scholarly journals Synthesis Of Zincoxide Nanorods And Its Application To Humidity Sensor

2015 ◽  
Vol 20 (1) ◽  
pp. 36-39 ◽  
Author(s):  
Indra Bahadur Karki ◽  
Jeevan Jyoti Nakarmi ◽  
Suman Chatterjee
Keyword(s):  
Thin Films ◽  
Glass Substrate ◽  
Humidity Sensor ◽  
Sol Gel ◽  
Zno Nanorods ◽  
X Ray Diffraction ◽  
Humidity Sensors ◽  
X Ray ◽  
Sem Image ◽  
Humid Environment

The present study is concerned the sensing behavior of ZnO nanorods thin films application to humidity sensors. ZnO nanorods were fabricated on a glass substrate by sol-gel spin coating technique. The crystal structure of the resulting thin films was investigated by X-ray diffraction (XRD). Minimum crystalline grain size of this film was found about 5nm. Surface morphology of the film was investigated by Scanning Electron Microscope (SEM). SEM image shows rods like films which are evenly distributed on the surface of the sample. The film on a glass substrate explored for humidity sensing of controlled humid environment by measuring electrical resistance. The resistance falls from M Ohms to K ohms as percentage relative humidity increases from 20 to 90 %.Journal of Institute of Science and Technology, 2015, 20(1): 36-39

Optical Properties of Cadmium Sulphide (CdS) Thin Films Spin-Coated on Glass Substrates

2021 ◽  
Vol 14 (1) ◽  
pp. 49-58
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Extinction Coefficient ◽  
Spin Coating ◽  
Glass Substrate ◽  
Annealing Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sem Image ◽  
Cds Thin Films

Abstract: CdS thin films were synthesized on a glass substrate using spin coating method. The effects of annealing temperature on the optical properties of the prepared CdS films were investigated for different annealing temperatures of 200, 300 and 400 °C. Cadmium acetate, thiourea and ammonia were used as the source materials for the preparation of the thin films. The elemental composition, morphological, optical and structural properties of the films obtained by spin coating were investigated using Energy Dispersive X- ray Spectroscopy (EDAX), Scanning Electron Microscope (SEM), UV Spectrophotometry and X-ray diffraction (XRD) respectively. The SEM image of the unannealed film shows a spherical morphology and an irregular pattern without any void. It also shows that the film covers the substrate well. Annealing leads to an increase in transmittance with the highest transmission of 87% observed for the film annealed at 400oC. With increase in annealing temperature, optical parameters like extinction coefficient and dielectric constants show a reduction, while refractive index and skin depth exhibit an improvement. The absorption coefficient increases with increasing photon energy in the range 3.6 to 4.0 eV. The band gap values of the CdS thin film samples were found to be in the range between 3.14 eV and 3.63 eV. The bandgap is somewhat greater than the value of bulk CdS due to quantum size effect. EDX image confirmed the presence of Cadmium and Sulphur in the prepared CdS films. Annealing did not significantly change the extinction coefficient. The X-ray diffraction confirms the cubic structure of CdS deposited on glass substrate, where reflections from (111), (200), (220) and (311) planes are clearly shown with a preferential orientation along (111) plane. Debye-Scherer equation was used to determine the crystallite size of the most intense plane (111) and the value was found to be 8.4 nm. Keywords: SEM image, Spin coating, Surface morphology, Optical properties, Annealing.

ITO Thin Films on Silicon Buffer by Sol Gel Method

2006 ◽  
Vol 514-516 ◽  
pp. 1155-1160 ◽  
Author(s):  
Talaat Moussa Hammad
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Optical Transmission ◽  
Sol Gel ◽  
Precursor Solution ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ito Thin Films ◽  
Uv Visible

Sol gel indium tin oxide thin films (In: Sn = 90:10) were prepared by the sol-gel dipcoating process on silicon buffer substrate. The precursor solution was prepared by mixing SnCl2.2H2O and InCl3 dissolved in ethanol and acetic acid. The crystalline structure and grain orientation of ITO films were determined by X-ray diffraction. The surface morphology of the films was characterized by scanning electron microscope (SEM). Optical transmission and reflectance spectra of the films were analyzed by using a UV-visible spectrophotometer. The transport properties of majority charge carriers for these films were studied by Hall measurement. ITO thin film with electrical resistivity of 7.6 ×10-3 3.cm, Hall mobility of approximately 2 cm2(Vs)-1 and free carrier concentration of approximately 4.2 ×1020 cm-3 are obtained for films 100 nm thick films. The I-V curve measurement showed typical I-V characteristic behavior of sol gel ITO thin films.

