Synthesis and characterization of silver oxide nanoparticles prepared by chemical bath deposition for NH3 gas sensing applications

Nano-silver oxide thin films with high sensitivity for NH3 gas were deposited on glass substrates by the chemical bath deposition technique. The preparations were made under different values of pH and deposition time at 70ᵒ C, using silver nitrate AgNO3 and triethanolamine. XRD analysis showed that all thin films werepolycrystalline with several peaks of silver oxides such as Ag2O, AgO and Ag3O4, with an average crystallite size that ranged between 31.7 nm and 45.8 nm, depending on the deposition parameters. Atomic force microscope (AFM) technique illustrated that the films were homogenous with different surface roughness and thegrain size ranged between 55.69 nm and 86.23 nm. The UV-Vis spectrophotometer showed that the optical direct energy gap ranged between 1.66 eV to 2.12 eV. The silver oxide thin film gives a high sensitivity of 70.12 for NH3 gas at 75°C operating temperature. This study shows that different types of silver oxides can beprepared by the CBD techniques, with the nanostructure to be used in gas sensors and optoelectronic applications.

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Synthesis and characterization of ZnS-based quantum dots to trace low concentration of ammonia

Journal of Semiconductors ◽

10.1088/1674-4926/42/12/122901 ◽

2021 ◽

Vol 42 (12) ◽

pp. 122901

Author(s):

Uma Devi Godavarti ◽

P. Nagaraju ◽

Vijayakumar Yelsani ◽

Yamuna Pushukuri ◽

P. S. Reddy ◽

...

Keyword(s):

Quantum Dots ◽

Gas Sensing ◽

High Sensitivity ◽

Average Crystallite Size ◽

Xrd Analysis ◽

Precipitation Method ◽

Zinc Blend ◽

Ammonia Sensing ◽

Sensing Applications ◽

Co Precipitation

Abstract In the present work, a solution-based co-precipitation method has been adopted to synthesize pure and cobalt-doped ZnS quantum dots and characterized by XRD, SEM, TEM with EDX, FTIR and gas sensing properties. XRD analysis has shown a single phase of ZnS quantum dots having a zinc blend structure. TEM and XRD line broadening indicated that the average crystallite size in the sample is in the range of 2 to 5 nm. SEM micrographs show spherical-shaped quantum dots. FTIR studies show that cobalt has been successfully doped into the ZnS cubic lattice. EDX spectra have analyzed the elemental presence in the samples and it is evident that the spectra confirmed the presence of cobalt (Co), zinc (Zn), oxygen (O), and sulphur (S) elements only and no other impurities are observed. The ZnS-based quantum dot sensors reveal high sensitivity towards 50 ppm of ammonia vapors at an operating temperature of 70 °C. Hence, ZnS-based quantum dots can be a promising and quick traceable sensor towards ammonia sensing applications with good response and recovery time.

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Gas-Sensing Property Evaluation of Reactively Sputtered Chromium Oxide Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.55-57.285 ◽

2008 ◽

Vol 55-57 ◽

pp. 285-288 ◽

Cited By ~ 1

Author(s):

C. Oros ◽

Anurat Wisitsoraat ◽

Pichet Limsuwan ◽

M. Horpathum ◽

V. Patthanasettakul ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Metal Oxide ◽

Chromium Oxide ◽

Flow Rate ◽

Gas Sensing ◽

Oxygen Flow Rate ◽

Oxide Thin Film ◽

Oxide Thin Films ◽

Sensing Applications

Metal oxide thin film materials, including SnO2, TiO2, WO3, MoO3, ZnO, have been widely studied for gas sensing applications. However, new gas-sensing materials with distinct and diverse characteristics for new sensing applications such as electronic nose are still being explored. Presently, gas sensing properties of other metal oxides have not yet been extensively explored. Chromium oxide is an interesting metal oxide for gas sensor because of its temperature stability and moderate electrical conductivity. Nevertheless, there have been very few studies on gas sensing behaviors of this material. In this work, chromium oxide thin films were systematically studied by reactive sputtering with varying sputtering parameter including oxygen flow rate. Structural characterization by means of scanning electron microscopy and X-ray diffraction reveals that the films have sub-micometer grain-size with Rhombohedral phase of Cr2O3. Gas-sensing performances of sputtered chromium oxide thin film have been characterized toward ethanol and acetylene sensing. It was found that chromium oxide thin films exhibit p-type conductivity with increased resistance when exposed to ethanol and acetylene, which are reducing gases. In addition, sensitivity to both acetylene and ethanol tend to improve as oxygen flow rate increases. Furthermore, the chromium oxide thin films exhibit high sensitivity at moderate temperature of 250-300 °C with minimum operating temperature of 200 °C.

