Commercial Glass Substrates Research Articles

Structural and optical characterization of ZrO2:CeO2 slab waveguides obtained via sol–gel

Planar multilayer ZrO2:CeO2 slab waveguides were prepared by a sol–gel route and dip-coating technique onto commercial glass substrates. The coatings were microstructurally characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and by optical confocal microscopy. Coating thicknesses of ca. 500nm and refractive index values of 2.069±0.001 and 2.087±0.001, respectively for TE and TM light polarization modes, were calculated by Dark m-line spectroscopy. This is consistent with the birefringent character of the coating, associated to the presence of anisotropic crystalline phases within the coating’s vitreous matrix. Finally, propagation losses of 0.9±0.2 and 1.5±0.2dB/cm were determined by the scattered light measurement for TE and TM polarization modes, respectively.

Electroluminescent characteristics of ZnGa2O4:Dy3+ thin film devices fabricated on glass substrates

AbstractAn alternating current thin film electroluminescent (ACTFEL) device was fabricated on commercial glass substrate with dysprosium doped zinc gallate as the active layer. The phosphor layer and the top dielectric layer were deposited using rf magnetron sputtering technique. The devices fabricated with an asymmetric double insulating structure gave a white electroluminescent (EL) emission when driven by a voltage pulse frequency of 1.5 kHz, even without post‐deposition annealing of the active layer. Such an emission resulted from the simultaneous occurrence of multicolor transitions, characteristic of the dopant ion. The exponential dependence of luminance on applied voltage was quite evident from the luminance–voltage (L–V) curves. Devices were also fabricated with a highly crystallized interfacial layer of ZnO in between the substrate and the phosphor layer. Such devices could withstand a wider range of applied voltage, henceforth resulting in enhanced device performance. The chromatic quality of the EL emissions from both the devices were gauged using chromaticity coordinates. magnified imageThe CIE coordinates of fabricated ZnGa2O4:Dy3+ ACTFEL devices (a) without and (b) with ZnO interfacial layer.

Optical and mechanical characterization of novel cobalt-based metal oxide thin films synthesized using sol–gel dip-coating method

New cobalt-based metal oxide thin films (MxCoyOz with M=Mn, Cu, Ni) have been deposited on commercial aluminum and glass substrates using sol–gel dip-coating method. The as-deposited films were characterized by a wide range of complementary techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), spectrophotometry and nanoindentation techniques. A light absorption study for coatings on glass substrates within a wavelength range of 300–1100nm was also conducted. Topographical and morphological investigations showed the presence of nano-sized, grain-like particles in the copper–cobalt oxide coatings, which consequently had the roughest surface among the three coatings. All coatings on glass substrate exhibited higher absorption of ultraviolet (UV) light compared to visible light, while coatings on aluminum substrate generally had low reflectance (<50%) of UV light, moderate reflectance (<80%) of visible light and high reflectance (up to 100%) of infrared light. Implications of optical properties as a function of film thickness controlled by dip-heating cycles were discussed. The elastic modulus (E) and hardness (H) of thin film samples compared with stand‐alone commercial aluminum substrate were also measured.

Structural and optical studies of chemically deposited Sn2S3 thin films

Sn2S3 thin films were grown on commercial glass substrates by chemical bath deposition at room temperature. The structural and optical properties of Sn2S3 thin films were studied as a function of deposition time. The thin films were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and UV–vis spectroscopy. The XRD pattern showed that the Sn2S3 thin films had an orthorhombic polycrystalline structure. The lattice constants of the thin films were a=8.741Å, b=14.034Å and c=3.728Å. The characteristic bonds of Sn2S3 were observed at 66.3, 111.7, 224.7 and 308.9cm−1 using Raman shift experiment. The optical energy band gap of the thin films decreased from 2.12eV to 2.03eV with increasing deposition time from 20 to 24h. The optical constants of the thin films were obtained using the experimentally recorded transmission data as a function of the wavelength.

Deposition Temperature Effects On Cualse2 Compound Thin Films Prepared By Chemical Bath Deposition Technique

A low cost chemical bath deposition technique has been used for the preparation of Copper aluminum diselenide (CuAlSe2) compound thin films onto commercial microscope glass substrates at variation of deposition temperature. The effects of deposition temperature (above room temperature (27°C)) towards the optical properties of the films were investigated. The optical properties were investigated by Jenway software 6405 UV-Vis spectrophotometer. The optical band gap energy of the films above room temperature ranges from 2.00 - 2.14 eV depending on the deposition temperature. Keywords: chemical bath deposition, CuAlSe2, deposition temperature, optical properties

Optical properties of amorphous CuS thin films deposited chemically at different pH values

