Papers by Keyword: Transparent

Abstract: In this work, solution combustion processed titanium, zinc co-doped indium oxide high transparent semiconducting thin films were demonstrated at annealing temperatures of 300, 350 °C. In the process, low-temperature combustion at 123 °C was verified through thermogravimetric analysis; acetylacetone, 2-methoxyethanol served as fuel and solvent respectively in the redox reaction. Indium titanium zinc oxide (ITiZO) films were developed on glass substrates by spin coating followed by annealing at different temperatures. ITiZO films, powder exhibited high crystallinity exactly matching with indium oxide peaks without forming secondary phases. But, the presence of In, Ti, Zn, and O is clearly visible on film through energy dispersive spectroscopy. Films had transparency more than 85% in the visible range with optical band gap ranging 3.8-3.9 eV. These ITiZO films with smooth and low roughness ranging 0.46-0.5 nm, can have a potential application as an active layer in transparent thin film transistors and optoelectronic devices.

Abstract: The objective of this project was to develop the hydrophobic film for self-cleaning glasses. The effects of octyltriethoxysilane (OTES) additions to hydrolysis of tetraethylorthosilicate (TEOS) on hydrophobic and optically transparent properties were studied. The film was prepared by sol-gel method from the precursors namely, TESO, OTES, isopropanol alcohol (IPA), and deionized water (DI). The sols for coating were obtained with TEOS/OTES ratio of 50:50 to 99:1. The sols were deposited on a commercial glass and dried at 60oC for an hour. After drying, the film properties were characterized by fourier transform infrared spectroscopy (FTIR), UV-VIS Spectrophotometer, x-Ray Diffractometer (XRD), atomic force microscope (AFM), optical microscopy and contact angle meter. It was found that contact angles of the hybrid films increased with the OTES addition, reaching a maximum at 10 wt.%, and the contact angle values were the same as for further addition. The light transmittance was rather stable with increasing amounts of OTES. For the optimized condition, the water contact angle of 108o and light transmittance of 91%, was obtained with TEOS/OTES ratio of 90:10.

Abstract: This work aims to study the effect of SiO₂ and heat treatment temperature in TEOS-SiO₂-OTES film on the hydrophobic property and weathering durability. TEOS-SiO₂-OTES film was prepared by sol-gel process. Tetraethylorthosilicte (TEOS) and Octyltriethoxysilane (OTES) were used to form the gel. The contents of SiO₂ were varied at 0.5% 1% 3% 5% and 10% by weight. The film was deposited on a glass slide by spin coating. The hydrophobic property was studied by FTIR, UV-VIS spectroscopy, SEM, XRD and contact angle. The weathering chamber was used for studying weathering durability. The weathering condition was controlled at 50 oC and 85%RH. Moreover, the chemical resistant was also tested. The study showed that the silica contents affected the surface roughness of film. The surface roughness of film decreased with increasing amounts of SiO₂.

Abstract: Ultraviolet photodetectors (PDs) based on low-dimensional (LD) gallium oxide nanofibers were synthesized and assembled by a low cost and scalable electrospinning method. Highly uniaxially aligned nanofibers were used to assemble photodetectors. Photoconductive investigations indicate that the prepared photodetectors (PDs) are highly sensitive to ultraviolet (UV) light. The prepared photodetectors have shown a high photosensitivity (10³), fast photoresponse, excellent stability, and reproducibility under the illumination of UV light 254 nm. These electrospun nanofibers have also shown a high transparency (<85%) in the visible light 400-700 nm range. The high transparency of these nanobelts demonstrates their use for invisible UV photosensors.

