
Electronic Band Structure ◽  
Low Cost ◽  
Sol Gel ◽  
Device Structure ◽  
Electronic Band ◽  
Solution Processed ◽  
Turn On ◽  
Ito Glass ◽  
Polymer Semiconductor

ABSTRACTp-i-n heterostructured quantum-dot electroluminescence (QD-EL) device was fabricated by soft-chemical process, which shows a low turn-on voltage comparable to OLEDs. To construct the multilayered device structure, p-type polymer semiconductor was deposited on the ITO glass by sequential process of coating and thermal curing, thereupon a few monolayers of QD was spin-coated. n-type metal-oxide film was deposited on top of the QD luminescence layer by sol-gel method, providing a facile and low-cost route for the ETL fabrication. Prior to solution-processed ETL construction, a post-treatment is performed using cross-linking agent, in order to chemically-immobilize the QDs. As a cathodic electrode, relatively air-stable aluminum was deposited. The constituent material as well as the electronic band structure of the integrated device guarantees operating stability in air and low turn-on voltage.

scholarly journals Excellent Photocatalytic Degradation of Indigo Dye using Low Cost Chemical Route Grown Highly Luminescent SnO2 Decorated Polystyrene Nanocomposites

2021 ◽  
Author(s):  
Jyoti Bala Kaundal ◽  
R.K Tiwari ◽  
Y C Goswami
Keyword(s):  
Polymer Nanocomposites ◽  
Tin Oxide ◽  
Low Cost ◽  
Sol Gel ◽  
Visible Region ◽  
Chemical Route ◽  
Glass Substrates ◽  
Afm Micrographs ◽  
Polystyrene Waste ◽  
Vertical Chain

Abstract Irrational use of dye is a challenge for our environment specifically for clean water. Highly luminescent SnO2 decorated Polystyrene nanocomposites developed as an effective solution for it. The low cost chemical synthesis of highly luminescent tin oxide decorated Polystyrene (SnO2-PS) polymer nanocomposites using recyclable expended polystyrene waste has been reported. Sol gel grown tin oxide nanoparticles, thoroughly dissolved in dissolved in toluene were used with recyclable expended polystyrene waste. The composites were grown either on glass substrates or developed as flexible self sustaining layers and characterized by optical, structural & morphological characterizations. X ray diffractograms of SnO2-PS polymer nanocomposites exhibit crystalline behavior with tetragonal structure of SnO2. Accumulation of SnO2 particles on the surface with increasing concentration, in the form of spherical structures is observed in AFM micrographs. Hollow vertical chain like growth is also observed. Absorption edge shift towards higher wavelength results in decrease in band gap with increasing concentration. The Photoluminescence (PL) spectra for higher SnO2 shows a significant peak peaks in visible spectra at about 425 nm. SnO2 decorated Polystyrene nanocomposites synthesized using recyclable expended polystyrene waste opens a new scope in flexible optoelectronic applications with visible region photoluminescence.

scholarly journals Sol–Gel Waveguide-Based Sensor for Structural Health Monitoring on Large Surfaces in Aerospace Domain

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 109
Author(s):  
Maxime Royon ◽  
Damien Jamon ◽  
Thomas Blanchet ◽  
François Royer ◽  
Francis Vocanson ◽  
...  
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Optical Sensors ◽  
Low Cost ◽  
Sol Gel ◽  
Matrix Structure ◽  
Structural Health ◽  
Photonic Sensor ◽  
Promising Tool ◽  
Direct Laser

The potential of sol–gel-based optical sensors is investigated for applications in the aerospace domain. To this aim, a low-cost and non-intrusive sol–gel sensor based on waveguides, arranged as a 2D matrix structure, is fabricated by UV photolithography for delamination and damage detection. Two different organic–inorganic sol–gels were selected to fabricate the photonic device: TiO2–SiO2 and ZrO2–SiO2, acting as the waveguide core and the cladding, respectively. A systematic study was performed to determine the manufacturing parameters controlling their properties. The results show that large surfaces can be functionalized via sol–gel methods using the direct laser-writing approach. The structures are characterized in terms of refractive index, and the guiding properties were investigated through simulations and experiments, indicating an excellent behavior regarding the light guidance in a straight waveguide or in the 2D matrix structure grid. Additionally, preliminary tests show that the presence of impact can be easily detected after damage through the induced optical losses on large surfaces. This proof of concept sensor is a promising tool for structural health monitoring. To achieve the ultimate goal, the integration of this photonic sensor will be later performed on aircraft wings.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

scholarly journals A simple approach to prepare fluorescent molecularly imprinted nanoparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7732-7737
Author(s):  
Fenying Wang ◽  
Dan Wang ◽  
Tingting Wang ◽  
Yu Jin ◽  
Baoping Ling ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Sol Gel ◽  
Silica Sol ◽  
Simple Approach ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Low Toxicity ◽  
Good Biocompatibility ◽  
Molecularly Imprinted Nanoparticles