Amorphous copper sulfide thin films were deposited on commercial glass substrates at room temperature by chemical bath deposition. The effect of the pH value of the chemical bath on the optical properties of the amorphous thin films is investigated and discussed. The influence of the pH value of the chemical bath was examined by means of the optical transmission of the thin films in the wavelength range of 300–1100 nm taken at room temperature. Next, using these data, the absorption coefficient, the optical band gap value, the extinction coefficient, the refractive index, and the real and imaginary parts of the dielectric constant were calculated. The dispersion of the refractive index of the thin films was also investigated in terms of the single-oscillator Wemple and DiDomenico method. The value of the optical band gap determined by Tauc's extrapolation was found to be equal to one and half times the oscillator energy values of all deposited films.

Effect of Low Concentration Sn Doping on Optical Properties of CdS Films Grown by CBD Technique

Thin and transparent films of doped cadmium sulfide (CdS) were obtained on commercial glass substrates by Chemical Bath Deposition (CBD) technique. The films were doped with low concentration of Sn, and annealed in air at 300 °C for 45 min. The morphological characterization of the films with different amounts of dopant was made using SEM and EDAX analysis. Optical properties of the films were evaluated by measuring transmittance using the UV-vis spectrophotometer. A comparison of the results revealed that lower concentration of Sn doping improves transmittance of CdS films and makes them suitable for application as window layer of CdTe/CIGS solar cells.

Plasmonic substrates for multiplexed protein microarrays with femtomolar sensitivity and broad dynamic range

Protein chips are widely used for high-throughput proteomic analysis, but to date, the low sensitivity and narrow dynamic range have limited their capabilities in diagnostics and proteomics. Here we present protein microarrays on a novel nanostructured, plasmonic gold film with near-infrared fluorescence enhancement of up to 100-fold, extending the dynamic range of protein detection by three orders of magnitude towards the fM regime. We employ plasmonic protein microarrays for the early detection of a cancer biomarker, carcinoembryonic antigen, in the sera of mice bearing a xenograft tumour model. Further, we demonstrate a multiplexed autoantigen array for human autoantibodies implicated in a range of autoimmune diseases with superior signal-to-noise ratios and broader dynamic range compared with commercial nitrocellulose and glass substrates. The high sensitivity, broad dynamic range and easy adaptability of plasmonic protein chips presents new opportunities in proteomic research and diagnostics applications.

Nanoimprint Fabrication and Thermal Behavior of Atomically Ultrasmooth Glass Substrates with 0.2-nm-Height Steps

We examined the conditions for the development of atomically stepped ultrasmooth surfaces on commercial silicate glass substrates by the thermal nanoimprint technique using sapphire (α-Al2O3 single crystal) molds with 0.2-nm-height atomic steps. Under the pressing conditions of 3 MPa, 300 s, and 610 °C for imprinting, a 0.2-nm-high stepped and atomically ultrasmooth terraced surface could be formed on soda-lime silicate glass substrates having the glass transition temperature of 521 °C. We found that the 0.2-nm-height step structure of the imprinted glass surface disappeared after annealing at 490 °C, and the smoothness of the terrace increased.

Bidimensional codes recorded on an oxide glass surface using a continuous wave CO2 laser

Surface heat treatment in glasses and ceramics, using CO2 lasers, has attracted the attention of several researchers around the world due to its impact in technological applications, such as lab-on-a-chip devices, diffraction gratings and microlenses. Microlens fabrication on a glass surface has been studied mainly due to its importance in optical devices (fiber coupling, CCD signal enhancement, etc). The goal of this work is to present a systematic study of the conditions for microlens fabrications, along with the viability of using microlens arrays, recorded on the glass surface, as bidimensional codes for product identification. This would allow the production of codes without any residues (like the fine powder generated by laser ablation) and resistance to an aggressive environment, such as sterilization processes. The microlens arrays were fabricated using a continuous wave CO2 laser, focused on the surface of flat commercial soda-lime silicate glass substrates. The fabrication conditions were studied based on laser power, heating time and microlens profiles. A He–Ne laser was used as a light source in a qualitative experiment to test the viability of using the microlenses as bidimensional codes.

Effect of ITO/Ag/ITO Multilayer Electrode Deposited onto Glass and PET Substrate on the Performance of Organic Light-Emitting Diodes

The transparent conductive oxide (TCO) electrode is an important part of organic light-emitting diodes (OLEDs), especially for the OLEDs based on flexible substrate. We fabricated indium tin oxide (ITO)/Ag/ITO multilayer films deposited on polyethylene terephthalate (PET) film by using sputtering technique at room temperature in order to achieve high transmittance and low sheet resistance for application to flexible OLED devices. The OLEDs made with ITO/Ag/ITO multilayer deposited on flexible film exhibited lower operating voltage and higher current efficiency than the OLEDs made with commercial single layer ITO glass substrate.

