Hydrogen Gas Sensing Characterizations Based on Nanocrystalline SnO2 Thin Films Grown on SiO2/Si and Al2O3 Substrates

2017 ◽  
Vol 268 ◽  
pp. 244-248
Author(s):  
Abu Hassan Haslan ◽  
Imad Hussein Kadhim
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Gas Sensing ◽  
Sol Gel ◽  
Hydrogen Gas ◽  
Rutile Structure ◽  
Nanoparticle Distribution ◽  
Si Substrates ◽  
Coating Method ◽  
Different Temperatures

High-quality nanocrystalline (NC) SnO2 thin films were grown on SiO2/Si and Al2O3 substrates using sol–gel spin coating method. The structural properties, surface morphologies and gas sensing properties of the NC SnO2 were investigated. XRD measurements showed a tetragonal rutile structure and the diffraction peaks for NC SnO2 thin films grown on Al2O3 substrates outperformed those of NC SnO2 films grown on SiO2/Si substrates. The surface morphology of the annealed SnO2 thin films at 500 °C appeared as polycrystalline with uniform nanoparticle distribution. Hydrogen (H2) gas sensing performance of the NC SnO2 was examined for H2 concentrations ranging from 150 ppm to 1000 ppm at different temperatures (room temperature, 75 and 125 °C) for over 50 min. The room temperature sensitivities for H2 gas sensors based on NC SnO2 thin films grown on Al2O3 and SiO2/Si substrates was 2570% and 600%, respectively upon exposure to 1000 ppm of H2 gas. While the sensitivity values at 125 °C increased to 9200% and 1950%, respectively.

Structure of Hydrogen Gas Sensing TiO2 Thin Films Prepared by Sol-Gel Method and their Comparison with Magnetron Sputtered Films

2013 ◽  
Vol 543 ◽  
pp. 293-296 ◽  
Author(s):  
G. Plesch ◽  
A.A. Haidry ◽  
M. Gregor ◽  
P. Durina ◽  
J. Gregus ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Gas Sensing ◽  
Sol Gel ◽  
Rutile Phase ◽  
Hydrogen Gas ◽  
Gel Method ◽  
Sensing Properties ◽  
Sol Gel Method ◽  
Coating Method

TiO2thin films with a thickness of about 150 nm were deposited by spin coating method on sapphire substrate from a sol-gel system. The hydrogen sensing properties of TiO2films annealed at various temperatures were studied and correlated with their structure, optical and electrical properties. The annealing temperatures in the range of 600 800 °C lead to anatase films with a roughness in the range of 0.6 0.9 nm. Their sensitivity towards hydrogen is low. The thin films annealed at temperatures in the range 900 1000 °C consist of rutile phase and their roughness increased to 11.7 13.5 nm. They showed good hydrogen sensitivity with optimal operating temperature 200 250 °C. The structure and sensing properties of the prepared films are compared with those synthesized with magnetron sputtering. The maximum of sensitivity was measured on the thin films with diameter of the grains about 100 nm in both cases, i.e. on thin films prepared by sol-gel method as well as on thin films prepared by magnetron sputtering. The maximum sensitivity correlates with the diameter of the grains and dont depend on the allotropy of the titanium dioxide anatase or rutile.

LUMINESCENT PROPERTIES OF SOL-GEL DEPOSITED Eu:TiO2 THIN FILMS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 769-773 ◽  
Author(s):  
M. GARCIA-ROCHA ◽  
A. CONDE-GALLARDO ◽  
I. HERNANDEZ-CALDERON ◽  
R. PALOMINO-MERINO
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Glass Substrates ◽  
Corning Glass ◽  
Different Temperatures ◽  
Hecd Laser

In this work we show the results on tile growth and optical characterization of TiO 2 thin films doped with Eu atoms. Eu:TiO2 films were grown at room temperature with different Eu concentrations by sol-gel on Si Corning glass substrates. A different crystalline structure is developed for the films deposited on Corning glass than those deposited on Si as observed from x-ray diffraction experiments. Room and low temperature photoluminescence (PL) was measured by using two different lines (325 and 442 nm) of a HeCd laser. A strong PL signal associated to the 5 D 0→7 F 2 transition from Eu +3 was observed. A better emission was obtained from those films deposited on Si substrates, Finally, the evolution of the PL signal is studied when the samples are annealed at different temperatures in O 2 atmosphere.

