scholarly journals Effect of Solvents and Stabilizer Molar Ratio on the Growth Orientation of Sol-Gel-Derived ZnO Thin Films

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
R. Bekkari ◽  
B. Jaber ◽  
H. Labrim ◽  
M. Ouafi ◽  
N. Zayyoun ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Molar Ratio ◽  
Bandgap Energy ◽  
Growth Orientation ◽  
Effect Of Solvents ◽  
Average Grain Size ◽  
Crystalline Growth

This work targets to control the growth orientation of sol-gel-derived ZnO thin films in order to allow different modes of excitation (longitudinal and transverse) when targeted to be used in piezoelectric applications. For that, the effect of solvents and stabilizer molar ratio on the structural and optical characteristics of the obtained films is investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectrophotometry. The XRD results show clearly that the synthesized films exhibit hexagonal wurtzite structure without any secondary phases and that the crystallite average size, estimated by the Scherrer formula, is ranged between 13 and 30 nm. The main finding of this work is to show that the control of the crystalline growth orientation is possible simply by varying the solvent nature and/or the stabilizer molar ratio. These later parameters are therefore considered as key factors when seeking to develop the ZnO-based transducers. Actually, the ZnO thin films synthesized with propanol as solvent are oriented only along the c-axis; meanwhile, when using the isopropanol or ethanol, other preferential orientations appear. Additionally, the effect of MEA molar ratio (r) has been studied on the propanol-derived films (the unfavorable case). It has been found that this parameter has a direct effect on the crystalline growth orientation of these films and that a new preferential orientation (100) appears at low r. On the other hand, SEM images show the formation of homogeneous nanocrystalline thin films with an average grain size ranged between 19 and 35 nm. Moreover, the ZnO thin films exhibit a high transparency in the visible region, and the measured transmittance is ranged from 85 to 97%. However, the change of ZnO film orientation has no significant effect on the direct bandgap energy which is closed to 3.30 eV.

Photocatalytic Properties of ZnO and Ag Doped ZnO Thin Films

2014 ◽  
Vol 685 ◽  
pp. 3-6
Author(s):  
Ying Lian Wang ◽  
Jun Yao Ye
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Structural Features ◽  
Photocatalytic Properties ◽  
Zno Thin Films ◽  
Molar Ratio ◽  
Zno Films ◽  
Doped Zno ◽  
Excellent Adhesion

Pure ZnO thin films and Ag doped ZnO thin films were prepared on quartz substrates by sol-gel process. Structural features and UV absorption spectrum have been studied by XRD and UV-Vis-Nir scanning spectrophotometer. Taking phenol as pollutants, further study of the effect of different annealing temperature and Ag dopant amount of ZnO films on photocatalytic properties was carried out. The results showed that, the optimal annealing temperature on photocatalytic degradation of phenol in this experiment was 300 °C, the best molar ratio of ZnO and Ag was 30:1, which was better than pure ZnO film greatly. Excellent adhesion, recyclable and efficient degradation Ag doped ZnO thin films were found in this experiment.

Structural and Optical Studies of Molarity Based ZnO Thin Films

2017 ◽  
Vol 17 ◽  
pp. 140-148 ◽  
Author(s):  
A. Jacquiline Regina Mary ◽  
S. Arumugam
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Visible Region ◽  
Precursor Solution ◽  
Hexagonal Wurtzite Structure ◽  
Solution Concentration ◽  
Molar Concentration ◽  
Zno Thin Films ◽  
Zno Films ◽  
Average Grain Size

Zinc Oxide thin films were prepared for different precursor solution molarities from 0.025M to 0.1M by spray pyrolysis deposition technique. A comprehensive study was carried out to realize the effect of concentration of precursor on ZnO thin films. The optimized temperature of the glass substrate was 300°C. From the XRD data it is inferred that the films are polycrystalline and hexagonal wurtzite structure . The degree of preferred orientation were along diffraction planes (100), (002) and (101) for all the ZnO films. The intensity of the diffraction peak prepared with 0.1M concentration is higher than those prepared at lower concentrations. The grain size (D) was calculated using Debye-Scherrer formula. It was found that the average grain size increases, when the molar concentration increases. As the solution concentration increases, the band gap decreases. The films are transparent in the visible region (85%), and the transmittance decreases as the molar concentration increases, which is caused by optical scattering at grain boundaries.

scholarly journals Growth of Zn1−x CdxO nanocrystalline thin films by sol-gel method and their characterization for optoelectronic applications

2014 ◽  
Vol 32 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Munirah Munirah ◽  
Ziaul Khan ◽  
Mohd. Khan ◽  
Anver Aziz
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Band Edge Emission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cd Doping ◽  
Vis Spectroscopy ◽  
Doped Zno

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.

