scholarly journals Sensing of Ethanol with Nanosize Fe-ZnO Thin Films

2009 ◽  
Vol 2009 ◽  
pp. 1-3 ◽  
Author(s):  
G.-H. Kuo ◽  
H. Paul Wang ◽  
H. H. Hsu ◽  
James Wang ◽  
Y. M. Chiu ◽  
...  

Sensing of ethanol with iron doped ZnO (Fe-ZnO) thin films has been studied in this work. By X-ray diffraction spectroscopy, it is found that ZnO is the main compound in the low-iron (<10%) doped ZnO thin films.ZnFe2O4is also found as 20–50% of iron are doped on the thin films. The 5% Fe-ZnO thin film has a very high sensitivity (Rair/Rethanol>70) to 1000 ppm of ethanol at 300 K. It seems that iron can promote the sensivity of the ZnO thin film. The thin film doped with a greater amount (20–50%) of iron has, however, a much less sensitivity (<15) to ethanol. The chemical interactions between oxygen of ethanol and zinc on the Fe-ZnO thin film cause changes of the bond distances of Zn–O and Fe–O in the thin films to 1.90 and 1.98 Å which can be restored to 1.91 and 1.97 Å, respectively, in the absence of ethanol.

2008 ◽  
Vol 47-50 ◽  
pp. 1117-1120
Author(s):  
G.H. Kuo ◽  
H. Paul Wang ◽  
H.H. Hsu ◽  
Chih Ju G. Jou ◽  
Y.M. Chiu ◽  
...  

In the present work, sensing of ethanol on the ZnO thin films doped with Fe (5-50%) have been investigated. Nature of the sensing species in the nanosize Fe-doped ZnO (FeZnO) thin films has also been studied by in situ extended X-ray absorption fine structure (EXAFS) spectroscopy. By XRD, it is found that ZnO and ZnFe2O4 are the main compounds in the ZnO-Fe thin films. The thin film containing 5% of Fe has a high sensitivity (Rair/Rethanol>80) when sensing of ethanol at 300 K. On the contrary, the thin films with Fe fractions of 20-50% have a very low sensitivity to ethanol (Rair/Rethanol<15). In the presence of ethanol, the EXAFS spectra show that the bond distances of Zn-O and Fe-O in the thin films are 1.90 and 1.98 Å, respectively and restored to 1.91 and 1.97 Å in the absence of ethanol.


2013 ◽  
Vol 795 ◽  
pp. 403-406 ◽  
Author(s):  
Nur Sa’adah Muhamad Sauki ◽  
Sukreen Hana Herman ◽  
Mohd Hanafi Ani ◽  
Mohamad Rusop

Zinc oxide (ZnO) thin films were deposited on teflon substrates by RF magnetron sputtering at different substrate temperature. The effect of substrate temperature on ZnO thin films electrical and structural properties were examined using current-voltage (I-V) measurement, and x-ray diffraction (XRD) It was found that the electrical conductivity and resistivity of the ZnO thin film deposited at 40°C was the highest and lowest intensity accordingly. This was supported by the crystalline quality of the films from the x-ray diffraction (XRD) results. The XRD pattern showed that the ZnO thin film deposited at 40°C has the highest intensity with the narrowest full-width-at-half-maximum indicating that the film has the highest quality compared to other thin film.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Deepu Thomas ◽  
Sunil C. Vattappalam ◽  
Sunny Mathew ◽  
Simon Augustine

ZnO thin films were prepared by successive ionic layer adsorption reaction (SILAR) method. The textured grain growth along c-axis in pure ZnO thin films and doped with Sn was studied. The structural analysis of the thin films was done by X-ray diffraction and surface morphology by scanning electron microscopy. Textured grain growth of the samples was measured by comparing the peak intensities. Textured grain growth and photo current in ZnO thin films were found to be enhanced by doping with Sn. ZnO thin film having good crystallinity with preferential (002) orientation is a semiconductor with photonic properties of potential benefit to biophotonics. From energy dispersive X-ray analysis, it is inferred that oxygen vacancy creation is responsible for the enhanced textured grain growth in ZnO thin films.


2005 ◽  
Vol 879 ◽  
Author(s):  
M. Abid ◽  
C. Terrier ◽  
J-P Ansermet ◽  
K. Hjort

AbstractFollowing the theory, ferromagnetism is predicted in Mn- doped ZnO, Indeed, ferromagnetism above room temperature was recently reported in thin films as well as in bulk samples made of this material. Here, we have prepared Mn doped ZnO by electrodeposition. The samples have been characterized by X-ray diffraction and spectroscopic methods to ensure that the dopants are substitutional. Some samples exhibit weak ferromagnetic properties at room temperature, however to be useful for spintronics this material need additional carriers provided by others means.


