Preparation of Transparent Thick Films by Electrophoretic Sol-Gel Deposition Using Phenyltriethoxysilane-Derived Particles

Thick films were prepared on glass substrates coated with indium tin oxide (ITO) via electrophoretic deposition using sols that contained phenylsilsesquioxane (PhSiO_3/2) particles derived from phenyltriethoxysilane. The transparency of the thick PhSiO_3/2 films was significantly improved via heat treatment at temperatures >200°C. Scanning electron microscopy observation showed that the thick films changed in morphology, from aggregates of particles with several open spaces among the particles to a monolith with no open spaces after the heat treatment. Transparent films ~3 µm thick were obtained when the films were heat-treated at a temperature of 400°C for 2 h.     

Investigations of Electrical Properties in Silica/Indium Tin Oxide Two-Layer Film for Effective Electromagnetic Shielding

The effect of zinc ions added to silica film on the electrical and structural properties of a silica/indium tin oxide two-layer film which had been prepared by solution coating for electromagnetic shielding of displays was studied. The volume resistivity of the undoped silica/indium tin oxide film was more than 3 times as high as that of the zinc-doped silica/indium tin oxide film. The addition of divalent cations, zinc ions, to the overcoated layer led volume resistivity of the two-layer film to decrease significantly and also caused a long-term increase in stability. The decrease in volume resistivity was due to the addition of zinc ions that changed the interface ionization and helped to enhance the electrical conductivity in the two-layer film.     

Continuous Synthesis of Tin and Indium Oxide Nanoparticles in Sub- and Supercritical Water

Nanocrystalline tin and indium oxides (In₂O₃/SnO₂) were synthesized in sub- and supercritical water at 350°/380°C and 30 MPa in <73 s in a tubular flow reactor from an aqueous solution of {SnCl₄+InCl₃} (0.2 M ). The conversion rate for tin was 100%. Nanoparticles were analyzed by transmission electron microscopy (TEM), emitted X-rays, Raman, differential scanning calorimetry, and X-ray diffraction techniques. The bulk particles were composed of In, Sn, and O atoms, and made up of cubic In₂O₃ (10 nm) and tetragonal SnO₂ (5.5 nm) crystals. After calcination at 500°C for 2 h, little change occurred in the particle size and crystal phase. Traces of tin-doped indium oxide particles were also formed as confirmed by the TEM electron diffraction pattern. Using this one-step, high-temperature hydrothermal process, oxide nanoparticles can be continuously and conveniently produced in a well-controlled process.     

Micropatterning of Transparent Poly(Benzylsilsesquioxane) Thick Films Prepared by the Electrophoretic Sol–Gel Deposition Process Using a Hydrophobic–Hydrophilic-Patterned Surface

Poly(benzylsilsesquioxane) (BnSiO_3/2) particles show glass transition behavior, and the particles become a supercooled liquid when they are heated at temperatures above the glass transition temperature. Contact angles of BnSiO_3/2 molten liquid on the hydrophobic surface with fluoroalkylsilane and hydrophilic surface with silica were found to be around 77° and 12°, respectively. Using the difference in wettability for BnSiO_3/2 molten liquid between the hydrophobic and hydrophilic surfaces, micropatterns of transparent BnSiO_3/2-thick films were formed by the electrophoretic deposition of BnSiO_3/2 particles on indium tin oxide substrates with hydrophobic–hydrophilic patterns and subsequent heating above the glass transition temperature.     

Oriented Lead Titanate Film Growth at Lower Temperatures by the Sol-Gel Method on Particle-Seeded Substrates

An approach to fabricate lead titanate (PbTiO₃) films with preferred orientation on arbitrary substrates by a sol-gel method was developed. To ensure a preferred crystallographic orientation on the substrates with different crystal structure, well-defined platelet PbTiO₃ particles were used as seeds. Because the basal plane of the platelet-shaped particles was the (001) plane, the particles aligned with the c-axis perpendicular to the substrates. During crystallization of the sol-gel PbTiO₃ films on the particle-seeded substrate, preferential nucleation occurred on seeded particles with the same crystallographic orientation as the particles at a much lower temperature. In the current study, (100) and (001) textured PbTiO₃ films have been produced on various substrate materials such as silicon, silicate glass, indium tin oxide (ITO) glass, and titanium metal at temperatures as low as 275°C. The microstructure of the films was examined by scanning electron microscopy and atomic force microscopy. Limited ferroelectric properties also were determined, to underscore the preferred orientation that was produced in these materials.     

