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 Effect of Solution Conditions on the Properties of Sol–Gel Derived Potassium Sodium Niobate Thin Films on Platinized Sapphire Substrates

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1600 ◽  
Author(s):  
Alexander Tkach ◽  
André Santos ◽  
Sebastian Zlotnik ◽  
Ricardo Serrazina ◽  
Olena Okhay ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Low Cost ◽  
Sol Gel ◽  
Precursor Solution ◽  
Dissipation Factor ◽  
Solution Concentration ◽  
Potassium Sodium Niobate ◽  
Sapphire Substrates ◽  
Average Grain Size

If piezoelectric micro-devices based on K0.5Na0.5NbO3 (KNN) thin films are to achieve commercialization, it is critical to optimize the films’ performance using low-cost scalable processing conditions. Here, sol–gel derived KNN thin films are deposited using 0.2 and 0.4 M precursor solutions with 5% solely potassium excess and 20% alkali (both potassium and sodium) excess on platinized sapphire substrates with reduced thermal expansion mismatch in relation to KNN. Being then rapid thermal annealed at 750 °C for 5 min, the films revealed an identical thickness of ~340 nm but different properties. An average grain size of ~100 nm and nearly stoichiometric KNN films are obtained when using 5% potassium excess solution, while 20% alkali excess solutions give the grain size of 500–600 nm and (Na + K)/Nb ratio of 1.07–1.08 in the prepared films. Moreover, the 5% potassium excess solution films have a perovskite structure without clear preferential orientation, whereas a (100) texture appears for 20% alkali excess solutions, being particularly strong for the 0.4 M solution concentration. As a result of the grain size and (100) texturing competition, the highest room-temperature dielectric permittivity and lowest dissipation factor measured in the parallel-plate-capacitor geometry were obtained for KNN films using 0.2 M precursor solutions with 20% alkali excess. These films were also shown to possess more quadratic-like and less coercive local piezoelectric loops, compared to those from 5% potassium excess solution. Furthermore, KNN films with large (100)-textured grains prepared from 0.4 M precursor solution with 20% alkali excess were found to possess superior local piezoresponse attributed to multiscale domain microstructures.

Influence of Precursor Solution Concentration on Structure and Magnetic Properties of Zinc Oxide Thin Films

2016 ◽  
Vol 724 ◽  
pp. 43-47
Author(s):  
H.S. Sindhu ◽  
Sumanth Joishy ◽  
B.V. Rajendra ◽  
P.D. Babu
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Magnetic Properties ◽  
Precursor Solution ◽  
Hexagonal Wurtzite Structure ◽  
Solution Concentration ◽  
Zno Films ◽  
Spray Pyrolysis Method ◽  
Oxide Thin Films ◽  
Deposited Films

Zinc oxide thin films were deposited on glass substrate at a substrate temperature of 673K by spray pyrolysis method using different concentration of 0.0125M, 0.025M and 0.05M of Zinc acetate solutions. The effect of molar concentrations on structure, surface morphology and magnetic properties of ZnO films were investigated using x-ray diffraction, scanning electron microscopy and vibrating sample magnetometer. All deposited films were polycrystalline in nature with hexagonal wurtzite structure having a preferential growth orientation along (101) plane. An improvement of crystallinity in the deposits with increasing concentration of sprayed solution was noticed. All deposit exhibit fibrous structure which increases with increase of precursor concentration solutions. At room temperature, all deposited films were shown diamagnetic character but when cooled to 5K, they have shown paramagnetic characteristics.

scholarly journals Structural, Optoelectrical, Linear, and Nonlinear Optical Characterizations of Dip-Synthesized Undoped ZnO and Group III Elements (B, Al, Ga, and In)-Doped ZnO Thin Films

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 252 ◽  
Author(s):  
A. M. Alsaad ◽  
A. A. Ahmad ◽  
I. A. Qattan ◽  
Qais M. Al-Bataineh ◽  
Zaid Albataineh
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Optical Properties ◽  
Nonlinear Optical ◽  
Zno Thin Films ◽  
Zno Films ◽  
Optical Parameters ◽  
Group Iii ◽  
Doped Zno