Highly responsive hydrogen gas sensing by partially reduced graphite oxide thin films at room temperature

Carbon ◽  
2012 ◽  
Vol 50 (11) ◽  
pp. 4061-4067 ◽  
Author(s):  
Jianwei Wang ◽  
Youngreal Kwak ◽  
In-yeal Lee ◽  
Sunglyul Maeng ◽  
Gil-Ho Kim
Keyword(s):  
Thin Films ◽  
Graphite Oxide ◽  
Room Temperature ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
Oxide Thin Films ◽  
Reduced Graphite Oxide

Admittance and Photoadmittance Spectroscopy of Zinc Oxide Layers Grown on p-Si Substrates by Spin Coating Method

2013 ◽  
Vol 200 ◽  
pp. 27-32
Author(s):  
Pawel Popielarski ◽  
Waclaw Bala ◽  
Kazimierz Paprocki
Keyword(s):  
Thin Films ◽  
Temperature Dependence ◽  
Dielectric Response ◽  
Ac Conductivity ◽  
Signal Amplitude ◽  
Zno Thin Films ◽  
Si Substrates ◽  
Universal Power Law ◽  
Coating Method ◽  
Different Temperatures

In this work, the dielectric response of ZnO thin films has been studied over a temperature range of 200 K - 550 K. The dielectric response of polycrystalline ZnO thin films in the frequency domain was measured from 42 Hz - to 5 MHz with a small AC signal amplitude at different temperatures. Influence of the light on conductivity has been also investigated. A universal power law relation was brought into picture to explain the frequency dependence of AC conductivity. The temperature dependence of AC conductivity was analyzed in detail. The activation energy obtained from the temperature dependence of AC conductivity was attributed to the shallow trap-controlled space charge conduction in the bulk of the sample.

Structural, Magnetic, and Electrical Properties of BiFe1-xMnxO3 Thin Films

2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Ion Concentration ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Sol Gel Process

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.

STRUCTURAL AND OPTICAL INVESTIGATIONS ON NANOCRYSTALLINE TiO2 THIN FILMS PREPARED BY SOL–GEL SPIN COATING TECHNIQUE

2010 ◽  
Vol 09 (04) ◽  
pp. 355-358 ◽  
Author(s):  
T. S. SENTHIL ◽  
M. THAMBIDURAI ◽  
N. MUTHUKUMARASAMY ◽  
R. BALASUNDARAPRABHU
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Anatase Phase ◽  
Sol Gel ◽  
Diffraction Method ◽  
Tio2 Thin Films ◽  
Nanocrystalline Tio2 ◽  
Glass Substrates ◽  
Coating Method ◽  
Different Temperatures

TiO2 thin films have been deposited onto well cleaned glass substrates by sol–gel spin coating method. The prepared TiO2 films have been annealed at different temperatures (350°C, 450°C and 550°C). The structural properties of the films have been studied using X-ray diffraction method and High Resolution Transmission Electron Microscope (HRTEM). The as-deposited films have been found to be amorphous in nature. The crystalline quality has been observed to improve with annealing temperature. The annealed TiO2 films have been found to exhibit anatase phase. The optical properties have been studied using transmittance spectrum.