INFLUENCE OF POST ANNEALING ON SOL–GEL DEPOSITED ZnO THIN FILMS

2014 ◽  
Vol 21 (04) ◽  
pp. 1450046 ◽  
Author(s):  
HEMALATA BHADANE ◽  
EDMUND SAMUEL ◽  
DINESH KUMAR GAUTAM
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Visible Region ◽  
Average Crystallite Size ◽  
Zno Thin Films ◽  
Nanocrystalline Films ◽  
Post Annealing ◽  
Deposited Films ◽  
Lower Resistivity

The effect of annealing temperature on sol–gel deposited ZnO thin films have been studied. The average crystallite size determined from XRD shows that the deposited films are nanocrystalline. FTIR confirms deposition of ZnO thin films. The transmittance of annealed ZnO thin films is greater than 80% in visible region with bandgap ranging from 3.25–3.19 eV. The films annealed at 450°C temperature shows lower resistivity value of 527.241 Ωm. The deposited nanocrystalline films are suitable for biosensing applications due to its higher surface area.

EFFECTS OF Ge DOPING THROUGH ION IMPLANTATION ON THE STRUCTURAL AND OPTICAL PROPERTIES OF ZnO THIN FILMS PREPARED BY SOL-GEL TECHNIQUE

2007 ◽  
Vol 21 (31) ◽  
pp. 5257-5263 ◽  
Author(s):  
S. W. XUE ◽  
X. T. ZU ◽  
X. XIANG ◽  
M. Y. CHEN ◽  
W. G. ZHENG
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Ion Implantation ◽  
Deep Level ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Zno Films ◽  
Near Band Edge ◽  
Structural And Optical Properties

ZnO thin films were first prepared by the sol–gel process, and then Ge ions were implanted into the ZnO films. The effects of ion implantation on the structural and optical properties of the ZnO films were investigated by X-ray diffraction, photoluminescence (PL), and optical transmittance measurements. Measurement results showed that the intensity of the (002) diffraction peak was decreased and the full width at half maximum was narrowed. PL emission was greatly extinguished after Ge ion implantation. Both the near band edge (NBE) excitonic UV emission at 391 nm and the defect related deep level emission centered at 470 nm in the visible region were decreased after Ge ion implantation. NBE peak and the absorption edge were observed to have a blueshift toward higher energy.

scholarly journals Al-doped and pure ZnO thin films elaborated by sol-gel spin coating process for optoelectronic applications

2017 ◽  
Vol 51 (12) ◽  
pp. 1663 ◽  
Author(s):  
M. Maache ◽  
T. Devers ◽  
A. Chala
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Sol Gel ◽  
Visible Region ◽  
Band Gap Energy ◽  
Molar Ratio ◽  
Wurtzite Phase ◽  
Homogeneous Surface ◽  
Aluminum Doped Zinc Oxide ◽  
Dopant Source

Pure and aluminum-doped zinc oxide thin films were grown by spin coating at room temperature. As a starting material, zinc acetate was used. The dopant source was aluminum nitrate; the dopant molar ratio was varied between 1 and 10%. Structural analysis reveals that all films consist of single hexagonal wurtzite phase ZnO, and a preferential orientation along c-axis. They have a homogeneous surface. The measurements show that the films are nanostructured. The transmittance is greater than 75% in the visible region. The band gap energy decreases with the addition of dopant (Al) in prepared thin films and the resistivity decreases significantly. DOI: 10.21883/FTP.2017.12.45182.8078

scholarly journals Structural, Chemical and Optical Properties of Pure and Al-Doped Zno Thin Films Derived by Sol–Gel Dip Coating Process