Fabrication and characterization of Ag-Decorated indium–tin-oxide nanoparticle based ethanol sensors using an enhanced electrophoretic method

In this paper different Indium Tin Oxide (ITO)-based ethanol vapor sensors (fabricated as thin films and nanoparticles) are presented, and their structural and sensing properties are investigated. An Electrophoretic Deposition (EPD)-Enhanced method is proposed for the fabrication of pure, and Ag-decorated indium tin oxide sensors. The proposed sensors are then compared to conventional indium tin oxide sensors fabricated by sputtering (thin film), and drop-casting method in terms of response, and working temperature. It is shown that the electrophoretic deposition method has decreased the final particle size of the indium tin oxide nanoparticles by limiting the agglomeration of nanoparticles, and increased the sparsity of the particles forming the sensing material. Results suggest that compared to the conventional sensors, the sensors fabricated by the proposed electrophoretic deposition method (i.e., the pure-indium tin oxide (EPD-TF), and the Ag-decorated indium tin oxide (Ag-EPD) sensors), has considerably better performance for the detection of the ethanol vapors, showing reduced working temperature (110 and 130 °C, respectively), higher response, and better selectivity over CO, methane, methanol, and acetone. Moreover, the response and recovery time of the proposed sensors were found to be lower than most of the previously reported indium tin oxide-based ethanol sensors, approving the positive effect of the electrophoretic method as a simple, controllable method for sensor fabrication.     

Microstructure Effects in Multidipped Tin Oxide Films

Porous ultrafine tin oxide films (particle size 70–90 Å) have been prepared from tin alkoxide by dip coating. The influence of the number of coating applications on the thickness, microstructure, and electrical properties of multidipped tin oxide films was investigated. With an increase in the number of coating applications, the porosity of the multidipped films decreased from 60% to 12%, but the particle size of the films increased. The resistivity of the films decreased from 5.5 × 10^–2 to 5.7 × 10^–3Ω·cm with increasing the number of coating applications from 1 to 10. This tendency of the resistivity to decrease is due to the microstructural change of the films with the number of coating applications. The microstructure, the surface structure, and the composition of the multidipped films were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Auger electron spectroscopy (AES).     

Characterization and Electrophoretic Deposition of Poly(Phenylsilsesquioxane)–Titania Hybrid Particles Prepared by the Sol–Gel Method

Poly(phenylsilsesquioxane)–titania (PhSiO_3/2–TiO₂) hybrid particles were prepared from phenyltriethoxysilane and titanium tetra- n -butoxide by the sol–gel method. Fourier transform infrared spectra showed that PhSiO_3/2 and the TiO₂ components were hybridized through Si–O–Ti bonds. The refractive index of the particles was monotonically increased from 1.57 to 1.62 with an increase in the TiO₂ content. The PhSiO_3/2–TiO₂ particles were electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates to form opaque, thick films about 3 μm in thickness. When the mole ratio x in (1− x )PhSiO_3/2· x TiO₂ was equal to or less than 0.05, the deposited PhSiO_3/2–TiO₂ films became transparent with a heat treatment at 400°C because of the thermal sintering of the particles.     

Effect of Phase Transformation on the Densification of Coprecipitated Nanocrystalline Indium Tin Oxide Powders

Two kinds of nanocrystalline indium tin oxide (ITO) powders with different crystal structures—rhombohedral and cubic—were prepared using a coprecipitation process through the control of aging time of precipitates after coprecipitation. The densification characteristics of the two ITO powders were examined. During sintering the rhombohedral ITO, which is a high-pressure phase, was transformed to cubic around 900°C. The phase transformation induced coarsening of grains and many voids in the microstructure retarded densification. On the other hand the cubic ITO, which did not experience phase transformation during sintering, was well densified as the sintering temperature increased. Poor densification of the rhombohedral ITO powder is explained from the viewpoint of coarsening of grains during the phase transformation. This result shows the significance of phase transformation during sintering.     

Hydrolysis Deposition of Thin Films of Antimony-Doped Tin Oxide

Thin films of antimony-doped tin oxide have been obtained by a new technique, the so-called hydrolysis deposition method, in which hydrolyzed solids are precipitated from metal fluoride solutions. Mixed solutions of SnF₃ and SbF₃ produce antimony- and fluorine-doped tin oxide films. The amount of antimony can be controlled in a wide range by adjusting the initial fluoride concentrations of the solution. The film containing 2.9 mol% antimony heated at 500°C has an electrical resistivity of 1.0 × 10⁻³Ω·cm, which is lower than previously obtained by wet-chemical techniques.     

