Thin film combustible gas sensors based on Zinc Oxide

2001 ◽  
Vol 666 ◽  
Author(s):  
Patrícia Nunes ◽  
Elvira Fortunato
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Zinc Oxide ◽  
Gas Sensors ◽  
Operating Temperature ◽  
Zno Thin Films ◽  
Gas Concentration ◽  
High Electrical Resistivity ◽  
Combustible Gas ◽  
Sensitivity Tests

ABSTRACTSensitivity tests to reductive gases such as methane, hydrogen and ethane were performed on zinc oxide (ZnO) thin films. The highest value of sensitivity was obtained for the film with a high electrical resistivity and a low thickness. The variation of the operating temperature of the film leads to a significant change in the sensitivity of the sensor with an ideal operating temperature dependence of the gas used. The sensitivity of the ZnO thin films changes linear with the increase of the gas concentration. However these films seem to be more appropriated for the detection of hydrogen following by methane and than for ethane since the value of sensitivity obtained are higher and its variation with the gas concentration more pronounced.

Silver Doped Zinc Oxide Thin Film Production by Thermionic Vacuum Arc (TVA) Technique

2021 ◽  
Vol 43 (3) ◽  
pp. 253-253
Author(s):  
Mehmet zkan Mehmet zkan ◽  
Sercen Sadik Erdem Sercen Sadik Erdem
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Zinc Oxide ◽  
Band Gap ◽  
Glass Substrate ◽  
Zno Thin Films ◽  
Vacuum Arc ◽  
Zno Thin Film ◽  
Doped Zno ◽  
Thermionic Vacuum Arc

In this paper, silver (Ag)doped Zinc Oxide(ZnO) thin films were prepared on glass and silicon substrate by using a thermionic vacuum arc technique. The surface, structural, optical characteristics of silver doped thin films have been examined by X-Ray diffractometer (XRD), field emission scanning emission electron microscopy (FESEM), atomic force microscopy (AFM), and UV-Visible spectrophotometer. As a result of these measurements, Ag, Zn and ZnO reflection planes were determined for thin films formed on Si and glass substrate. Nano crystallites have emerged in FESEM and AFM images. The produced films have low transparency. The optical band gap values were measured by photoluminescence devices at room temperature for thin films produced on silicon and glass substrate. The band gap values are very close to 3.10 eV for Ag doped ZnO thin films. The band gap of un-doped ZnO thin film is approximately 3.3 eV. It was identified that Ag doped changes the properties of the ZnO thin film.

Multifunctional zinc oxide thin films for high-performance UV photodetectors and nitrogen dioxide gas sensors

RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 25641-25650 ◽  
Author(s):  
S. K. Shaikh ◽  
V. V. Ganbavle ◽  
S. I. Inamdar ◽  
K. Y. Rajpure
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Zinc Oxide ◽  
Nitrogen Dioxide ◽  
Gas Sensor ◽  
Gas Sensors ◽  
High Performance ◽  
Zno Thin Film ◽  
Uv Photodetector ◽  
Uv Photodetectors

Multifunctional use of ZnO thin film as NO2 gas sensor and UV photodetector.

Decoration of Gold Nanoparticles on TiO2 Thin Films for Enhanced Response of Ethanol Gas Sensors

2014 ◽  
Vol 979 ◽  
pp. 251-254 ◽  
Author(s):  
Benjarong Samransuksamer ◽  
Mati Horprathum ◽  
Pitak Eiamchai ◽  
Viyapol Patthanasettakul ◽  
Anurat Wisitsoraat ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensors ◽  
Au Nanoparticles ◽  
Operating Temperature ◽  
Element Composition ◽  
Dc Magnetron Sputtering ◽  
Au Nps ◽  
X Ray ◽  
Gas Concentration ◽  
Average Size