Effect of Ti Content on Microstructure and Dielectric Properties of Li and Ti Co-Doped NiO Thin Films

2007 ◽  
Vol 336-338 ◽  
pp. 2639-2642 ◽  
Author(s):  
Ya Ru Zhang ◽  
Bo Ping Zhang ◽  
Yan Dong ◽  
Jing Feng Li
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Coating Method ◽  
Diffraction Peaks ◽  
Ti Content ◽  
Ti Doping ◽  
Co Doped

Li and Ti co-doped NiO thin films with 200 nm in thickness were deposited onto Pt/Ti/SiO2/ Si(100) substrates using a sol-gel spin-coating method. The effect of Ti doping content on microstructure and dielectric properties of Li0.10TixNi0.90-xO (x=5-20mol%) thin films was investigated. XRD results showed that all the Li0.10TixNi0.90-xO thin films consisted of a mixture of NiO, Li2NiO2 and NiTiO3 oxides. The intensities of the diffraction peaks for the NiTiO3 phase increased and those for NiO decreased with increasing Ti content, suggesting that a part of NiO phase combined with Ti to form NiTiO3 phase. The dielectric constants of all the Li0.10TixNi0.90-xO thin films at 102 Hz at room temperature ranged from 200 to 400 and increased with increasing Ti content. The frequency stability of the dielectric constant for the Li0.10TixNi0.90-xO thin films was also improved greatly with increasing Ti content.

Effect of the Solvent Effect of the Solvent Used During the Preparation of SnO2 Nanoparticulated Methane Sensor

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2701-2706
Author(s):  
Guillermo Carbajal-Franco ◽  
Pedro A. Ortiz-Vázquez ◽  
Alejandro Ávila-García
Keyword(s):  
Gas Sensing ◽  
Sol Gel ◽  
Dip Coating ◽  
Electric Response ◽  
Glass Substrates ◽  
Metallic Oxides ◽  
Sol Gel Process ◽  
Coating Method ◽  
Different Temperatures ◽  
Dip Coating Method

ABSTRACTGas monitoring is a relevant activity for industrial and domestic applications due to usage of dangerous gases as methane, which has been increasingly used as domestic and industrial fuel. In this field of research, metallic oxides such as SnO2, ZnO and Fe2O3 have been widely studied, but we are far from reaching the total understanding of all the parameters that can be varied; in order to improve the gas sensing properties of the metallic oxides. In this work, we present the change of properties derived from using different solvents during the preparation of SnO2 nanoparticles via the sol-gel process. The nanoparticles suspended in two different solvents were deposited on glass substrates by the dip-coating method. The addition of Sb as a dopant was studied at two different Sb:Sn ratios of 1:99 and 1:2. SEM showed differences in the nanostructured topology of the samples and EDS analysis was performed to determine the elemental composition of the samples and the ratios of doping. XRD spectroscopy was used to determine the phase of the materials and the crystallite size. Measurements of the electric response of the coatings to methane, under controlled conditions at different temperatures, were carried out and curves of sensitivity versus temperature were obtained.

scholarly journals Influence of Doping Concentration on Dielectric, Optical, and Morphological Properties of PMMA Thin Films

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Lyly Nyl Ismail ◽  
Habibah Zulkefle ◽  
Sukreen Hana Herman ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Thin Films ◽  
Dielectric Loss ◽  
Room Temperature ◽  
Sol Gel ◽  
Wavelength Region ◽  
Band Gaps ◽  
Morphological Properties ◽  
Dielectric Characteristics ◽  
Coating Method ◽  
Pmma Powder

PMMA thin films were deposited by sol gel spin coating method on ITO substrates. Toluene was used as the solvent to dissolve the PMMA powder. The PMMA concentration was varied from 30 ~ 120 mg. The dielectric properties were measured at frequency of 0 ~ 100 kHz. The dielectric permittivity was in the range of 7.3 to 7.5 which decreased as the PMMA concentration increased. The dielectric loss is in the range of 0.01 ~ –0.01. All samples show dielectric characteristics which have dielectric loss is less than 0.05. The optical properties for thin films were measured at room temperature across 200 ~ 1000 nm wavelength region. All samples are highly transparent. The energy band gaps are in the range of 3.6 eV to 3.9 eV when the PMMA concentration increased. The morphologies of the samples show that all samples are uniform and the surface roughness increased as the concentration increased. From this study, it is known that, the dielectric, optical, and morphology properties were influenced by the amount of PMMA concentration in the solution.

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