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Low-temperature processed ZnO semiconductor films were deposited onto polyethylene naphthalate (PEN) plastic substrates by a spin coating technique using ZnO nanoparticle (NP) dispersion. The ZnO nanoparticles (NPs) were synthesized by the hydrothermal method, and solution processable dispersion was used to disperse the ZnO NPs in a mixed aqueous solution with a polyvinylpyrrolidone (PVP) dispersant agent. The effects of annealing temperature (from 150°C to 250°C) on the electrical properties of glass/ZnO film samples are reported. The optimized annealing condition (200°C) was applied for ZnO film deposited on a PEN substrate. Comparative electrical properties of the PEN/ZnO film samples before and after bending tests are also presented. Experimental results show that the electrical resistivity of the PEN/ZnO film sample was 1.91 × 104Ω cm with a Hall mobility of 45.9 cm2/Vs. After bending tests, the electrical resistivity was raised to 1.26 × 105Ω cm and the Hall mobility was reduced to 31.0 cm2/Vs.

Nowadays human are exposed to an environment filling with electromagnetic waves over a wide frequency range. The electromagnetic properties of microwave absorbing materials plays an important role in the performance of civilian electromagnetic interference (EMI) shielding at low frequency range and military stealth technology at high frequency one. The electromagnetic properties include complex permittivity and permeability and its combination determines the electromagnetic wave absorption ability of a material. Complex permittivity and permeability can be measured by three different methods, i.e., free-space method, coaxial/waveguide method, and resonant cavity perturbation method. The first one requires a large space, expensive equipment, and not suitable for academic usage. In the present study, using coaxial/waveguide and resonant cavity perturbation methods, electromagnetic characteristics of iron-based microwave absorbing materials will be obtained and its microwave absorption performance will be investigated. In addition, a comparison between the measurements by these two methods will be addressed.

Nanocrystalline iron oxide powders were prepared by an inert gas condensation technique under various oxygen partial pressures. The as-prepared nanocrystalline iron oxide powders were further modified by electroless nickel plating. The as-prepared and modified nanocrystalline powders were characterized by X-ray diffraction, transmission electron microscopy, and synchrotron X-ray absorption techniques. In addition, magnetic properties of the iron oxide nanoparticles before and after electroless nickel plating were evaluated by vibrating sample magnetometer. The experimental results show that the as-prepared nanocrystalline iron oxide powders exhibited a mixture of iron and γ-Fe2O3 phases. TEM observations revealed that oxidation started from the surface of the gas-condensed iron nanoparticles. The amount of iron oxide increased with increasing oxygen partial pressure and was confirmed by synchrotron x-ray absorption examination. A decrease in saturated magnetization and coercivity of the nanocrystalline iron oxide powders was observed after electroless nickel plating.

The TFTs array fabrication process for large-area TFT-LCD has been continuously developed for simplifying processing steps, improving performance and reducing cost in the process of mass production. In this study, the hydrogenated amorphous silicon (a-Si:H) TFTs with low resistivity electrodes , silver thin films, were prepared by using the selective deposition method that combined lift-off and electroless plated processes. This developed process can direct pattern the electrode of transistor devices without the etching process and provide ease processing steps. The as-deposited Ag films were annealed at 200 oC for 10 minutes under N2 atmosphere. The results shows that the adhesion properties can be enhanced and the resistivity has been improved from 6.0 μ,-cm, significantly decrease by 35%, of as-deposited Ag films by annealed. The thickness of Ag thin film is about 100 nm and the r. m. s roughness value is 1.54 nm. The a-Si:H TFT with Ag thin films as source and drain electrodes had a field effect mobility of 0.18 cm2/Vs, a threshold voltage of 2.65 V, and an on/off ratio of 3×104.

Supercapacitive properties of Co/ZnCo oxide composite with a core–shell nanostructure (Co3O4/ZnCo2O4) prepared directly onto a nickel foam substrate by a two-step hydrothermal method were investigated. The synthesized core–shell structure consisted of some ∼40–100 nm in thick flaky ZnCo2O4deposits coated onto the surface of Co3O4nanorods measuring ∼150 nm in diameter. The specific capacitance value of the Co3O4/ZnCo2O4core–shell nanostructure synthesized by hydrothermal at 130 °C for a ZnCo2O4deposition time of 2 h can attain 1804 F g−1at a scan rate of 5 mV s−1. Furthermore, the core–shell structured electrode still exhibited a relatively good capacitance retention of more than 93% after 3000 CV cycles due to the superior structural support of Co3O4scaffolds. The Co3O4/ZnCo2O4core–shell structure exhibits excellent electrochemical performances and, as such, is one of the more promising active materials in pseudocapacitor applications.

In the present study, bismuth oxide (Bi2O3) powders were prepared from bismuth nitrate at various temperatures by spray pyrolysis (SP). The Bi2O3 powder can convert from a monoclinic α phase to a tetragonal β phase at a pyrolysis temperature of > 600° C. The crystallinity of the SP powder increased with the increase of pyrolysis temperature. The resulting SP powders were then mixed with organics and screen-printed onto the surface of LED for the evaluation of ultraviolet (UV) inhibition. The β-type bismuth oxide powder pyrolyzed at 700°C exhibited a fine crystal structure. This caused the efficiency of UV inhibition to be 97.71% when the powder concentration was as low as 9.04 wt%.

Rutile TiO2nanowires and colloidal anatase paste (film-type) were synthesized on a silicon (Si) substrate by the thermal evaporation and sol-gel process, respectively. Field-emission scanning electron microscopy images showed nanowires with diameters of 60–90nmand ∼3–4μmin length. The morphology of the anatase paste was mesoporous, and the size of the nanoparticles was 20–40nmin diameter. High-resolution transmission electron microscopy demonstrated that the rutile nanowires and anatase nanoparticles were single crystalline. Comparison of their photocatalytic properties revealed that the rutile nanowires had high specific surface area, were well-crystallized, and possessed photocatalytic activities as high as those of the mesoporous anatase paste.