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Fabrication and Characterization of Polypyrrole/Multi-Walled Carbon Nanotubes Thin Films Using Thermal Evaporation

Polymers ◽

10.3390/polym13224045 ◽

2021 ◽

Vol 13 (22) ◽

pp. 4045

Author(s):

Alaa Attar ◽

Rima D. Alharthy ◽

Mohammed Zwawi ◽

Mohammed Algarni ◽

Faisal Albatati ◽

...

Keyword(s):

Thin Films ◽

Carbon Nanotubes ◽

Thermal Evaporation ◽

Energy Gap ◽

Oxidative Polymerization ◽

Sodium Dodecyl ◽

Average Crystallite Size ◽

Xrd Analysis ◽

Soft Template ◽

Multiwalled Carbon

Polypyrrole/multiwalled carbon nanotubes composites (PPy/MWCNTs) were produced in an acidic solution utilizing an in situ oxidative polymerization method using ferric chloride as an oxidizing agent and sodium dodecyl sulfate as a soft template. Thermal evaporation was used to fabricate thin films from polypyrrole/multiwalled carbon nanotube composites. The resulting composites were examined by different techniques to explore their morphology, structural and electrical characteristics. The surface morphology analysis revealed that polypyrrole structure is a two-dimensional film with impeded nanoparticles and the thickness of coated PPy around the MWCNTs decreases when increasing the amount of MWCNTs. XRD analysis revealed that the average crystallite size of the prepared composites is 62.26 nm. The direct energy gap for PPy is affected by a factor ranging from 2.41 eV to 1.47 eV depending on the contents of MWCNTs. The thin film’s optical properties were examined using experimental and TDDFT-DFT/DMOl3 simulation techniques. The optical constants and optical conductivity of the composites were calculated and correlated. The structural and optical characteristics of the simulated nanocomposites as single isolated molecules accord well with the experimental results. The nanocomposite thin films demonstrated promising results, making them a viable candidate for polymer solar cell demands. Under optimal circumstances, the constructed planar heterojunction solar cells with a 75 ± 3 nm layer of PPy/MWCNTs had a power conversion efficiency (PCE) of 6.86%.

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Optoelectronic properties of highly porous silver oxide thin film

SN Applied Sciences ◽

10.1007/s42452-020-04091-1 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Ahmad Al-Sarraj ◽

Khaled M. Saoud ◽

Abdelaziz Elmel ◽

Said Mansour ◽

Yousef Haik

Keyword(s):

Thin Film ◽

Thin Films ◽

Electron Microscope ◽

Plasma Etching ◽

Silver Oxide ◽

Oxidation Time ◽

Oxide Thin Film ◽

X Ray ◽

Porous Silver ◽

Highly Porous

Abstract In this paper, we report oxidation time effect on highly porous silver oxide nanowires thin films fabricated using ultrasonic spray pyrolysis and oxygen plasma etching method. The NW’s morphological, electrical, and optical properties were investigated under different plasma etching periods and the number of deposition cycles. The increase of plasma etching and oxidation time increases the surface roughness of the Ag NWs until it fused to form a porous thin film of silver oxide. AgNWs based thin films were characterized using X-ray diffraction, scanning electron microscope, transmission electron microscope, X-ray photoemission spectroscopy, and UV–Vis spectroscopy techniques. The obtained results indicate the formation of mixed mesoporous Ag2O and AgO NW thin films. The Ag2O phase of silver oxide appears after 300 s of oxidation under the same conditions, while the optical transparency of the thin film decreases as plasma etching time increases. The sheet resistance of the final film is influenced by the oxidation time and the plasma application periodicity. Graphic abstract

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Properties of pulsed laser deposited nanocomposite NiO:Au thin films for gas sensing applications

Applied Physics A ◽

10.1007/s00339-012-6816-7 ◽

2012 ◽

Vol 107 (4) ◽

pp. 899-904 ◽

Cited By ~ 13

Author(s):

I. Fasaki ◽

M. Kandyla ◽

M. Kompitsas

Keyword(s):

Thin Films ◽

Gas Sensing ◽

Pulsed Laser ◽

Sensing Applications

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Polyaniline/SnO2 Nanocomposite Sensor for NO2 Gas Sensing at Low Operating Temperature

International Journal of Nanoscience ◽

10.1142/s0219581x15500118 ◽

2015 ◽

Vol 14 (04) ◽

pp. 1550011 ◽

Cited By ~ 8

Author(s):

A. Sharma ◽

M. Tomar ◽

V. Gupta ◽

A. Badola ◽

N. Goswami

Keyword(s):

Thin Films ◽

Gas Sensing ◽

High Sensitivity ◽

Morphological Properties ◽

X Ray Diffraction ◽

Chemical Route ◽

Sensing Properties ◽

Response Recovery ◽

Transmission Electron ◽

Gas Sensing Properties

In this paper gas sensing properties of 0.5–3% polyaniline (PAni) doped SnO 2 thin films sensors prepared by chemical route have been studied towards the trace level detection of NO 2 gas. The structural, optical and surface morphological properties of the PAni doped SnO 2 thin films were investigated by performing X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Raman spectroscopy measurements. A good correlation has been identified between the microstructural and gas sensing properties of these prepared sensors. Out of these films, 1% PAni doped SnO 2 sensor showed high sensitivity towards NO 2 gas along with a sensitivity of 3.01 × 102 at 40°C for 10 ppm of gas. On exposure to NO 2 gas, resistance of all sensors increased to a large extent, even greater than three orders of magnitude. These changes in resistance upon removal of NO 2 gas are found to be reversible in nature and the prepared composite film sensors showed good sensitivity with relatively faster response/recovery speeds.