Sol-Gel derived Bi4-xNdxTi3O12 Thin Films and Their Characterization

2002 ◽  
Vol 737 ◽  
Author(s):  
R.E. Melgarejo ◽  
M.S. Tomar ◽  
A. Hidalgo ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Sol Gel Process ◽  
Ferroelectric Memory ◽  
Initial Results

ABSTRACTNd substituted bismuth titanate Bi4-xNdxTi3O12 were synthesized by sol-gel process and thin films were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. Thin films, characterized by X-ray diffraction and Raman spectroscopy, shows complete solid solution up to the composition x < 1. Initial results indicate that the ferroelectric polarization increases with increasing Nd content in the film with 2Pr = 50μC/cm2 for x = 0.46, which may have application in non-volatile ferroelectric memory devices.

Synthesis and Characterizations of Strontium Substituted Hydroxyapatite Thin Films

2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Composition ◽  
Spin Coating ◽  
Phase Structure ◽  
Sol Gel ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.

CuO Nanostructure by Oxidization of Copper Thin Films

2008 ◽  
Vol 55-57 ◽  
pp. 645-648
Author(s):  
Phathaitep Raksa ◽  
A. Gardchareon ◽  
N. Mangkorntong ◽  
Supab Choopun
Keyword(s):  
Thin Films ◽  
Oxidation Reaction ◽  
Dye Sensitized Solar Cells ◽  
X Ray Diffraction ◽  
Copper Thin Film ◽  
X Ray ◽  
Sem Image ◽  
Dye Sensitized ◽  
Cuo Nanostructure ◽  
Sensitized Solar Cells

CuO nanostructures were synthesized by oxidizing copper thin films. The copper thin film was grown on alumina substrates by evaporation copper powder at pressure of 0.04 mtorr. The copper thin films were then oxidized 800, and 900oC for 12, 24 and 48 hr, respectively. The obtained CuO nanostructures were investigated by Energy Dispersive Spectroscopy (EDS), Field Emission Scanning Electron Microscope (FE-SEM) image, and X-Ray Diffraction (XRD). The diameter of CuO nanostructure is around 100-600 nanometers and it is depends on oxidation reaction time and temperature. These CuO nanostructures have a potential application for nanodevices such as nano gas sensor or dye-sensitized solar cells.

scholarly journals Optimization of Chemical Bath Deposited Mercury Chromium Sulphide Thin Films on Glass Substrate

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
H. B. Patil ◽  
S. V. Borse
Keyword(s):  
Thin Films ◽  
Glass Substrate ◽  
Deposition Time ◽  
Growth Parameters ◽  
Complexing Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Edax Analysis ◽  
Cubic Structure ◽  
Semiconducting Thin Films

Semiconducting thin films of ternary () have been deposited on glass substrate by the simple and economical chemical bath deposition method. We report the deposition and optimization of the solution growth parameters such as temperature, complexing agent, thiourea, and deposition time that maximizes the thickness of the deposited thin film. The X-ray diffraction deposited thin films having cubic structure. The thin films were uniform and adherent to substrate. The composition was found homogeneous and stoichiometric by EDAX analysis.

