Ammonia Gas Detection Using Fabricated Zinc Oxide (ZnO) Nanoparticles on Glass Tube Substrates

2018 ◽  
Vol 775 ◽  
pp. 266-271 ◽  
Author(s):  
Kurt Brian Daine B. Punzalan ◽  
Franz Kevin B. Manalo ◽  
Emmanuel A. Florido
Keyword(s):  
Zinc Oxide ◽  
Gas Sensing ◽  
Linear Trend ◽  
Glass Tube ◽  
Ammonium Hydroxide ◽  
Zno Films ◽  
Ammonia Gas ◽  
Layer Adsorption ◽  
Different Temperatures ◽  
Silar Technique

This study aimed to determine the ammonia (NH3) gas sensing ability of zinc oxide (ZnO) films deposited on glass tube substrates via successive ionic layer adsorption and reaction (SILAR) technique. The fabricated films were annealed at different temperatures. The sensor films were exposed to different volumes of ammonium hydroxide (NH4OH), converted to parts per million (ppm). The change in voltage from concentrations 595ppm up to 1189ppm exhibited a linear trend. However, no trend was revealed in concentrations 2378ppm and 3964ppm due to film saturation. Results showed that the films annealed at 250 °C, 300 °C, 350 °C, and 400 °C presented sensitivities of 2.7×10-4V/ppm, 1.0×10-4V/ppm, 2.3×10-4V/ppm, and 1.5×10-4V/ppm with R2values of 0.997, 0.994, 0.904, 0.999 and resolutions of 3.7 ppm/mV, 9.9 ppm/mV, 4.4 ppm/mV, and 6.6 ppm/mV, respectively. Furthermore, this research study had proven that high quality gas sensors may be fabricated at a lower cost.

scholarly journals Nanostructured ZnO/Ag Film Prepared by Magnetron Sputtering Method for Fast Response of Ammonia Gas Detection

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1899 ◽  
Author(s):  
Yiran Zheng ◽  
Min Li ◽  
Xiaoyan Wen ◽  
Ho-Pui Ho ◽  
Haifei Lu
Keyword(s):  
Magnetron Sputtering ◽  
Thermal Annealing ◽  
Physical Vapor Deposition ◽  
Gas Sensing ◽  
Volume Ratio ◽  
Fast Response ◽  
Gas Detection ◽  
Zno Films ◽  
Zno Film ◽  
Ammonia Gas

Possessing a large surface-to-volume ratio is significant to the sensitive gas detection of semiconductor nanostructures. Here, we propose a fast-response ammonia gas sensor based on porous nanostructured zinc oxide (ZnO) film, which is fabricated through physical vapor deposition and subsequent thermal annealing. In general, an extremely thin silver (Ag) layer (1, 3, 5 nm) and a 100 nm ZnO film are sequentially deposited on the SiO2/Si substrate by a magnetron sputtering method. The porous nanostructure of ZnO film is formed after thermal annealing contributed by the diffusion of Ag among ZnO crystal grains and the expansion of the ZnO film. Different thicknesses of the Ag layer help the formation of different sizes and quantities of hollows uniformly distributed in the ZnO film, which is demonstrated to hold superior gas sensing abilities than the compact ZnO film. The responses of the different porous ZnO films were also investigated in the ammonia concentration range of 10 to 300 ppm. Experimental results demonstrate that the ZnO/Ag(3 nm) sensor possesses a good electrical resistance variation of 85.74% after exposing the sample to 300 ppm ammonia gas for 310 s. Interestingly, a fast response of 61.18% in 60 s for 300 ppm ammonia gas has been achieved from the ZnO/Ag(5 nm) sensor, which costs only 6 s for the response increase to 10%. Therefore, this controllable, porous, nanostructured ZnO film maintaining a sensitive gas response, fabricated by the physical deposition approach, will be of great interest to the gas-sensing community.

scholarly journals The Role of ALD-ZnO Seed Layers in the Growth of ZnO Nanorods for Hydrogen Sensing