Transparent and conductive indium tin oxide/polyimide films prepared by high‐temperature radio‐frequency magnetron sputtering

A highly transparent and thermally stable polyimide (PI) substrate was prepared and used for the fabrication of indium tin oxide (ITO)/PI films via radio‐frequency magnetron sputtering at an elevated substrate temperature. The effect of the deposition conditions, that is, the oxygen flow rate, substrate temperature, sputtering power, and working pressure, on the optical and electrical properties of the ITO/PI films were investigated from the microstructural aspects. The results indicate that the optical and electrical properties of ITO were sensitive to the oxygen. Moreover, it was beneficial to the improvement of the ITO conductivity through the adoption of a high substrate temperature and sputtering power and a low working pressure in the deposition process. A two‐step deposition method was developed in which a thick bulk ITO layer was overlapped by deposition on a thin seed ITO layer with a dense surface to prepare the highly transparent and conductive ITO/PI films. The ITO/PI film after annealing at 240°C gave a transmittance of 83% and a sheet resistance of 19.7 Ω/square. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42753.     

Synthesis of antistatic hybrid nanocomposite coatings using surface modified indium tin oxide (ITO) nanoparticles

Several antistatic nanocomposite hybrid coatings based on epoxy-silane developed by sol–gel method are studied. The hybrid sols are prepared by hydrolysis and condensation of GPTMS and TMOS precursors in the presence of an acid, as catalyst, and EDA as curing agent. Considering their good electrical conductivity, indium tin oxide (ITO) nanoparticles are used as antistatic agents. To improve the distribution/dispersion of ITO nanoparticles in the polymer matrix, the surface of nanoparticles is modified with silane groups (m-ITO). The antistatic properties of the coatings, containing various amounts of m-ITO nanoparticles, are investigated through surface electrical resistivity measurements. FTIR is used to screen the reaction of epoxy groups and the effect of EDA on crosslinking in the hybrid coatings. Morphology, nanoparticle distribution and surface roughness of the coatings are studied through SEM and AFM microscopy techniques. Also, homogeneous distribution of ITO nanoparticles within the polymer matrix is confirmed by EDXA elemental mapping. The cubic shape and nanometric size of the nanoparticles in the hybrid coatings are monitored by transmission electron microscopy (TEM).     

Low-Temperature Fabrication and Enhanced Ferro- and Piezoelectric Properties of Bi3.7Nd0.3Ti3O12 Films on Indium TinOxide/Glass Substrates

Bi_3.7Nd_0.3Ti₃O₁₂ (BNT0.3) films were fabricated on indium tin oxide/glass substrates using a metal organic decomposition method at temperatures ranging from 500° to 650°C. A predominantly (100)-oriented BNT0.3 film can be obtained even at 550°C. The growth mode of the predominantly (100)-oriented BNT0.3 films fabricated by the sequential layer annealing method was discussed based on the structure evolution with the annealing temperature and the film thickness. The largest values of the remanent polarization and piezoresponse are observed in the BNT0.3 film annealed at 650°C, which can be ascribed to the grain growth and the release of the in-plane residue tension stress.     

Conductive indium-tin oxide nanowire and nanotube arrays made by electrochemically assisted deposition in template membranes: switching between wire and tube growth modes by surface chemical modification of the template

Tin-doped indium hydroxide (InSnOH) nanowires (NWs) and nanotubes (NTs) were grown from acidic aqueous solutions of inorganic precursors in a simple one-step electrochemically assisted deposition (EAD) process inside Au-plugged anodic aluminium oxide and polycarbonate membranes. When the membranes were used without any pre-treatment, InSnOH crystals nucleated on the both the Au-cathode and pore wall surfaces. By adjusting the surface chemistry of Au or the pore walls, it was possible to switch between NW and NT growth modes. InSnOH was converted into indium tin oxide (ITO) by annealing the InSnOH-filled membranes at 300 °C. The resulting wires and tubes were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray and electron diffraction, Auger electron spectroscopy and electrical conductivity measurements. InSnOH and ITO NWs and NTs consisted of ～25-50 nm in size crystalline grains with the cubic crystal structures of In(OH)(3) and In(2)O(3), respectively, and showed essentially the same morphological features as planar ITO films made by the same method. Separate tin oxide/hydroxide phases were not observed by any of the characterization methods. After heating in air at 600 °C, the ITO NWs had resistivity on the order of 10°Ω cm. EAD is an inexpensive and scalable solution-based technique, and allows one to grow dense arrays of vertically aligned, crystalline and conductive ITO NWs and NTs.     