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali sadek Kadari ◽  
Abdelkader Nebatti Ech-Chergui ◽  
Mohamed walid Mohamedi ◽  
Abdelhalim Zoukel ◽  
Tair Sabrina ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Sol Gel ◽  
Visible Region ◽  
Dip Coating ◽  
Band Gap Energy ◽  
Sem Analysis ◽  
Zno Thin Films ◽  
X Ray ◽  
Doped Zno

Abstract Pure and Al-doped ZnO thin films were successfully deposited with sol-gel dip coating on both substrates Si (100) and glass. The structural, chemical, morphological and optical properties as a function of the annealing temperature and dopant atomic concentration were investigated by means of X-ray diffraction, Energy dispersive X-ray, Scanning Electron Microscopy, and spectrophotometry. All the pure and doped films show a polycrystalline nature and hexagonal in structure. Accurate doping was proven by EDX. In addition, the SEM analysis revealed that the films possess uniform distribution throughout the surface and the grain dimension decreases with Al doping. From the transmittance measurements, it is see that all films are over 55% in the visible region and the band gap energy increases from 3.28 to 3.45 eV with the increase of Al concentration.

Effect of Transition Metals on the Mechanical Properties of ZnO Thin Films, Prepared by Sol-Gel Method

2020 ◽  
Vol 65 ◽  
pp. 27-38
Author(s):  
Sara Benzitouni ◽  
Mourad Zaabat ◽  
Jean Ebothé ◽  
Abdelhakim Mahdjoub ◽  
Meriem Guemini
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Transition Metals ◽  
Occupation Number ◽  
Sol Gel ◽  
Visible Region ◽  
Hexagonal Wurtzite Structure ◽  
Dip Coating ◽  
Zno Thin Films ◽  
Nanoelectromechanical Systems

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.

Synthesis, Characterization and Hall Effect Measurements of Nanocrystalline ZnO Thin Films

2012 ◽  
Vol 510-511 ◽  
pp. 186-193 ◽  
Author(s):  
Ashari Maqsood ◽  
M. Islam ◽  
M. Ikram ◽  
S. Salam ◽  
S. Ameer
Keyword(s):  
Thin Films ◽  
Hall Effect ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Zno Films ◽  
Morphological Studies ◽  
Hall Effect Measurements ◽  
Scherrer Formula

ZnO thin films were prepared by sol-gel method. Prepared thin films were then characterized by SEM, XRD, EDX and Hall effect measurements. SEM confirmed the morphological studies of ZnO thin films. Crystallite size is calculated using the Scherrer formula. Crystallite and grain sizes are obtained through XRD and SEM. EDS analysis confirms mass percentage of ZnO deposited. Decreasing trend of magneto resistance with temperature is observed. The optical transmission spectra of the solgel deposited ZnO thin films showed high transmittance (>70%) in the visible region and indicates that the transmittance of ZnO films gradually decreased as the thickness increased. Decreasing trend of resistivity and sheet resistance with thickness are also observed. The IV characterization of ZnO thin films under influence of UV and dark conditions are reported. The dc electrical resistivity data follow the hoping model.

Regulations of aging time on optical properties of nano-crystalline ZnO thin films fabricated by sol–gel method

2017 ◽  
Vol 10 (03) ◽  
pp. 1750024
Author(s):  
Jitao Li ◽  
Dingyu Yang ◽  
Xinghua Zhu ◽  
Hui Sun ◽  
Xiuying Gao ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Aging Time ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Visible Range ◽  
Gel Method ◽  
Sol Gel Method ◽  
Nano Crystalline

Nano-crystalline Zinc oxide (ZnO) thin films on glass substrates have been fabricated by sol–gel method for different aging times. The thermal curve of the dried gel was examined and it was found that evaporation of solvent and the decomposition of the organics have completed before 250[Formula: see text]C. X-ray diffraction patterns and Atomic Force Microscope images of samples only have a small difference of microstructure. The transmittance spectra revealed high transmittance in visible region. The optical band gap of the samples remined stable (3.28[Formula: see text]eV). Also, the Urbach energy was calculated to explain the defect concentration. The Photoluminescence spectra in ultraviolet and visible regions were studied, and the decreased intensity of peaks at 387[Formula: see text]nm and the increased emissions in visible range were found. The results showed that excessive aging time can cause degeneration of optical properties of thin films.

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