Fluorescent molecularly imprinted polymer (FMIP) gains great attention in many fields due to their low cost, good biocompatibility and low toxicity. Here, a high-performance FMIP was prepared based on the autocatalytic silica sol–gel reaction.

scholarly journals Titanium Nitride Nanodonuts Synthesized from Natural Ilmenite Ore as a Novel and Efficient Thermoplasmonic Material

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Thanh-Lieu Thi Le ◽  
Lam Tan Nguyen ◽  
Hoai-Hue Nguyen ◽  
Nguyen Van Nghia ◽  
Nguyen Minh Vuong ◽  
...  
Keyword(s):  
Titanium Nitride ◽  
Low Cost ◽  
Visible Region ◽  
Resonance Absorption ◽  
Solar Light ◽  
Localized Surface Plasmon ◽  
Water Evaporation ◽  
Energy Applications ◽  
Simulated Solar Light ◽  
New Class

Nanostructures of titanium nitride (TiN) have recently been considered as a new class of plasmonic materials that have been utilized in many solar energy applications. This work presents the synthesis of a novel nanostructure of TiN that has a nanodonut shape from natural ilmenite ore using a low-cost and bulk method. The TiN nanodonuts exhibit strong and spectrally broad localized surface plasmon resonance absorption in the visible region centered at 560 nm, which is well suited for thermoplasmonic applications as a nanoscale heat source. The heat generation is investigated by water evaporation experiments under simulated solar light, demonstrating excellent solar light harvesting performance of the nanodonut structure.

scholarly journals Synthesis and characterization of Mg–Zn ferrite based flexible microwave composites and its application as SNG metamaterial

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Atiqur Rahman ◽  
Mohammad Tariqul Islam ◽  
Mandeep Singh Jit Singh ◽  
Md Samsuzzaman ◽  
Muhammad E. H. Chowdhury
Keyword(s):  
Low Cost ◽  
Sol Gel ◽  
Microwave Frequency ◽  
Dielectric Substrate ◽  
Dielectric Constants ◽  
Potential Candidate ◽  
Flexible Composites ◽  
Average Grain Size ◽  
Zn Ferrite ◽  
High Flexibility

AbstractIn this article, we propose SNG (single negative) metamaterial fabricated on Mg–Zn ferrite-based flexible microwave composites. Firstly, the flexible composites are synthesized by the sol-gel method having four different molecular compositions of MgxZn(1−x)Fe2O4, which are denoted as Mg20, Mg40, Mg60, and Mg80. The structural, morphological, and microwave properties of the synthesized flexible composites are analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and conventional dielectric assessment kit (DAK) to justify their possible application as dielectric substrate at microwave frequency regime. Thus the average grain size is found from 20 to 24 nm, and the dielectric constants are 6.01, 5.10, 4.19, and 3.28, as well as loss tangents, are 0.002, 0.004, 0.006, and 0.008 for the prepared Mg–Zn ferrites, i.e., Mg20, Mg40, Mg60, and Mg80 respectively. Besides, the prepared low-cost Mg–Zn ferrite composites exhibit high flexibility and lightweight, which makes them a potential candidate as a metamaterial substrate. Furthermore, a single negative (SNG) metamaterial unit cell is fabricated on the prepared, flexible microwave composites, and their essential electromagnetic behaviors are observed. Very good effective medium ratios (EMR) vales are obtained from 14.65 to 18.47, which ensure the compactness of the fabricated prototypes with a physical dimension of 8 × 6.5 mm2. Also, the proposed materials have shown better performances comparing with conventional FR4 and RO4533 materials, and they have covered S-, C-, X-, Ku-, and K-band of microwave frequency region. Thus, the prepared, flexible SNG metamaterials on MgxZn(1−x)Fe2O4 composites are suitable for microwave and flexible technologies.

scholarly journals Green Synthesis of N/Zr Co-Doped TiO2 for Photocatalytic Degradation of p-Nitrophenol in Wastewater

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Visible Region ◽  
Chemical Properties ◽  
Pure Tio2 ◽  
Molar Ratio ◽  
Xps Spectra ◽  
Doped Tio2 ◽  
Co Doped

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.

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