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 491 ◽  
Author(s):  
Yangming Lu ◽  
Chiafen Hsieh ◽  
Guanci Su
Keyword(s):  
Zinc Oxide ◽  
Surface Area ◽  
Gas Sensing ◽  
Zno Nanorods ◽  
Clean Energy ◽  
Hydrogen Sensor ◽  
Zno Films ◽  
Hydrogen Sensing ◽  
Highly Sensitive ◽  
Seed Layers

Hydrogen is one of the most important clean energy sources of the future. Because of its flammability, explosiveness, and flammability, it is important to develop a highly sensitive hydrogen sensor. Among many gas sensing materials, zinc oxide has excellent sensing properties and is therefore attracting attention. Effectively reducing the resistance of sensing materials and increasing the surface area of materials is an important issue to increase the sensitivity of gas sensing. Zinc oxide seed layers were prepared by atomic layer deposition (ALD) to facilitate the subsequent hydrothermal growth of ZnO nanorods. The nanorods are used as highly sensitive materials for sensing hydrogen due to their inherent properties as oxide semiconductors and their very high surface areas. The low resistance value of ALD-ZnO helps to transport electrons when sensing hydrogen gas and improves the sensitivity of hydrogen sensors. The large surface area of ZnO nanorods also provides lots of sites of gas adsorption which also increases the sensitivity of the hydrogen sensor. Our experimental results show that perfect crystallinity helped to reduce the electrical resistance of ALD-ZnO films. High areal nucleation density and sufficient inter-rod space were determining factors for efficient hydrogen sensing. The sensitivity increased with increasing hydrogen temperature, from 1.03 at 225 °C, to 1.32 at 380 °C after sensing 100 s in 10,000 ppm of hydrogen. We discuss in detail the properties of electrical conductivity, point defects, and crystal quality of ALD-ZnO films and their probable effects on the sensitivity of hydrogen sensing.

Impact of Deposition Temperature on Amorphous Zinc Oxide Thin Film Characteristics

2021 ◽  
Vol 12 (5) ◽  
pp. 806-813
Author(s):  
Omprakash S S ◽  
Naveen Kumar S K
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Thin Film Transistor ◽  
Oxide Thin Film ◽  
Zno Films ◽  
Sem Images ◽  
Structural Morphology ◽  
Different Temperatures ◽  
Optical Profilometer ◽  
Pyrolysis Unit

In this paper, we discuss the deposition of amorphous zinc oxide (a: ZnO) thin film at two different temperatures by spray pyrolysis unit for Thin Film Transistor (TFT) application. The a: ZnO films were studied for its structural, morphology, composition, optical and electrical properties by means of XRD, SEM, EDAX, UV-Visible spectroscopy and I-V measurement system respectively. The film thickness characterized by optical Profilometer. The SEM images exhibit the variation in temperature leads to the crystallinity of the film. The XRD spectrum confirmed the films were amorphous in nature.

Application of Modified PANI-ZnO Composites for NH3Gas Sensor at Ambient Temperature

2020 ◽  
Vol 42 (3) ◽  
pp. 390-390
Author(s):  
Naimat Ullah Naimat Ullah ◽  
Anwar Ul Haq Ali Shah Anwar Ul Haq Ali Shah ◽  
Fazal Akbar Jan Fazal Akbar Jan ◽  
Rotaba Ansir Rotaba Ansir ◽  
Wali Muhammad Wali Muhammad
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Ambient Temperature ◽  
Zinc Oxide Nanoparticles ◽  
Gas Sensing ◽  
Visible Spectrum ◽  
Xrd Analysis ◽  
Oxide Nanoparticles ◽  
Ammonia Gas ◽  
Uv Visible