This work investigated the decoration of the gold (Au) nanoparticles (NPs) on the TiO2 thin films for the applications in ethanol gas sensors. The Au-decorated TiO2 thin films (Au-TiO2) were prepared by the DC magnetron sputtering on the silicon (100) wafers and alumina substrates, interdigitated with Au electrodes. The distribution and size of Au nanoparticles were controlled by varying the sputtering time. Morphologies and element composition of the Au-TiO2 films were examined by field-emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX) respectively. The FE-SEM micrographs when the sputtering time was increased, the average size of the Au NPs was also increased. On the other hand, the distribution of the Au NPs was decreased. The change in size and distribution of the Au NPs consequently improved the response of ethanol gas sensors. The prepared Au-TiO2 was tested, in comparison with TiO2 reference films, as the ethanol sensors at 250-350oC in 50-1,000 ppm gas concentration. The results showed that the TiO2 thin film with Au-decorated at 6 sec sputtering time yielded the highest response of 514 at 350oC operating temperature and 1,000 ppm gas concentration.

Working Pressure Dependence of Structure and Optical Performance of Zinc Oxide Thin Films by Magnetron Sputtering

2013 ◽  
Vol 734-737 ◽  
pp. 2572-2575 ◽  
Author(s):  
S.B. Chen ◽  
Z.Y. Zhong
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Zinc Oxide ◽  
Magnetron Sputtering ◽  
Energy Gap ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Optical Performance ◽  
Optical Energy Gap ◽  
Working Pressure

Zinc oxide (ZnO) thin films were grown by magnetron sputtering onto glass substrates employing a sintered ceramic target and pure argon gas. The influence of working pressure on structure and optical performance of the thin films were studied by the measurements of X-ray diffraction (XRD) patterns and optical transmission spectra. The optical energy gap of the ZnO thin film were calculated according to the Taucs law. The results demonstrate that all the ZnO thin films have preferred orientation along (002) direction. The working pressure affects not only the structure parameters such as lattice constant, strain and stress in the plane of the film, but also the optical transmittance and energy gap of the ZnO thin films. The ZnO thin film deposited at the working pressure of 0.5 Pa exhibits the maximum average visible transmittance of 86.6%, a compressive stress of 1.72×109 Pa, and an optical energy gap of 3.273 eV.

scholarly journals Structural behavior of DC sputtered zinc oxide (ZnO) Thin films

2020 ◽  
Vol 1664 ◽  
pp. 012004
Author(s):  
Abbas Sabah Shaker ◽  
Abdalhussain A. Khadayeir
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Zno Thin Films ◽  
Structural Behavior

scholarly journals Effects of Thermal Annealing on the Characteristics of High Frequency FBAR Devices

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 397
Author(s):  
Yu-Chen Chang ◽  
Ying-Chung Chen ◽  
Bing-Rui Li ◽  
Wei-Che Shih ◽  
Jyun-Min Lin ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Annealing ◽  
Electromechanical Coupling ◽  
Zno Thin Films ◽  
Electromechanical Coupling Coefficient ◽  
Back Side ◽  
Zno Thin Film ◽  
Frequency Responses ◽  
Sputtering System

In this study, piezoelectric zinc oxide (ZnO) thin film was deposited on the Pt/Ti/SiNx/Si substrate to construct the FBAR device. The Pt/Ti multilayers were deposited on SiNx/Si as the bottom electrode and the Al thin film was deposited on the ZnO piezoelectric layer as the top electrode by a DC sputtering system. The ZnO thin film was deposited onto the Pt thin film by a radio frequency (RF) magnetron sputtering system. The cavity on back side for acoustic reflection of the FBAR device was achieved by KOH solution and reactive ion etching (RIE) processes. The crystalline structures and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optimized as-deposited ZnO thin films with preferred (002)-orientation were obtained under the sputtering power of 80 W and sputtering pressure of 20 mTorr. The crystalline characteristics of ZnO thin films and the frequency responses of the FBAR devices can be improved by using the rapid thermal annealing (RTA) process. The optimized annealing temperature and annealing time are 400 °C and 10 min, respectively. Finally, the FBAR devices with structure of Al/ZnO/Pt/Ti/SiNx/Si were fabricated. The frequency responses showed that the return loss of the FBAR device with RTA annealing was improved from −24.07 to −34.66 dB, and the electromechanical coupling coefficient (kt2) was improved from 1.73% to 3.02% with the resonance frequency of around 3.4 GHz.

