Controlled growth of indium oxide nanowires for gas sensing application

Background: The In2O3 nanowires have attracted enormous attention for gas sensor application due to their advantageous features. However, the controlled synthesis of In2O3 nanowires for gas sensors is vital and challenging because the gas sensing performance of the nanowires is strongly dependent on their characteristics. Methods: Here, we fabricated In2O3 nanowires on SiO2/Si substrate via a simple thermal vapor deposition method with the Au thin film as the catalyst. The growth temperatures were controlled to obtain desired nanowires of small size. The grown In2O3 nanowires were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The ethanol gas sensing properties were tested under the dynamic flow of dry air and analytic gas. The synthesized In2O3 nanowires have the potential for use in ethanol gas sensor application. Results: In2O3 nanostructures grown at different temperatures ranging from 600 to 900oC have different morphologies. The sample grown at 600oC had a morphology of nanowire, with a diameter of approximately 80 nm and a length of few micrometers. Nanowires grown at 600 °C were composed of oxygen (O) and indium (In) elements, with the atomic ratio of [O]/[In] = 3/5. The nanowire was a single phase cubic structure of In2O3 crystal. The In2O3 nanowire sensor showed typical n-type semiconducting sensing properties. The response decreased from 130 to 75 at 100 ppm when the working temperature decreased from 450 °C to 350 °C. Conclusion: The nanowires grown at 600 °C by the thermal vapor deposition method had the best morphology with a small diameter of about 80 nm and a length of few micrometers. The In2O3 nanowires had a good ability to sense ethanol at varying concentrations in the range of 20 ppm to 100 ppm. The In2O3 nanowires can be used as building blocks for future nanoscale gas sensors.

Study on Structural and Optical Properties of Sb2S3 and CdI2 Composite Thin Films Deposited by Thermal Vapor Deposition

Thin films of Sb2S3 and CdI2 composites were deposited by thermal vapor deposition method on a glass substrate. The structural and optical properties have been investigated as a function of the film thickness. Three samples were deposited with thickness of 160[Formula: see text]nm, 210[Formula: see text]nm and 380[Formula: see text]nm. The samples were characterized by X-ray diffraction (XRD), UV–visible (UV–Vis) absorption spectroscopy and photoluminescence (PL) spectroscopy. The XRD result confirms the orthorhombic structure of Sb2S3 peaks. The bigger crystals are formed with the increase of the thickness of the film. The band gaps of the deposited composite thin films were found to be in range 2.17–1.48[Formula: see text]eV and suggest the possibility of band gap tunability in the visible region with the changing the thickness of the film. The PL study reveals the intense emission due to band to band recombination with emission in the red region corresponding to trap states.

Properties Of Thin Metal Layers Deposited On Textile Composites By Using The Pvd Method For Textronic Applications

In this paper, the results of mechanical strength tests of thin conductive Ag and Au layers created on Cordura composite substrate using the thermal vapor deposition method are presented. The resistance of the conductive layers to the bending and tensile stresses was tested and changing the surface resistance of the test structures was accepted as a criterion. The layers created on unmodified and plasma-treated surfaces have been examined. As a result of the surface modification, the electrical and mechanical properties of the thin Ag and Au metal structures have been improved. The results of measurements of surface resistance changes during strength tests and SEM microscopic studies of stressed samples indicate the high mechanical strength of the electroconductive layers deposited on Cordura, which may be the basis for the application of such technology in textronics applications.

INFLUENCE OF DEPOSITION TEMPERATURE ON OPTICAL AND LASER-INDUCED DAMAGE PROPERTIES OF LaTiO3 FILMS

LaTiO 3 films were prepared at room temperature, 60, 140 and 220°C using a thermal vapor deposition technique with an electronic beam gun to investigate the relationship between deposition temperatures and the optical properties of the samples. In the ellipsometric analysis, the corresponding refractive indexes were 1.8993, 1.9123, 1.9197 and 1.9283 at a wavelength of 1064 nm. At the same time, extremely low absorption characteristics of all the samples presented in the visible and IR regions. With the same high-energy testing laser of 200 mJ (about 40 J/cm2) at a wavelength of 1064 nm and a pulse width of 10 ns, the laser-induced damage threshold (LIDT) of the LaTiO 3 samples prepared at different temperatures were 15.5, 16.7, 18.5 and 18.2 J/cm2, respectively. This shows that a higher LIDT may be obtained at higher deposition temperatures.

Synthesis of Boron Nanowires, Nanotubes, and Nanosheets

The synthesis of boron nanowires, nanotubes, and nanosheets using a thermal vapor deposition process is reported. This work confirms previous research and provides a new method capable of synthesizing boron nanomaterials. The materials were made by using various combinations of MgB2, Mg(BH4)2, MCM-41, NiB, and Fe wire. Unlike previously reported methods, a nanoparticle catalyst and a silicate substrate are not required for synthesis. Two types of boron nanowires, boron nanotubes, and boron nanosheets were made. Their morphology and chemical composition were determined through the use of scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. These boron-based materials have potential for electronic and hydrogen storage applications.

Characterization of Si–C Covalent Bonding Fabricated between Single Carbon Nanotube and Si Substrate

The SiC covalent bonding between Carbon nanotube and Si substrate was fabricated by thermal vapor deposition using photolithography and gas blowing technology. Scanning electron microscopy, micro-Raman imaging and spectroscopy were used to investigate the interaction of individual CNTs and Si substrate. The characterization results showed that covalent bonds were formed between certain CNTs and Si substrate. Moreover, the reasons for the fabrication of SiC covalent bonding between CNTs and Si substrate were also proposed.