氧化铁/石墨烯原位复合物对铬酸钾吸附性能研究

采用共沉淀法制备Fe_3O_4磁性纳米颗粒以及通过原位生长法制备Fe_3O_4与氧化石墨烯的复合物,并加入十六烷基三甲基溴化铵形成共价键交联反应化合物。采用X射线衍射仪和透射电子显微镜表征样品的形貌与尺寸,并以铬酸钾为吸附对象,研究吸附温度、吸附时间和溶液p H值对Fe_3O_4吸附性能的影响。结果表明,椭圆形颗粒的Fe_3O_4尺寸约(10~15)nm,与氧化石墨烯复合后,分散性明显提高;在室温和p H=3.5条件下,以Fe_3O_4与氧化石墨烯的质量比2∶1复合物作为吸附剂对铬酸钾的吸附效果达到最佳,每克的吸附容量可达251 mg;复合物经过磁分离、反复吸附循环实验6次后,对铬酸钾的吸附率仅下降10个百分点。     

One-step elaboration of flexible transparent conductive electrodes from silver nanowires/polymer nanocomposites

A new simplified low temperature deposition method to manufacture flexible transparent conductive electrodes (FTCE) based on conductive polymer composite filled with silver nanowires (AgNWs) was investigated. Polyurethane/AgNWs composite was deposed on a poly(ethylene terephthalate) substrate as a conductive paint in a thin layer lower than 2 μm. The high aspect ratio nanowires influence on the electrical behavior is followed with surface resistivity and optical transparency experiments. The best compromise was obtained with a conductive layer filled with 2.84 vol.% of AgNWs; it exhibits a surface resistivity of 143 Ω/sq with 73% in transmittance. These transparent conductive composites processing in one step with good touching manipulation resistance demonstrate the real interest for this kind of FTCEs technology without indium tin oxide.     

Morphological and structural studies of nanoporous nickel oxide films fabricated by anodic electrochemical deposition techniques

Porous nickel oxide films are directly deposited onto conducting indium tin oxide coated glass substrates by cyclic voltammetric (CV), galvanostatic, and potentiostatic strategies in a plating bath of sodium acetate, nickel sulfate, and sodium sulfate. By tuning the deposition parameters, it is possible to prepare nickel oxide films with various morphologies and structures. Film formation relies on the oxidation of dissolved Ni²⁺ to Ni³⁺, which further reacts with the available hydroxide ions from a slightly alkaline electrolyte to form insoluble nickel oxide/hydroxide deposits on the substrate. A compact film with particularly small pores is obtained by CV deposition in a potential range of 0.7-1.1 V. A galvanostatically deposited film is structurally denser near the surface of the substrate, and becomes less dense further away from the surface. Interestingly, a potentiostatically deposited film has pores distributed uniformly throughout the entire film. Therefore, for obtaining a uniform film with suitable pore size for electrolyte penetration, potentiostatic deposition technique is suggested. In addition, except for CV deposition, the deposited films resemble closely to cubic NiO when the annealing temperature exceeds 200 °C.     

Influence of annealing atmosphere on the structure, resistivity and transmittance of InZnO thin films

Dependence of the electrical and optical properties of In₂O₃–10 wt% ZnO (IZO) thin films deposited on glass substrates by RF magnetron sputtering on the annealing atmosphere was investigated. The electrical resistivities of indium zinc oxide (IZO) thin films deposited on glass substrate can be effectively decreased by annealing in an N₂ + 10% H₂ atmosphere. Higher temperature (200 °C) annealing is more effective in decreasing the electrical resistivity than lower temperature (100 °C) annealing. The lowest resistivity of 6.2 × 10⁻⁴ Ω cm was obtained by annealing at 200 °C in an N₂ + 10% H₂ atmosphere. In contrast, the resistivity was increased by annealing in an oxygen atmosphere. The transmittance of IZO films is improved by annealing regardless of the annealing temperature.     

纳米氧化铟锡透明隔热涂料的制备及性能表征

采用在水中分散好的氧化铟锡(ITO)水浆，以及有机硅树脂成膜剂，通过加入共溶剂并调整体系pH值，制得了性能好的透明隔热涂料。试验结果表明，该涂料具有良好的光谱选择性，在可见光区具有高的透过性，并能有效阻隔红外光区的热辐射。     

Effects of Annealing Temperature on Microstructure and Electrical and Optical Properties of Radio-Frequency-Sputtered Tin-Doped Indium Oxide Films

Indium tin oxide (ITO) films (0.3 μm thick), with a doping level of 28 mol% SnO₂, were prepared by a radio frequency magnetron sputtering mehthod. The effects of postannealing on the microstructure and the electrical properties of the ITO films were investigated. The as-sputtered film showed an amorphous structure, whereas the films annealed at 350° and 510°C exhibited crystalline structures with grain sizes of 0.12 and 0.14 μm, respectively. Examination by TEM showed that the postannealing treatment induced SnO₂ precipitates along the grain boundaries. The resistivity increased with increasing postannealing temperatures. The mobility of carriers appears to be responsible for the resistivity increase in these specimens. The mobility change is discussed in connection with the SnO₂ precipitates.