SYNTHESIS AND ETHANOL SENSING CHARACTERISTICS OF NANOSTRUCTURED MoO3:Zn THIN FILMS

2018 ◽  
Vol 25 (01) ◽  
pp. 1850046 ◽  
Author(s):  
SEYYED HAMID MOUSAVI-ZADEH ◽  
MOHAMMAD BAGHER RAHMANI
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Molybdenum Trioxide ◽  
Low Cost ◽  
Ethanol Vapor ◽  
Glass Substrates ◽  
Structure Changes ◽  
Recovery Times ◽  
Different Temperatures ◽  
Sensing Characteristics

In this research, gas sensing characteristics of undoped and zinc-doped molybdenum trioxide (MoO[Formula: see text] thin films toward ethanol vapor were investigated. Thin films were deposited using low cost and simple technique of spray pyrolysis on top of glass substrates at 450[Formula: see text]C. Effects of addition of Zn, as an impurity, on the surface morphology, structural and optical properties of MoO3 thin films were also investigated. X-ray diffraction (XRD) pattern analysis showed that by increasing the amount of impurity, crystal structure changes from orthorhombic [Formula: see text]-MoO3 to two new phases of monoclinic [Formula: see text]-ZnMoO4 and Mo5O[Formula: see text] reduced phase. Field emission scanning electron microscope (FESEM) images showed that by increasing the amount of impurity up to 5[Formula: see text]at.%, grain sizes decrease to about 60[Formula: see text]nm. UV–Vis analysis showed that by increasing the percentage of impurity the band gap of thin films increases. Gas sensing properties of samples were studied at three temperatures of 200[Formula: see text]C, 250[Formula: see text]C and 300[Formula: see text]C toward different concentrations of ethanol vapor. Gas response of 5[Formula: see text]at.% Zn-doped MoO3 thin film reached the maximum value of [Formula: see text]% when it exposed to 1000[Formula: see text]ppm of ethanol vapor. Response and recovery times for all samples were reported at different temperatures.

scholarly journals Comparative NO2 Sensing Characteristics of SnO2:WO3 Thin Film Against Bulk and Investigation of Optical Properties of the Thin Film

2018 ◽  
Vol 15 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Gas Sensing ◽  
Comparative Investigation ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Thin Film Sensors ◽  
Gas Sensing Properties ◽  
Evaporation Technique ◽  
Sensing Characteristics

A comparative investigation of gas sensing properties of SnO2 doped with WO3 based on thin film and bulk forms was achieved. Thin films were deposited by thermal evaporation technique on glass substrates. Bulk sensors in the shape of pellets were prepared by pressing SnO2:WO3 powder. The polycrystalline nature of the obtained films with tetragonal structure was confirmed by X-ray diffraction. The calculated crystalline size was 52.43 nm. Thickness of the prepared films was found 134 nm. The optical characteristics of the thin films were studied by using UV-VIS Spectrophotometer in the wavelength range 200 nm to 1100 nm, the energy band gap, extinction coefficient and refractive index of the thin film were 2.5 eV , 0.024 and 2.51, respectively. Hall measurements confirmed that the films are n-type. The NO2 sensing characteristics of the SnO2:WO3 sensors were studied with various temperatures and NO2 gas concentrations. Both thin film and bulk sensors showed maximum sensitivity at temperature of 250 oC. Thin film sensors showed enhanced response in comparison to that of pellets.

Screen-Printed Fe2O3/ZnO thick films for gas sensing applications

2005 ◽  
Vol 2 (1) ◽  
pp. 25-39 ◽  
Author(s):  
K. Arshak ◽  
I. Gaidan ◽  
L. Cavanagh
Keyword(s):  
Gas Sensing ◽  
Response Times ◽  
Thick Films ◽  
Ethanol Vapor ◽  
Vapor Concentration ◽  
Resistance Change ◽  
Glass Substrates ◽  
Sensing Applications ◽  
Recovery Times ◽  
Composition Ratios

This paper investigates iron-oxide and zinc-oxide thick-films for gas sensing applications. The films were printed onto glass substrates with silver electrodes. The effects of propanol, methanol and ethanol vapor on the devices at room temperature (in the concentration range 500–2000ppm) were investigated. The percentage relative resistance change, ΔR = ((Rgas − Rair)/Rair) ×100, was seen to increase linearly with increasing gas vapor concentration. The sensitivity of the films to the gas vapor was determined from the slope of the graphs. It was observed that various film compositions showed a higher sensitivity to propanol than to methanol and ethanol. Moreover, the sensitivity to propanol increased from 0.077 to 0.166 to 0.173%/ppm for the three samples with molecular weight composition ratios of: 90%/10%, 80/20% and 70%/30% of Fe2O3 to ZnO respectively. The response times of sensors 1, 2 and 3 (to 1000ppm step changes in propanol concentration) were 48.6 seconds, 86.4 seconds and 76.5 seconds, while the recovery times were 117 seconds, 186 seconds and 153 seconds respectively.

