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).

scholarly journals The study of transparent conducting gallium doped ZnO thin films in order to use in solar cells

2018 ◽  
Vol 6 (2) ◽  
pp. 56
Author(s):  
Mojtaba Mahmoudzadeh Pirvahshi
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis Technique ◽  
Hexagonal Wurtzite Structure ◽  
Growth Direction ◽  
Zno Thin Films ◽  
Visible Range ◽  
Chemical Spray Pyrolysis ◽  
Range Data ◽  
Transparent Conducting ◽  
Doped Zno

In this study, transparent conducting Ga-doped ZnO thin films were deposited on glass substrate using chemical spray pyrolysis technique. The effect of Ga-doping concentration (0, 1, 2 and 3 at.%) on microstructural, optical and electrical characteristics of layers have been investigated. The studies of X-ray diffraction and optical transmission spectra show these films have a hexagonal wurtzite structure with (002) preferred growth direction, also a high transmission of 85-95% in visible range. Data analysis show that the band gap energies in these films are varying in the range of 3.27-3.33 eV, consistent with the Burstein-Moss shift effect, with Urbach tail widths between 114-160 meV. The 2 wt% Ga sample showed the maximum figure of merit (3×10-2Ω-1), with an electron concentration and sheet resistance of ~1.42×1019 cm-3 and 13 kΩ/square, respectively.  

Effects of Mn doping on electrical properties of ZnO thin films

2016 ◽  
Vol 30 (04) ◽  
pp. 1650024 ◽  
Author(s):  
Leili Motevalizadeh ◽  
Boshra Ghanbari Shohany ◽  
Majid Ebrahimizadeh Abrishami
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Spray Pyrolysis Technique ◽  
Oxygen Deficiency ◽  
Zno Thin Films ◽  
Zno Films ◽  
Mn Doping ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Mn Doped

In this paper, we have investigated the effect of Mn doping on the electrical properties of ZnO thin films. ZnO thin films with different amounts of Mn concentrations (0, 5, 10 and 15 mol.%) were prepared by spray pyrolysis technique. The crystal structure was examined by X-ray diffraction (XRD) analysis. XRD patterns showed that all the samples were crystallized in wurtzite structure while a decrease in crystallinity and switch in preferential orientations were observed in Mn-doped thin films comparing to undoped ZnO. The element composition of all thin films was detected by energy dispersive X-ray (EDX). The surface morphology of the films was investigated using field emission scanning electron microscope (FESEM) and optical properties were studied using UV-vis spectroscopy. UV-vis study revealed that the band gap blueshifts with the increase in Mn content and [Formula: see text] increases with the increase in Mn concentration. The resistivity and activation energy were measured at room temperature and ranging from 373 K to 573 K. Comparing to undoped ZnO thin film, the resistivity of Mn-doped ZnO films increased because of different parameters such as increasing barrier height energy and reducing the oxygen deficiency.

scholarly journals Methylene Blue Photodegradation under Visible Irradiation on Ag-Doped ZnO Thin Films

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
William Vallejo ◽  
Alvaro Cantillo ◽  
Carlos Díaz-Uribe
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Raman Spectroscopy ◽  
Photocatalytic Degradation ◽  
Physicochemical Characterization ◽  
Zno Thin Films ◽  
Visible Range ◽  
X Ray ◽  
Visible Irradiation ◽  
Doped Zno

This study synthesized and characterized Ag-doped ZnO thin films. Doped ZnO powders were synthesized using the sol-gel method, and thin films were fabricated using the doctor blade technique. The Ag content was determined by optical emission spectrometers with inductively coupled plasma (ICP plasma). Additionally, X-ray diffraction, Raman spectroscopy, Atomic Force Microscopy (AFM), diffuse reflectance, and X-ray photoelectron spectroscopy (XPS) measurements were used for physicochemical characterization. Finally, the photocatalytic degradation of methylene blue (MB) was studied under visible irradiation in aqueous solution. The Langmuir-Hinshelwood model was used to determine the reaction rate constant of the photocatalytic degradation. The physicochemical characterization showed that the samples were polycrystalline, and the diffraction signals corresponded to the ZnO wurtzite crystalline phase. Raman spectroscopy verified the ZnO doping process. The AFM analysis showed that roughness and grain size were reduced after the doping process. Furthermore, the optical results indicated that the presence of Ag improved the ZnO optical properties in the visible range, and the Ag-doped ZnO thin films had the lowest band gap value (2.95 eV). Finally, the photocatalytic degradation results indicated that the doping process enhanced the photocatalytic activity under visible irradiation, and the Ag-doped ZnO thin films had the highest MB photodegradation value (45.1%), as compared to that of the ZnO thin films (2.7%).

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.