Undoped ZnO and group III (B, Al, Ga, and In)-doped ZnO thin films at 3% doping concentration level are dip-coated on glass substrates using a sol-gel technique. The optical properties of the as-prepared thin films are investigated using UV–Vis spectrophotometer measurements. Transmittance of all investigated thin films is found to attain high values of ≥80% in the visible region. We found that the index of refraction of undoped ZnO films exhibits values ranging between 1.6 and 2.2 and approximately match that of bulk ZnO. Furthermore, we measure and interpret nonlinear optical parameters and the electrical and optical conductivities of the investigated thin films to obtain a deeper insight from fundamental and practical points of view. In addition, the structural properties of all studied thin film samples are investigated using the XRD technique. In particular, undoped ZnO thin film is found to exhibit a hexagonal structure. Due to the large difference in size of boron and indium compared with that of zinc, doping ZnO thin films with these two elements is expected to cause a phase transition. However, Al-doped ZnO and Ga-doped ZnO thin films preserve the hexagonal phase. Moreover, as boron and indium are introduced in ZnO thin films, the grain size increases. On the other hand, grain size is found to decrease upon doping ZnO with aluminum and gallium. The drastic enhancement of optical properties of annealed dip-synthesized undoped ZnO thin films upon doping with group III metals paves the way to tune these properties in a skillful manner, in order to be used as key candidate materials in the fabrication of modern optoelectronic devices.

scholarly journals Influence of Annealing on Properties of Spray Deposited ZnO Thin Films

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Kalyani Nadarajah ◽  
Ching Yern Chee ◽  
Chou Yong Tan
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Spray Pyrolysis Technique ◽  
Hexagonal Wurtzite Structure ◽  
Ambient Air ◽  
Zno Thin Films ◽  
Visible Range ◽  
X Ray ◽  
Average Grain Size ◽  
Vis Spectroscopy

Zinc Oxide (ZnO) thin films were deposited on glass substrates via the spray pyrolysis technique. The films were subsequently annealed in ambient air from 300°C to 500°C. The morphology and structural properties of the thin films were studied by field emission scanning electron microscope (FESEM), atomic force microscopy (AFM), and X-ray diffractometry (XRD) techniques. Electrical resistivity of the thin films was measured using a data acquisition unit. The optical properties of the films were characterized by UV-vis spectroscopy and photoluminescence (PL) technique. X-ray diffraction data showed that the films were grown in the (002) direction with a hexagonal wurtzite structure. The average grain size ranged from 15 to 27 nm. Increasing annealing temperatures resulted in larger grain sizes and higher crystallinity, with the surface roughness of annealed films being more than twice if compared to unannealed film. The electrical resistivity of the films decreased with the increasing annealing temperature. The UV and visible band emissions were observed in the photoluminescence spectra, due to exciton and defect-related emissions, respectively. The transmission values of the films were as high as 90% within the visible range (400–700 nm).

SYNTHESIS AND CHARACTERIZATION OF Fe–ZnO THIN FILMS FOR ANTIMICROBIAL ACTIVITY

2019 ◽  
Vol 26 (05) ◽  
pp. 1850197 ◽  
Author(s):  
SELMA M. H. AL-JAWAD ◽  
SABAH H. SABEEH ◽  
ALI A. TAHA ◽  
HUSSEIN A. JASSIM
Keyword(s):  
Thin Films ◽  
Doping Concentration ◽  
Optical Bandgap ◽  
Zno Thin Films ◽  
Zno Films ◽  
Fe Doping ◽  
E Coli ◽  
Average Grain Size ◽  
Vis Spectroscopy ◽  
Doped Zno

Pure and Fe-doped zinc oxide (ZnO) sol–gel thin films were deposited by spin-coating process. Pure ZnO and Fe–ZnO films, containing Fe of 2–8[Formula: see text]wt.%, were annealed at 500∘C for 2[Formula: see text]h. All prepared thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV–visible (UV–vis) spectroscopy. XRD studies show the polycrystalline nature with hexagonal wurtzite structure of pure ZnO and Fe–ZnO thin films. The crystallite size of the prepared samples reduced with increasing Fe doping concentrations. AFM and SEM results indicated that the average grain size decreased as Fe doping concentration increased. The transmittance spectra were then recorded at wavelengths ranging from 300[Formula: see text]nm to 1000[Formula: see text]nm. The films produced yielded high transmission at visible regions. The optical bandgap energy of spin-coated films also decreased as Fe doping concentration increased. In particular, their optical bandgap energies were 3.75, 3.6, 3.5, 3.45 and 3.3 eV at 0-, 2-, 4-, 6- and 8-wt.% Fe concentrations, respectively. Antibacterial activities of pure ZnO and Fe–ZnO against E. coli and S. aureus were evaluated by international recognized test (JIS Z 2801). The results showed that pure and Fe-doped ZnO thin films have antibacterial inhibition zone against E. coli and S. aureus. Gram-positive bacteria seemed be more resistant to pure and Fe-doped ZnO thin films than gram-negative bacteria. The test shows an incremental increase in antibacterial activity of the thin films when dopant ratio increased under UV light.