Effect of temperature on glass-ceramic films prepared by impregnation of commercial float glass surfaces with oxide powders under pressure

SnO 2 samples were prepared as ultrafine powder by a chemical synthesis method and deposited on the surface of commercial float glass substrates. The glass surface was impregnated with these powders under high gas pressure (1.6–1.8 MPa) and heating to below the glass transition temperature in a designed pressurized chamber, forming SnO 2 films on glass surface. Phases were analyzed by X-ray diffraction and the results confirmed the SnO 2 powders as a single-phase tetragonal structure. Analysis of the chemical composition of glass substrates before and after powder impregnation revealed an ion exchange process caused by the substitution of sodium ions by tin ions on the glass surface. Differences in the surface morphology of SnO 2 films on glass surface were related to the morphology of synthesized powders for deposition and impregnation. The mechanism of SnO 2 films on glass surface was based on mass transfer between the glass substrates and SnO 2 powders as a function of the treatment temperature.

Optical properties of CVD grown amorphous Ge–Sb–S thin films

Germanium antimony sulphide (Ge–Sb–S) amorphous thin films have been fabricated on commercial glass substrates by chemical vapour deposition (CVD). The compositions and thicknesses of these thin films have been characterized by micro-Raman, scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX) techniques. Optical transmission spectra measured by UV–VIS-NIR spectrometer have been used to determine the optical properties of these CVD-grown Ge–Sb–S amorphous thin films with Swanepoel’s methods. Optical band gaps of these films were calculated from Tauc’s extrapolation procedure. The dispersions of the refractive indices of these films have also been determined using the Wemple–DiDomenico method.

Microstructure of ceramic particles infiltrated into float glass surfaces by high gas pressure impregnation

Glass–ceramics were produced by impregnation of powders onto a surface under pressure. Samples of four classes of oxide powders (SnO 2, Co 3O 4, TiO 2and Al 2O 3) were infiltrated into a commercial float glass substrate. These powders were impregnated on the glass surface under high gas pressure (16–18 atm) and below the T g temperature in a specially designed pressurized chamber to form M x O y –SiO 2 films. The phases were analyzed by X-ray diffraction (XRD), and the results reveal the structure and crystallinity of the selected oxide powders as prepared and after inclusion in the glass substrate. The formation of films by the proposed method is viable due to the mean particle size of the powders deposited on the glass surface. Differences in the surface morphology of glass–ceramics films were attributed to the morphology of the powders used for impregnation. The formation mechanism of M x O y –SiO 2 films was based on compositional differences in the glass substrate before and after the powder impregnation process and on their surface morphology.

Fabrication of superhydrophobic ZnO/Zn surface with nanowires and nanobelts structures using novel plasma assisted thermal vapor deposition

Superhydrophobic ZnO surfaces with a contact angle of about 157° and a tilt angle lower than 9° were fabricated on commercial glass substrates via novel plasma assisted thermal vapor deposition method. Interconnected ZnO nanobelts and nanowires were constructed on the glass surfaces by Ar plasma activated Zn vapor deposition and then followed by a low-pressure-air (5 Pa) thermal oxidation at 350 °C. The resulting glass slides uniformly covered with nano-structured ZnO exhibited excellent superhydrophobic properties without any additional chemical modification. Moreover, the transparency and conductivity of the ZnO glass slides could be regulated easily by varying the oxidation parameters. The results of this study might pave a new pathway to the fabrication of superhydrophobic transparent conducting surface used in engineering fields.

Influence of ZnO Content on Film Morphology and Device Performance of MEH-PPV/ZnO Hybrid Solar Cells

Hybrid solar cells based on conjugated polymer poly(2-methoxy,5-(2’-ethylhexyloxy)-p-phenylene vinylene (MEH-PPV) and inorganic n-type zinc oxide (ZnO) nanoparticles were investigated. Polymer solar cells consisting of conducting polymer alone have low minority carrier mobility, for example, MEH-PPV has a high hole mobility but a low electron mobility. The intrinsic carrier mobility imbalance in the MEH-PPV severely limits the performance of pure polymer based solar cells. To overcome this imbalance, another material, i.e. n-type ZnO particles, is incorporated to act as an electron acceptor and a pathway for electron transport. In this experiment, as an active layer, ZnO nanoparticles synthesized in-house were blended with MEH-PPV purchased from Sigma-Aldrich. The front transparent conduction oxide (TCO) electrode used was commercial glass substrate coated with indium tin oxide (ITO) thin film. Blends of MEH-PPV with 0-30 wt% of ZnO in 1,2-dichlorobenzene were prepared and fabricated as active layers of the solar cells. The PEDOT:PSS and active layer were spin-coated onto ITO coated glass substrate. Aluminum was used for the top electrodes. The effects of ZnO solid content and film morphology on the performance of MEH-PPV:ZnO nanoparticle composite solar cells were investigated. Transmission electron microscopy (TEM) revealed that the ZnO nanoparticles consisted of a mixture of spherical and rod-like shapes. An increase in ZnO solid content resulted in an increase in size of the ZnO network. This was found to increase electron transport and, hence, improve solar cell performance.