2014 ◽  
Vol 32 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Munirah Munirah ◽  
Ziaul Khan ◽  
Mohd. Khan ◽  
Anver Aziz

AbstractThis paper describes the growth of Cd doped ZnO thin films on a glass substrate via sol-gel spin coating technique. The effect of Cd doping on ZnO thin films was investigated using X-ray diffraction (XRD), UV-Vis spectroscopy, photoluminescence spectroscopy, I–V characteristics and field emission scanning electron microscopy (FESEM). X-ray diffraction patterns showed that the films have preferred orientation along (002) plane with hexagonal wurtzite structure. The average crystallite sizes decreased from 24 nm to 9 nm, upon increasing of Cd doping. The films transmittance was found to be very high (92 to 95 %) in the visible region of solar spectrum. The optical band gap of ZnO and Cd doped ZnO thin films was calculated using the transmittance spectra and was found to be in the range of 3.30 to 2.77 eV. On increasing Cd concentration in ZnO binary system, the absorption edge of the films showed the red shifting. Photoluminescence spectra of the films showed the characteristic band edge emission centred over 377 to 448 nm. Electrical characterization revealed that the films had semiconducting and light sensitive behaviour.


2021 ◽  
Vol 43 (3) ◽  
pp. 253-253
Author(s):  
Mehmet zkan Mehmet zkan ◽  
Sercen Sadik Erdem Sercen Sadik Erdem

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.


2012 ◽  
Vol 485 ◽  
pp. 144-148
Author(s):  
Jian Lin Chen ◽  
Yan Jie Ren ◽  
Jian Chen ◽  
Jian Jun He ◽  
Ding Chen

Preferentially oriented Al-doped ZnO thin films with doping concentration of 1, 2, 3, 5 and 10 mol% respectively were prepared on glass substrates via sol-gel route. The crystallinity of films was characterized by X-ray diffraction and the surface morphologies were observed by scanning electron microscopy. The results show that ZnO:Al films at low doping concentration (1, 2 mol%) grow into dense homogenous microstructure. However, as for high doping concentration (3, 5, 10 mol%), Al3+ precipitate in the form of amorphous Al2O3 and ZnO:Al films exhibit heterogeneous nucleation and exceptional growth of the big plate-like crystals at the interface of the amorphous Al2O3 and ZnO:Al matrix.


2017 ◽  
Vol 05 (01) ◽  
pp. 1750004
Author(s):  
R. Vettumperumal ◽  
S. Kalyanaraman ◽  
R. Thangavel

Nanocrystalline ruthenium (Ru)-doped ZnO thin films on sapphire substrate was prepared using sol–gel method by spin coating technique. The structural and I-V characteristics of Ru doped ZnO thin films were studied from the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) analysis and Raman spectroscopy. X-ray diffraction (XRD) results revealed that the deposited films belonged to hexagonal wurtzite structure with c-axis orientation. It is also confirmed from the Raman spectra. Enhancement of longitudinal optical (LO) phonon is observed by the strong electron–phonon interaction. An observed increment in sheet resistance with increase in dopant percentage of Ru (1–2[Formula: see text]mol%) in ZnO films was found and better I-V characteristic behavior was observed at 1[Formula: see text]mol% of Ru-doped ZnO thin films. Trap limited current flow inside the material was calculated from the log I versus log V plot in the higher voltage region.


Author(s):  
Tran Thi Ngoc Anh ◽  
Tran Thi Ha ◽  
Nguyen Viet Tuyen ◽  
Pham Nguyen Hai

This paper presents results of preparation of Ag doped ZnO bulk sample by solid state reaction and Ag doped ZnO thin films by sputtering method. Effect of doping concentration (1, 2 and 4%) on the properties of the thin films was investigated. Various methods were utilized to investigate characteristics of the samples: X-ray diffraction, Raman scattering spectroscopy, photoluminescence, energy dispersive X-Ray spectroscopy, scanning electron microscopy, atomic force microscope, absorption spectroscopy and Hall measurement. The results show that Ag diffused into ZnO crystal lattice after heat treatment at 1200oC. As-prepared thin film samples exhibit low resistivity in the order of 10-3Ω.cm. The film doped with 2% Ag shows the lowest resistivity of 1.8´10-3Ω.cm which is potential for making transparent electrodes in optoelectronics.


2007 ◽  
Vol 124-126 ◽  
pp. 339-342
Author(s):  
Gun Hee Kim ◽  
Hong Seong Kang ◽  
Dong Lim Kim ◽  
Hyun Woo Chang ◽  
Byung Du Ahn ◽  
...  

Cu-doped ZnO (denoted by ZnO:Cu) films have been prepared by pulsed laser deposition using 3 wt. CuO doped ZnO ceramic target. The carrier concentrations (1011~1018 cm-3) and, electrical resistivity (10-1~105 cm) of deposited Cu-doped ZnO thin films were varied depending on deposition conditions. Variations of electrical properties of Cu-doped ZnO indicate that copper dopants may play an important role in determining their electrical properties, compared with undoped films. To investigate effects of copper dopants on the properties of ZnO thin films, X-Ray diffraction (XRD), photoluminescence (PL), and Hall measurements have been performed and corresponded.


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