Plasma Pre-Treatment of Polyethylene Terephthalate Substrate Influence on the Properties of ZnO Thin Film

2014 ◽  
Vol 895 ◽  
pp. 41-44
Author(s):  
Seiw Yen Tho ◽  
Kamarulazizi Ibrahim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Polyethylene Terephthalate ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Water Contact ◽  
Pre Treatment ◽  
Pet Substrate

In this work, the influences of plasma pre-treatment on polyethylene terephthalate (PET) substrate to the properties of ZnO thin film have been carried out. ZnO thin films were successfully grown on PET substrate by spin coating method. In order to study the effects of plasma pre-treatment, a comparison of treated and untreated condition was employed. Water contact angle measurement had been carried out for PET wettability study prior to ZnO thin film coating. Morphology study of ZnO thin film was performed by scanning probe microscope (SPM). Besides, optical study of the ZnO thin film was done by using UV-vis spectrophotometer. All the measured results show that plasma pre-treatment of PET substrate plays an important role in enhancing the wettability of PET and optical properties of the ZnO thin films. In conclusion, pre-treatment of PET surface is essential to produce higher quality ZnO thin film on this particular substrate in which would pave the way for the integration of future devices.

scholarly journals Preparation of Glass Plate-Supported Nanostructure ZnO Thin Film Deposited by Sol-Gel Spin-Coating Technique and Its Photocatalytic Degradation to Monoazo Textile Dye

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammad Hossein Habibi ◽  
Mohammad Khaledi Sardashti
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Photocatalytic Degradation ◽  
Spin Coating ◽  
Sol Gel ◽  
Glass Plate ◽  
Zno Thin Films ◽  
Visible Range ◽  
Textile Dye ◽  
Axis Orientation

Glass plate-supported nanostructure ZnO thin films were deposited by sol-gel spin coating. Films were preheated at275∘Cfor 10 minutes and annealed at 350, 450, and550∘Cfor 80 minutes. The ZnO thin films were transparent ca 80–90% in visible range and revealed that absorption edges at about 370 nm. Thec-axis orientation improves and the grain size increases which was indicated by an increase in intensity of the (002) peak at34.4∘in XRD corresponding to the hexagonal ZnO crystal. The photocatalytic degradation of X6G an anionic monoazo dye, in aqueous solutions, was investigated and the effects of some operational parameters such as the number of layer and reusability of ZnO nanostructure thin film were examined. The results showed that the five-layer coated glass surfaces have a very high photocatalytic performance.

Exotic Doping for Zno Thin Films: Possibility of Monolithic Optical Integrated Circuit

1999 ◽  
Vol 574 ◽  
Author(s):  
Norifumi Fujimura ◽  
Tamaki Shimura ◽  
Toshifumi Wakano ◽  
Atsushi Ashida ◽  
Taichiro Ito
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Nonlinear Optic ◽  
Integrated Circuit ◽  
Film Surface ◽  
Zno Thin Films ◽  
Process Window ◽  
Electro Optic ◽  
Film Substrate ◽  
Optical Integrated Circuit

AbstractWe propose the application of ZnO:X (X = Li, Mg, N, In, Al, Mn, Gd, Yb etc.) films for a monolithic Optical Integrated Circuit (OIC). Since ZnO exhibits excellent piezoelectric effect and has also electro-optic and nonlinear optic effects and the thin films are easily obtained, it has been studied as one of the important thin film wave guide materials especially for an acoustooptic device[1]. In terms of electro-optic and nonlinear optic effects, however, LiNbO3 or LiTaO3 is superior to ZnO. The most important issue of thin film waveguide using such ferroelectrics is optical losses at the film/substrate interface and the film surface, because the process window to control the surface morphology is very narrow due to their high deposition temperature. Since ZnO can be grown at extremely low temperature, the roughness at the surface and the interface is expected to be minimized. This is the absolute requirement especially for waveguide using a blue or ultraviolet laser. Recently, lasing at the wavelength of ultraviolet, ferroelectric and antiferromagnetic behaviors of ZnO doped with various exotic elements (exotic doping) have been reported. This paper discusses the OIC application of ZnO thin films doped with exotic elements.

Sign in / Sign up

Export Citation Format

Share Document