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MWCNT Devices Fabricated by Dielectrophoresis: Study of Their Electrical Behavior Related to Deposited Nanotube Amount for Gas Sensing Applications

Journal of Integrated Circuits and Systems ◽

10.29292/jics.v10i1.400 ◽

2015 ◽

Vol 10 (1) ◽

pp. 13-20

Author(s):

Elisabete Galeazzo ◽

Marcos C. Moraes ◽

Henrique E. M. Peres ◽

Michel O. S. Dantas ◽

Victor G. C. Lobo ◽

...

Keyword(s):

Carbon Nanotubes ◽

Gas Sensing ◽

High Sensitivity ◽

Cost Effective ◽

Adsorbed Water ◽

Fast Response ◽

Process Time ◽

Electrical Behavior ◽

Glass Substrates ◽

Sensing Applications

Intensive research has been focused on investigating new sensing materials, such as carbon nanotubes (CNT) because of their promising characteristics. However, there are challenges related to their application in commercial devices such as sensitivity, compatibility, and complexity of miniaturization, among others. We report the study of the electrical behavior of devices composed by multi-walled carbon nanotubes (MWCNT) deposited between aluminum electrodes on glass substrates by means of dielectrophoresis (DEP), which is a simple and cost-effective method. The devices were fabricated by varying the DEP process time. Remarkable changes in their electric resistance were noticed depending on the MWCNT quantities deposited. Other electrical properties of devices such as high sensitivity, fast response time and stability are also characterized in humid environment. A humidity sensing mechanism is proposed on the basis of charge transfer between adsorbed water molecules and the MWNTC surface or between water and the glass surface.

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Developing GLAD Parameters to Control the Deposition of Nanostructured Thin Film

Sensors ◽

10.3390/s22020651 ◽

2022 ◽

Vol 22 (2) ◽

pp. 651

Author(s):

Jakub Bronicki ◽

Dominik Grochala ◽

Artur Rydosz

Keyword(s):

Thin Films ◽

Gas Sensing ◽

Glancing Angle Deposition ◽

Metal Oxide Thin Films ◽

Nanostructured Thin Film ◽

Sensing Applications ◽

Deposition Parameters ◽

Glancing Angle ◽

Glad Technique ◽

Relative Errors

In this paper, we describe the device developed to control the deposition parameters to manage the glancing angle deposition (GLAD) process of metal-oxide thin films for gas-sensing applications. The GLAD technique is based on a set of parameters such as the tilt, rotation, and substrate temperature. All parameters are crucial to control the deposition of nanostructured thin films. Therefore, the developed GLAD controller enables the control of all parameters by the scientist during the deposition. Additionally, commercially available vacuum components were used, including a three-axis manipulator. High-precision readings were tested, where the relative errors calculated using the parameters provided by the manufacturer were 1.5% and 1.9% for left and right directions, respectively. However, thanks to the formula developed by our team, the values were decreased to 0.8% and 0.69%, respectively.

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Preparation and Gas-Sensing Property of Coppertetra-Iso-Propoxyphthalocyanine Spin-Coating Film

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.197-198.1735 ◽

2011 ◽

Vol 197-198 ◽

pp. 1735-1738

Author(s):

Qiang Li ◽

Li Hua Huo ◽

Shan Gao ◽

Xiao Juan Qi ◽

Hui Zhao

Keyword(s):

Thin Films ◽

Spin Coating ◽

Gas Sensing ◽

High Sensitivity ◽

Coating Film ◽

Gas Sensing Properties ◽

Response And Recovery ◽

Ft Ir ◽

Spinning Speed ◽

Spectroscopy Property

The thin films of copper 2, 9, 16, 23-tetra-iso-propoxy phthalocyanine (i-pro-CuPc) were prepared by spin-coating technique. The surface morphology and spectroscopy property of the thin films were characterized by AFM, UV-Vis and FT-IR spectra. The results show that good films can be obtained under certain spinning speed. The gas-sensing properties of the multilayers to three alcohols gas were measured at room temperature. The spin-coating thin films exhibited high sensitivity and rapid response- recovery characteristics to these gases. The response and recovery time of the thin films to 30*10-6 v/v of C2H5OH vapor is only 28 s and 55 s, respectively.

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