Abstract: Transparent glass ceramics containing Na_3.6Y_1.8(PO₄)₃ crystals were successfully synthesized using high temperature melting quenching and subsequent heat treatment of the precursor glass with a composition 15Na₂CO₃-3Y₂O₃-45SiO₂-31H₃BO₃- 5.4P₂O₅-0.6Sb₂O₃ (mol%). The impact of heat treatment is investigated in detail. The glass sample was tested by differential scanning calorimetry analysis to determine the heat treatment system. The ideal heat-treated condition is at 650°C for 2 h. The structure and morphology properties were systematically analyzed by recording X-ray diffraction patterns and scanning electron microscopy images, which indicate that Na_3.6Y_1.8(PO₄)₃ crystal were precipitated homogeneously among the glass matrix. The microstructural of precursor glass and glass ceramic were compared by analyzing FTIR spectra, indicating the formation of phosphate groups in glass ceramic. The refractive index of glass ceramics samples were measured. In the visible region, the transmittance of glass ceramics is up to 85%. Moreover, the relationship between the refractive index of the sample and the transmittance is discussed.

Abstract: A broadband multi-layer radar absorbing coating (RAC) and transparent shielding film (TSF) operating within the frequency range of 7 to 12 GHz are designed and fabricated for the purpose of a radar cross section (RCS) reduction of complex naval targets such as submarines and ships. The proposed RAC consists of three layers, a shop primer, a main absorbing material, and epoxy resin paint. In addition, a TSF was fabricated by coating an ITO/Ag/ITO multilayer on a polyethylene terephthalate (PET) substrate using roll-to-roll DC plasma deposition technique. The experimental results demonstrate that the proposed RAC guarantees an RCS reduction of 10 to 15 dB from 7 to 12 GHz.

Abstract: In this work, metal/oxide/metal capacitors were fabricated and investigated using transparent boron-doped zinc oxide (ZnO:B) films for nonvolatile memory applications. Both top and bottom electrodes are tungsten. The average value of transmittance of ZnO:B films grown on silicon substrates is found to be about 91% in the visible light region. According to the relationship between transmittance and wavelength, the optical band gap of ZnO:B films is determined to be about 3.26 eV. The temperature dependent current-voltage curves show that the current density increases with increasing temperature in low-resistance state (LRS), meanwhile, the current density decreases with increasing temperature in high-resistance state (HRS). From the resistive switching behavior of the W/ZnO:B/W memory devices, the reset voltage which triggers the memory devices from an LRS to an HRS is independent of temperature. On the other hand, the set voltage which triggers the memory devices from an HRS to an LRS is increased with temperature.

Abstract: A series of clay-based nanocomposite films were prepared by casting aqueous dispersions of exfoliated montmorillonite clay mixed with various loadings of water-soluble organic polymer. The clay films with a nacre-mimicking structure exhibited excellent flexibility and optical transparency even for high clay content (93 wt%).

Abstract: The present study aims at providing an overview regarding the level of knowledge and experience gained about nanomodified surface treatments in the context of historical buildings and monuments. Nowadays, nanotechnology offers a variety of interesting cues for research, having a potential impact on every domain of science and technology. In particular, with regard to the area of surface treatments and their use in the field of historic buildings preservation, evolutionary changes may be expected. Optimized tailor-made materials and films, with previously non-achievable properties, can now be produced due to the gained ability in creation, manipulation, modeling and characterization of nanostructured systems. However, health and environmental protection issues should be considered.

Abstract: Conventional plasmonic devices involve metals, but metal-based plasmonic resonances are mainly limited to λ_res < 1 μm, and thus metals interact effectively only with light in the UV and visible ranges. We show that highly doped ZnO can exhibit λ_res ≥ 1 μm, thus moving plasmonics into the IR range. We illustrate this capability with a set of thin (d = 25–147 nm) Al-doped ZnO (AZO) layers grown by RF sputtering on quartz glass. These samples employ a unique, 20-nm-thick, ZnON buffer layer, which minimizes the strong thickness dependence of mobility (μ) on thickness (d). A practical waveguide structure, using these measurements, is simulated with COMSOL Multiphysics software over a mid-IR wavelength range of 4–10 μm, with a detailed examination of propagation loss and plasmon confinement dimension. In many cases, L_plas < λ_light, thus showing that IR light can be manipulated in semiconductor materials at dimensions below the diffraction limit.