Preparation and CO2 Gas Sensitive Properties of CuO-SrTiO3-Based Semiconductor Thin Films

2007 ◽  
Vol 280-283 ◽  
pp. 311-314 ◽  
Author(s):  
Yan Fei Gu ◽  
Hui Ming Ji ◽  
Bin Zhang ◽  
Ting Xian Xu
Keyword(s):  
Thin Films ◽  
Chelating Agents ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Good Resistance ◽  
Gas Sensitivity ◽  
X Ray ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Ft Ir

CuO-SrTiO3-based thin films were prepared by novel sol-gel technology on Al2O3 substrates using Cu(NO3)2, SrCl2 and TiCl4 as the starting materials, critic acid and ethylene glycol as chelating agents. CO2 sensing properties of the films were investigated. Structure characteristics of the sol and asgrown thin films were analyzed by FT-IR spectrum, X-ray diffraction and SEM. The results reveal that the films consisted of CuO phase and SrTiO3 phase have nanocrystalline microstructure at 750°C for 40 min. The modified CuO-SrTiO3 thin films exhibit good resistance-temperature and gas sensitivity properties in a wide range of temperature. The films exposed to 6% CO2 show that sensitivity are 32, and response and recover time are within 2 s at 250 °C operating temperature.

Dielectric Properties of Sol-Gel Derived MgAl2O4 Thin Films

2012 ◽  
Vol 151 ◽  
pp. 314-318
Author(s):  
Ching Fang Tseng ◽  
Cheng Hsing Hsu ◽  
Chun Hung Lai
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Dissipation Factor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Preheating Temperature ◽  
Surface Morphologies

This paper describes microstructure characteristics of MgAl2O4 thin films were deposited by sol-gel method with various preheating temperatures and annealing temperatures. Particular attention will be paid to the effects of a thermal treatment in air ambient on the physical properties. The annealed films were characterized using X-ray diffraction. The surface morphologies of treatment film were examined by scanning electron microscopy and atomic force microscopy. At a preheating temperature of 300oC and an annealing temperature of 700oC, the MgAl2O4 films with 9 μm thickness possess a dielectric constant of 9 at 1 kHz and a dissipation factor of 0.18 at 1 kHz.

The Effect of Stabiliser’s Molarity to the Growth of ZnO Nanorods

2011 ◽  
Vol 312-315 ◽  
pp. 99-103 ◽  
Author(s):  
Zuraida Khusaimi ◽  
Mohamad Hafiz Mamat ◽  
Mohd Zainizan Sahdan ◽  
Norbani Abdullah ◽  
Mohamad Rusop
Keyword(s):  
Sol Gel ◽  
Zno Nanorods ◽  
Structural Features ◽  
Zinc Nitrate ◽  
Molar Ratio ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wet Chemical ◽  
Gel Preparation

A wet chemical approach, originating from sol-gel preparation, was adopted with the intention to develop a low-temperature benign method of preparation. ZnO nanorods are successfully grown in an aqueous medium. The precursor, zinc nitrate hexahydrate (Zn(NO3)2.6H2O), is stabilized by hexamethylene tetraamine (HMTA). The effect of changing the molarity of HMTA to the structural orientation of ZnO nanorods is investigated. X-ray diffraction of the synthesized ZnO shows hexagonal zincite structure. The structural features of the nanocrystalline ZnO were studied by SEM. Structural features, surface morphology and differences in lattice orientation are seemingly influenced by varying the Zn2+: HMTA molar ratio. The formation of ZnO nanorods with blunt and sharp tips is found to be significantly affected by this ratio.

SiO2ZrO2 Thin Films as Low Temperature NO2 and O3 Sensors

2015 ◽  
Vol 1088 ◽  
pp. 81-85 ◽  
Author(s):  
T.N. Myasoedova ◽  
Victor V. Petrov ◽  
Nina K. Plugotarenko ◽  
Dmitriy V. Sergeenko ◽  
Galina Yalovega ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Operating Temperatures ◽  
Scanning Electron

Thin SiO2ZrO2films were prepared, up to 0.2 μm thick, by means of the sol–gel technology and characterized by a Scanning electron microscopy and X-ray diffraction. It is shown the presence of monoclinic, cubic and tetragonal phases of ZrO2in the SiO2matrix. The crystallites sizes depend on the annealing temperature of the film and amount to 35 and 56 nm for the films annealed at 773 and 973 K, respectively. The films resistance is rather sensitive to the presence of NO2and O3impurity in air at lower operating temperatures in the range of 30-60°C.

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