Thermal conversion of CBD grown ZnS thin films to ZnO

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kooliyankal Naseema ◽  
Kaniyamkandy Ribin ◽  
Nidiyanga Navya ◽  
Prasoon Prasannan
Keyword(s):  
Thin Films ◽  
Low Cost ◽  
Thermal Conversion ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Glass Substrates ◽  
Anion Substitution ◽  
Nano Crystalline ◽  
Before And After ◽  
Uv Visible

AbstractNano crystalline zinc sulfide thin films were deposited onto glass substrates by chemical bath deposition method. One of the samples was annealed at 300 °C for 2 h in air using a muffle furnace. The prepared thin films were investigated by X-ray diffraction (XRD), UV–visible spectroscopy (UV–vis), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM) and Raman spectroscopy (FT-R) studies before and after annealing. The analysis confirmed the thermal-induced anion substitution and conversion of ZnS crystal to ZnO wurtzite crystal. XRD pattern showed that these films were phase pure and polycrystalline in nature. Optical band gap was found to be 3.86 eV for ZnS and 3.21 eV for ZnO. The films prepared by this simple, low-cost technique are suitable for photovoltaic and optoelectronic applications.

Direct Writing on Paper Substrate to Prepare Silver Electrode Structures for Flexible Sensors

2021 ◽  
Vol 21 (12) ◽  
pp. 6048-6053
Author(s):  
Qi Wang ◽  
Mingwei Li ◽  
Yao Xie ◽  
Yun Ou ◽  
Weiping Zhou
Keyword(s):  
Low Cost ◽  
Rapid Development ◽  
Silver Electrode ◽  
Silver Nanostructures ◽  
Direct Writing ◽  
Paper Substrate ◽  
Electronic Products ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Writing Technology

With the rapid development of the electronics industry, electronic products based on silicon and glass substrates electronic products will gradually be unable to meet the rising demand. Flexibility, environmental protection, and low costs are important for the development of electronic products. In this study, an efficient and low-cost method for preparing silver electrode structures by direct writing on paper has been demonstrated. Based on this method, a flexible paper-based sensor was prepared. The liquid printing ink used mainly comprises a precursor liquid without pre-prepared nanomaterials. The precursor liquid is transparent with good fluidity. Simple direct writing technology was used to write on the paper substrate using the precursor ink. When the direct-writing paper substrate was subsequently heated, silver nanostructures precipitated from the precursor liquid ink onto the paper substrate. The effect of different temperatures on the formation of the silver nanostructures and the influence of different direct writing processes on the structures were studied. Finally, a paper-based flexible sensor was prepared for finger-bending signal detection. The method is simple to operate and low in cost and can be used for the preparation of environment-friendly paper-based devices.

CuxSbySz THIN FILMS PRODUCED BY ANNEALING CHEMICALLY DEPOSITED Sb2S3-CuS THIN FILMS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 667-670 ◽  
Author(s):  
Y. RODRÍGUEZ-LAZCANO ◽  
M. T. S. NAIR ◽  
P. K. NAIR
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Band Gap ◽  
Deposition Method ◽  
Photovoltaic Devices ◽  
Large Area ◽  
Electrical And Optical Properties ◽  
Ternary Compounds ◽  
Glass Substrates ◽  
Different Temperatures

The possibility of generating ternary compounds through annealing thin film stacks of binary composition has been demonstrated before. In this work we report a method to produce large area coating of ternary compounds through a reaction in solid state between thin films of Sb2S3 and CuS. Thin films of Sb2S3 -CuS were deposited on glass substrates in the sequence of Sb2S3 followed by CuS (on Sb2S3 ) using chemical bath deposition method. The multilayer stack, thus produced, of approximately 0.5 μm in thickness, where annealed under nitrogen and argon atmospheres at different temperatures to produce films of ternary composition, CuxSbySz . An optical band gap of ~1.5 eV was observed in these films, suggesting that the thin films of ternary composition formed in this way are suitable for use as absorber materials in photovoltaic devices. The results on the analyses of structural, electrical and optical properties of films formed with different combinations of thickness in the multilayers will be discussed in the paper.