Properties of Al Doped ZnO Thin films by DC Reaction Magnetron Sputtering

2011 ◽  
Vol 306-307 ◽  
pp. 362-367
Author(s):  
Feng Lu ◽  
Yu Sun ◽  
Cheng Hai Xu
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Visible Region ◽  
Hexagonal Wurtzite Structure ◽  
Zno Thin Films ◽  
High Quality ◽  
Electrical And Optical Properties ◽  
Polycrystalline Hexagonal Wurtzite Structure ◽  
Doped Zno

The high quality ZAO thin films were successfully produced by DC reaction magnetron sputtering technology. The XRD，electrical and optical properties of films are particular investigated. The results show that ZAO films are polycrystalline hexagonal wurtzite structure，and Al2O3 crystal phase are not found. At the same time，the high quality ZAO films with the minimum resistivity of 4.5x10-4Ω•㎝, the transmittance in visible region above 80% and the reflectivity in IR region above 70% are gained.

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 Effect of molar concentration on the optical and structural properties of ZnO thin films prepared by chemical bath deposition method

2020 ◽  
Vol 12 (01) ◽  
pp. 66-72
Author(s):  
Qasim Chfat Abdulridha ◽  
◽  
Hussein Ali Noor ◽  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Energy Gap ◽  
Hexagonal Structure ◽  
Molar Concentration ◽  
Zno Thin Films ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Heterogeneous Distribution ◽  
Preferred Direction

This research included the preparation of (ZnO) thin films by CBD technique for the deposition of chemical bath thickness (150 ± 20nm). X-ray diffraction was analyzed and showed that the films crystallize in a polycrystalline hexagonal structure, with a preferred direction along the level (100). Increased volume of calculated crystals for deposited films was found by increasing molar concentration. The surface morphology of films was studied by SEM, and the surface morphology of ZnO films is a heterogeneous distribution. The optical properties of all deposited ZnO films contained a spectral permeability and absorption spectrum in the wavelength range (300-1100nm), and the transmittance decreased with increasing molar concentration, it was found that the value of the light energy gap (Eg) increases with increasing molecular concentration band gap between 3.1 and 3.2 eV.

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.

The Structural Characterization and Optical Properties of Zinc Oxide Films Synthesized by Electrochemistry Method

2013 ◽  
Vol 743-744 ◽  
pp. 926-931
Author(s):  
Jing Xia Zheng ◽  
Xing Guo Zhao ◽  
Wei Liang ◽  
Jin Bo Xue
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Electrolyte Concentration ◽  
Hexagonal Wurtzite Structure ◽  
Zinc Nitrate ◽  
Zno Thin Films ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Ito Glass ◽  
The Matrix

Flaky ZnO thin films were electrodeposited from an aqueous solution of zinc nitrate (Zn (NO3)2) as electrolyte on ITO glass substrate by cathodic reduction method The effect of electrolyte concentration on the structure, morphology and optical properties of ZnO thin films were studied by X-ray diffraction, scanning electron microscopy and UV-Vis spectrometer. The results show that the ZnO films are of hexagonal wurtzite structure; When the concentration of Zn (NO3)2 solution is 0.24 M, the sparse flaky ZnO thin films were prepared and the thickness and length of ZnO flaky are about 50 nm and 1~3 μm, respectively; When the electrolyte concentration is 0.16 M, hexagonal and triangular structures are observed and some lathy and conical ZnO structure start to appear; When the concentration of Zn (NO3)2 solution drops to 0.08 M, the matrix of films is still flaky ZnO, but porous structures among the flaky structures appear and the size of conical ZnO has changed, whose bottom diameter reaches 1~3 μm and length is 2~4 μm; UV-Vis absorption test results indicate the absorption peak and the bandgap of the prepared ZnO thin films are about 350 nm and 3.28 eV, respectively.

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