Polyaniline and zinc oxide nanoparticles were successfully synthesized through inverse emulsion polymerization method and hydrothermal method respectively. For ammonia gas sensing using LCR meter thin film of the composite was fabricated by using spin coater. The functional groups, morphological, optical, structural properties of zinc oxide nanoparticles, polyaniline (emeraldine salt) and composites were investigated by FTIR spectroscopy, Scanning electron microscopy (SEM), UV- Visible spectroscopy and XRD analysis. The formation of ZnO particles of different shapes in the nano range was confirmed from UV-visible and XRD analysis. UV visible spectrum shows the formation of nanoparticles of ZnO. Thin film of Polyaniline/zinc oxide composites were deposited on the surface of copper interdigitated electrode. The fabricated device showed sensitivity to ammonia gas (NH3) at ambient temperature (300 K). It was observed that the resistance is decreases with the increase of volume of ammonia gas. The electrical properties were also investigated of the different concentration of nanocomposite. Optimum sensing response was achieved with PANI in the presence of 50 wt% ZnO nanoparticles. It may also be inferred from this study that the solution mixing process to produce composites has promising future if handled carefully.

scholarly journals AZO-Based ZnO Nanosheet MEMS Sensor with Different Al Concentrations for Enhanced H2S Gas Sensing

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3377
Author(s):  
Yempati Nagarjuna ◽  
Jun-Cong Lin ◽  
Sheng-Chang Wang ◽  
Wen-Tse Hsiao ◽  
Yu-Jen Hsiao
Keyword(s):  
Zinc Oxide ◽  
Gas Sensing ◽  
Growth Time ◽  
Optimal Conditions ◽  
Gas Concentration ◽  
Zno Nanostructure ◽  
Mems Sensor ◽  
Different Temperatures ◽  
Micro Electromechanical System ◽  
Different Gases

The properties of H2S gas sensing were investigated using a ZnO nanostructure prepared with AZO (zinc oxide with aluminium) and Al surfaces which were developed on a MEMS (Micro Electromechanical System) device. Hydrothermal synthesis was implemented for the deposition of the ZnO nanostructure. To find the optimal conditions for H2S gas sensing, different ZnO growth times and different temperatures were considered and tested, and the results were analysed. At 250 °C and 90 min growth time, a ZnO sensor prepared with AZO and 40 nm Al recorded an 8.5% H2S gas-sensing response at a 200 ppb gas concentration and a 14% sensing response at a gas concentration of 1000 ppb. The dominant sensing response provided the optimal conditions for the ZnO sensor, which were 250 °C temperature and 90 min growth time. Gas sensor selectivity was tested with five different gases (CO, SO2, NO2, NH3 and H2S) and the sensor showed great selectivity towards H2S gas.

Deposition and characterization of ultrathin intrinsic zinc oxide (i-ZnO) films by radio frequency (RF) sputtering for propane gas sensing application

2018 ◽  
Vol 29 (18) ◽  
pp. 15682-15692 ◽  
Author(s):  
G. Regmi ◽  
M. Rohini ◽  
P. Reyes-Figueroa ◽  
Arturo Maldonado ◽  
María de la Luz Olvera ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Radio Frequency ◽  
Gas Sensing ◽  
Rf Sputtering ◽  
Zno Films ◽  
Sensing Application

Analysis of Sputtered Zinc Oxide Films

1980 ◽  
Vol 38 ◽  
pp. 416-417
Author(s):  
T. A. Emma ◽  
M. P. Singh
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Piezoelectric Materials ◽  
Oxide Films ◽  
Optical Quality ◽  
Zno Films ◽  
Rf Power ◽  
X Ray Diffraction ◽  
Sputtered Films ◽  
Zinc Oxide Films

Optical quality zinc oxide films have been characterized using reflection electron diffraction (RED), replication electron microscopy (REM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Significant microstructural differences were observed between rf sputtered films and planar magnetron rf sputtered films. Piezoelectric materials have been attractive for applications to integrated optics since they provide an active medium for signal processing. Among the desirable physical characteristics of sputtered ZnO films used for this and related applications are a highly preferred crystallographic texture and relatively smooth surfaces. It has been found that these characteristics are very sensitive to the type and condition of the substrate and to the several sputtering parameters: target, rf power, gas composition and substrate temperature.

Sign in / Sign up

Export Citation Format

Share Document