scholarly journals Residual Oxygen Effects on the Properties of MoS2 Thin Films Deposited at Different Temperatures by Magnetron Sputtering

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1183
Author(s):  
Peiyu Wang ◽  
Xin Wang ◽  
Fengyin Tan ◽  
Ronghua Zhang
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Magnetron Sputtering ◽  
Deposition Rate ◽  
Deposition Temperature ◽  
Energy Dispersive Spectrometer ◽  
Rf Magnetron Sputtering ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Oxygen Atoms

Molybdenum disulfide (MoS2) thin films were deposited at different temperatures (150 °C, 225 °C, 300 °C, 375 °C, and 450 °C) on quartz glass substrates and silicon substrates using the RF magnetron sputtering method. The influence of deposition temperature on the structural, optical, electrical properties and deposition rate of the obtained thin films was investigated by X-ray diffraction (XRD), Energy Dispersive Spectrometer (EDS), Raman, absorption and transmission spectroscopies, a resistivity-measuring instrument with the four-probe method, and a step profiler. It was found that the MoS2 thin films deposited at the temperatures of 150 °C, 225 °C, and 300 °C were of polycrystalline with a (101) preferred orientation. With increasing deposition temperatures from 150 °C to 300 °C, the crystallization quality of the MoS2 thin films was improved, the Raman vibrational modes were strengthened, the deposition rate decreased, and the optical transmission and bandgap increased. When the deposition temperature increased to above 375 °C, the molecular atoms were partially combined with oxygen atoms to form MoO3 thin film, which caused significant changes in the structural, optical, and electrical properties of the obtained thin films. Therefore, it was necessary to control the deposition temperature and reduce the contamination of oxygen atoms throughout the magnetron sputtering process.

scholarly journals Optical and Electrical Properties of Thin Films of CuS Nanodisks Ensembles Annealed in a Vacuum and Their Photocatalytic Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. Santos Cruz ◽  
S. A. Mayén Hernández ◽  
F. Paraguay Delgado ◽  
O. Zelaya Angel ◽  
R. Castanedo Pérez ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hydrogen Peroxide ◽  
Photocatalytic Activity ◽  
Electrical Properties ◽  
Absolute Temperature ◽  
Glass Substrates ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Blue Solution

Effects on the optical, electrical, and photocatalytic properties of undoped CuS thin films nanodisks vacuum annealed at different temperatures were investigated. The chemical bath prepared CuS thin films were obtained at 40°C on glass substrates. The grain size of13.5±3.5 nm was computed directly from high-resolution transmission electron microscopy (HRTEM) images. The electrical properties were measured by means of both Hall effect at room temperature and dark resistivity as a function of the absolute temperature 100–330 K. The activation energy values were calculated as 0.007, 0.013, and 0.013 eV for 100, 150, and 200°C, respectively. The energy band gap of the films varied in the range of 1.98 up to 2.34 eV. The photocatalytic activity of the CuS thin film was evaluated by employing the degradation of aqueous methylene blue solution in the presence of hydrogen peroxide. The CuS sample thin film annealed in vacuum at 150°C exhibited the highest photocatalytic activity in presence of hydrogen peroxide.

scholarly journals Characterization of Electrodeposited Cadmium Selenide Thin Films

2012 ◽  
Vol 60 (1) ◽  
pp. 137-140 ◽  
Author(s):  
RI Chowdhury ◽  
MS Islam ◽  
F Sabeth ◽  
G Mustafa ◽  
SFU Farhad ◽  
...  
Keyword(s):  
Thin Films ◽  
Cadmium Selenide ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Cdse Film ◽  
Cell Structures ◽  
Deposited Film ◽  
Deposited Films

Cadmium selenide (CdSe) thin films have been deposited on glass/conducting glass substrates using low-cost electrodeposition method. X-ray diffraction (XRD) technique has been used to identify the phases present in the deposited films and observed that the deposited films are mainly consisting of CdSe phases. The photoelectrochemical (PEC) cell measurements indicate that the CdSe films are n-type in electrical conduction, and optical absorption measurements show that the bandgap for as-deposited film is estimated to be 2.1 eV. Upon heat treatment at 723 K for 30 min in air the band gap of CdSe film is decreased to 1.8 eV. The surface morphology of the deposited films has been characterized using scanning electron microscopy (SEM) and observed that very homogeneous and uniform CdSe film is grown onto FTO/glass substrate. The aim of this work is to use n-type CdSe window materials in CdTe based solar cell structures. The results will be presented in this paper in the light of observed data.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10352  Dhaka Univ. J. Sci. 60(1): 137-140 2012 (January)

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