Intrinsic magnetism in Zn1−xCoxO (0.03≤x≤0.10) thin films prepared by ultrasonic spray pyrolysis

The Zn1−xCoxO thin films were prepared on a commercial glass substrate at400 °C by ultrasonic spray pyrolysis. The effect of doping concentration on thestructural, optical and magnetic properties of these films has been studied.The structural and optical properties of these films reflect the fact that theCo2+ ions havesubstituted the Zn2+ ions without changing the wurtzite structure of ZnO. We have not observed any secondaryphases even after doping the 10 at.% concentration of Co. All the films were highly orientedwith preferred (002) direction. By increasing the Co content, a systematic change in both thec-axis lattice constant and the fundamental band gap energy was observed. Threeabsorption bands were found in the transmission spectra of the Co doped ZnO films at657 nm (1.89 eV), 610 nm (2.03 eV) and 567 nm (2.20 eV). The absorption bands wereattributed to d–d intraionic transitions of tetrahedrally coordinated high-spinCo2+ ions. Magnetic studies reveal the absence of room temperatureferromagnetic behaviour in these films. The values of coercivity(HC)∼145 and 123 Oe andremanent magnetization (Mr)∼4.32 × 10−5 and 7.28 emu cm−2 wereobserved at 5 K for Zn0.95Co0.05O and Zn0.93Co0.07O thin films.

OLED용 ITO박막의 공정조건과 품질특성 추론에 근거한 품질관리

Recently, research on a flat panel display(FPD) has focused on organic light-emitting display(OLED) which has wide angle of view, high contrast ratio and low power consumption. ITO(Indium-Tin-Oxide) films are the most widely used material as a transparent electrode of OLED and also in many other display devices like LCD or PDP. The performance and efficiency of OLED is related to the surface condition of ITO coated glass substrate. The typical surface defect of glass substrate is measured for electric characteristics and physical condition for transmittance and roughness. Since ITO coated glass substrate can be destroyed for inspection about surface roughness, sheet resistance, film thickness and transmittance, precise fabrication condition should be made based on the estimated relationship. In this paper, ITO films were prepared on the commercial glass substrate by the Ion-Plating method changing the partial pressure of gas(Ar, 02) and the chamber temperature between <TEX>$200^{\circ}C$</TEX> and <TEX>$300^{\circ}C$</TEX>. The characteristics of films were examined by the 4-point probe, supersonic thickness measurement, transmittance measurement and AFM. We estimated the relationship between processing parameters(Ar gas, O2 gas, Temperature) and properties of ITO films (Sheet Resistance, Film Thickness, Transmittance, Surface Roughness).

Growth mechanism and characterisation of chemically grown Sb doped Bi 2Se 3 thin films

The synthesis of combinatorial Bi 2− x Sb x Se 3 thin films by arrested precipitation technique (APT) using triethanolamine-bismuth, triethanolamine-antimony and sodium selenosulphite as sources of Bi 3+, Sb 3+ and Se 2−, respectively is investigated on commercial glass substrates. The growth mechanism of film formation, composition and surface morphology of the as deposited films were studied as a function of preparative parameters and bath composition. The films were monophasic, polycrystalline and covered the surface of the substrate completely. Energy dispersive X-ray analysis gave coherent elemental composition indicating single phase BiSbSe 3 was made. The good results obtained for Bi 2− x Sb x Se 3 thin films revealed that arrested precipitation technique is best suited for the deposition of large area thin films on conducting/nonconducting substrates to produce materials for device applications.

Photoluminescence of ZnO layer on commercial glass substrate prepared by sol–gel process

Amorphous ZnO thin film on soda–lime–silica glass substrate was prepared by the sol–gel process at low-temperature processing, i.e., 100 °C. No distinct grain structure was observable in the surface of the film. The photoluminescence spectrum of the ZnO thin film with an intense near band edge emission was observed while the defect-related broad green emission was nearly quenched.