scholarly journals Effects of Low Ag Doping on Physical and Optical Waveguide Properties of Highly Oriented Sol-Gel ZnO Thin Films

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Dehimi ◽  
Tahar Touam ◽  
Azeddine Chelouche ◽  
Fares Boudjouan ◽  
Djamel Djouadi ◽  
...  

A sol-gel dip-coating process was used to deposit almost stress-free highlyc-axis oriented zinc oxide (ZnO) thin films onto glass substrates. The effects of low silver doping concentration (Ag/Zn < 1%) on the structural, morphological, optical, and waveguide properties of such films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy, UV-Visible spectrophotometry, and M-lines spectroscopy (MLS). XRD analysis revealed that all the films were in single phase and had a hexagonal wurtzite structure. The grain size values were calculated and found to be about 24–29 nm. SEM micrographs and AFM images have shown that film morphology and surface roughness were influenced by Ag doping concentration. According to UV-Vis. measurements all the films were highly transparent with average visible transmission values ranging from 80% to 86%. It was found that the Ag contents lead to widening of the band gap. MLS measurements at 632.8 nm wavelength put into evidence that all thin film planar waveguides demonstrate a well-guided fundamental mode for both transverse electric and transverse magnetic polarized light. Moreover, the refractive index of ZnO thin films was found to increase by Ag doping levels.

2016 ◽  
Vol 675-676 ◽  
pp. 241-244 ◽  
Author(s):  
Tanattha Rattana ◽  
Sumetha Suwanboon ◽  
Chittra Kedkaew

Ni-doped ZnO thin films were prepared on glass slide substrates by a sol-gel dip coating method with different Ni doping concentrations (0-33 mol%). The effect of Ni doping concentration on structural, surface morphology and optical properties of the thin films was characterized by XRD, FESEM and UV-Vis spectrophotometer. The XRD results indicated that pure ZnO thin film exhibited a hexagonal wurtzite structure. Ni (OH)2 phase were observed at a high Ni doping concentration. The FESEM images showed that the surface morphology and surface roughness were sensitive to the Ni doping concentration. The optical transmission measurements were observed that the transmittance decreased with increasing the Ni doping concentration.


2020 ◽  
Vol 65 ◽  
pp. 27-38
Author(s):  
Sara Benzitouni ◽  
Mourad Zaabat ◽  
Jean Ebothé ◽  
Abdelhakim Mahdjoub ◽  
Meriem Guemini

Undoped and transition metals (TM = Cr, Ni, Mn and Cd) doped zinc oxide (ZnO) thin films were prepared by sol-gel dip-coating method on glass substrates at 300 °C. In this study, the effect of dopant material on the structural, morphological, optical, electrical and mechanical properties of ZnO thin films is investigated by using XRD, AFM, UV-Vis, Hall effect and nanoindentation techniques, respectively. Nanocrystalline films with a ZnO hexagonal wurtzite structure and two preferred orientations (002) and (103) were obtained. UV-Vis transmittance spectra showed that all the films are highly transparent in the visible region (> 80 %). Moreover, the optical band gap of the films decreased to 3.13 eV with an increasing orbital occupation number of 3d electrons. AFM-topography shows that the films are dense, smooth and uniform, except for the high roughness RMS =26.3 nm obtained for Cd-doped ZnO. Finally, the dopant material is found to have a significant effect on the mechanical behavior of ZnO as compared to the undoped material. For Ni and Cd dopants, analysis of load and unload data yields an increase in the hardness (8.96 ± 0.22 GPa) and Young’s modulus (122 ± 7.46 GPa) of ZnO as compared to Cr and Mn dopants. Therefore, Ni and Cd are the appropriate dopants for the design and application of ZnO-based nanoelectromechanical systems.


2014 ◽  
Vol 970 ◽  
pp. 120-123 ◽  
Author(s):  
Peh Ly Tat ◽  
Karim bin Deraman ◽  
Wan Nurulhuda Wan Shamsuri ◽  
Rosli Hussin ◽  
Zuhairi Ibrahim

Undoped nanocrystalline ZnO thin films were deposited onto the glass substrates via the low cost sol-gel dip coating method. The as-grown ZnO films were annealed at the temperatures ranging from 400 °C to 550 °C. The X-ray diffraction (XRD) pattern revealed that the annealed ZnO films were polycrystalline with hexagonal wurtzite structure and majority preferentially grow along (002) c-axis orientation. Atomic force microscopy (AFM) micrographs showed the improvement of RMS roughness and grain size as annealing temperature increased. The ZnO films that annealed at 500 oC exhibited the lowest resistivity value.


2017 ◽  
Vol 4 (9) ◽  
pp. 096403 ◽  
Author(s):  
Zohra N Kayani ◽  
Marya Siddiq ◽  
Saira Riaz ◽  
Shahzad Naseem

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3738 ◽  
Author(s):  
A. Smalenskaite ◽  
M. M. Kaba ◽  
I. Grigoraviciute-Puroniene ◽  
L. Mikoliunaite ◽  
A. Zarkov ◽  
...  

In this study, new synthetic approaches for the preparation of thin films of Mg-Al layered double hydroxides (LDHs) have been developed. The LDHs were fabricated by reconstruction of mixed-metal oxides (MMOs) in deionized water. The MMOs were obtained by calcination of the precursor gels. Thin films of sol–gel-derived Mg-Al LDHs were deposited on silicon and stainless-steel substrates using the dip-coating technique by a single dipping process, and the deposited film was dried before the new layer was added. Each layer in the preparation of the Mg-Al LDH multilayers was separately annealed at 70 °C or 300 °C in air. Fabricated Mg-Al LDH coatings were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and atomic force microscopy (AFM). It was discovered that the diffraction lines of Mg3Al LDH thin films are sharper and more intensive in the sample obtained on the silicon substrate, confirming a higher crystallinity of synthesized Mg3Al LDH. However, in both cases the single-phase crystalline Mg-Al LDHs have formed. To enhance the sol–gel processing, the viscosity of the precursor gel was increased by adding polyvinyl alcohol (PVA) solution. The LDH coatings could be used to protect different substrates from corrosion, as catalyst supports, and as drug-delivery systems in medicine.


2013 ◽  
Vol 667 ◽  
pp. 193-199 ◽  
Author(s):  
Mohd Firdaus Malek ◽  
Mohamad Hafiz Mamat ◽  
Mohamed Zahidi Musa ◽  
Mohd Zainizan Sahdan ◽  
Mohamad Rusop Mahmood

Recent research papers for zinc oxide (ZnO) thin films prepared by dip-coating method are reviewed. The aim is on the factors affecting the properties of ZnO thin films prepared by dip-coating method and the preparation of ZnO solution precursor using sol-gel process. Several of journals have been discovered to find out the related study on this topic. It was found that solution chemical equilibrium, substrate and thermal processing are the factors that contribute to the various properties of ZnO thin films. This review hopefully can help in improving the properties of ZnO thin film for possible applications to photoconductor, integrated sensor, transparent conducting oxide electrodes, optoelectronic devices and so on.


2014 ◽  
Vol 91 ◽  
pp. 13-18 ◽  
Author(s):  
A. Prichodko ◽  
V. Jonauske ◽  
M. Cepenko ◽  
A. Beganskiene ◽  
A. Kareiva

Calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp), tricalcium phosphate (Ca3(PO4)2, TCP) and calcium oxide (CaO) are the main components of inorganic part of human bones. Such synthetic nanocomposites could be very important implantable materials and using as substitute material for human hard tissues (bones and teeth). In this study, an aqueous sol-gel chemistry route has been developed to prepare nanostructured CHAp thin films on stainless steel substrate. For the preparation of thin films dip-coating and spin-coating techniques were used. The final samples were obtained by calcination of coatings for different time at 1000 °C. For the characterization of surface properties, the X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM) and the contact angle measurements were recorded.


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