Effect of Deposition Time on Structural and Optical Properties of ZnO Thin Films Deposited by Spray Pyrolysis

2019 ◽  
Vol 397 ◽  
pp. 81-87 ◽  
Author(s):  
Farid Khediri ◽  
Abdelkader Hafdallah ◽  
Mouna Bouhelal
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spray Pyrolysis ◽  
Deposition Time ◽  
Spray Pyrolysis Technique ◽  
Precursor Solution ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray

In this work Zinc oxide thin films prepared by spray pyrolysis technique. A set of ZnO thin films were deposited with various deposition times, on glass substrate at 350 °C. The precursor solution is formed with zinc acetate in distilled methanol with 0.1 molarity. The deposition time was ranged from 2 to 8 min. The structural and optical properties of those films were examined by X-ray diffraction (XRD) and ultraviolet-visible spectrometer (UV). X-ray diffraction patterns of the ZnO thin films showed polycrystalline hexagonal wurtzite structure and the preferred orientation was along (002) plane when the grain size varied between 9.66 and 16.67nm. ZnO thin films were highly transparent in the visible with the maximum transmittance of 85% and the optical band gap was found between 3.25 and 3.28 eV.

Ni-Doped ZnO Thin Films: Deposition, Characterization and Photocatalytic Applications

2021 ◽  
Vol 21 (3) ◽  
pp. 1560-1569
Author(s):  
K. Moorthy ◽  
S. S. R. Inbanathan ◽  
C. Gopinathan ◽  
N. P. Lalla ◽  
Abdulaziz Ali Alghamdi ◽  
...  
Keyword(s):  
Thin Films ◽  
Uv Light ◽  
Characteristic Root ◽  
Film Surface ◽  
Hexagonal Wurtzite Structure ◽  
Zno Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Doped Zno

Root like structured Ni-doped zinc oxide [Zn(1-x)NixO (x = 0.09)] thin films were deposited on a non-conducting glass substrate by indigenously developed spray pyrolysis system at optimized substrate hotness of 573±5 K. Thus obtained Ni-doped ZnO thin films were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Atomic Force Microscopy (AFM). XRD result revealed that Ni-doped ZnO has a polycrystalline nature with a hexagonal wurtzite structure. For pure ZnO and Ni-doped ZnO thin films, the particle sizes were 60.9 and 53.3 nm while lattice strain values were 1.56×10−3 and 1.14×10−3, respectively. The film surface showed characteristic root-like structure as observed by the SEM. It was observed that the Ni-doped ZnO thin films were grown in high density along with more extent of branching as compared to pure ZnO thin films but retained the root-like morphologies, however, the branches were more-thinner and of shorter lengths. AFM analysis showed that the surface grains of the Ni-doped samples are homogeneous with less RMS roughness values compared with the undoped ZnO samples. The photocatalytic activity of the prepared thin films was evaluated by the degradation of methyl orange (MO) dye under UV light irradiation. Pure ZnO and Ni-doped ZnO thin films took 150 min and 100 min to degrade about 60% MO dye, respectively.

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.

Optical and Electrical Characteristic of Layer-by-Layer Sol-Gel Spin Coated Nanoparticles ZnO Thin Films

2011 ◽  
Vol 364 ◽  
pp. 149-153 ◽  
Author(s):  
Shafinaz Sobihana Shariffudin ◽  
Farliana Samat Farah ◽  
Sukreen Hana Herman ◽  
Mohamad Rusop
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Reference Sample ◽  
Zno Thin Films ◽  
Visible Range ◽  
Zno Films ◽  
Layer By Layer ◽  
Voltage Measurement ◽  
Vis Spectroscopy ◽  
Reference Samples

Transparent nanoparticles ZnO thin films have been deposited on glass substrates using sol-gel spin coating technique. 0.35M sol were prepared by dissolving zinc acetate dehydrate in 2-methoxyethanol with monoethanolamine as the stabilizer. In this paper, a novel method called layer-by-layer is introduced, where the thin film is not only dried after each layer is spin-coated, but also directly annealed at 500°C to improve the electrical and optical properties of the films. Samples without annealing were also prepared as the reference sample. ZnO thin films were characterized using current-voltage measurement, UV-Vis spectroscopy and photoluminescence spectroscopy. The results revealed that layer-by-layer ZnO thin films have lower resistivity compared to the reference samples with a maximum value of 0.77Ω.cm for ZnO films deposited with 2 layers. Transmittance spectra show that the films were transparent in the visible range above 400nm with range of 86%-98% for the layer-by-layer ZnO films. The optical band gaps were between 3.2 to 3.3eV for both layer-by-layer and the reference samples. PL spectra indicate that layer-by-layer method improves the crystallinity of the films.

scholarly journals Synthesis, Characterization and Antibacterial Application of ZnO Thin films

2021 ◽  
pp. 13-16
Author(s):  
A M Wagh and N U Patil
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Resistivity ◽  
Antibacterial Activity ◽  
Energy Gap ◽  
Spray Pyrolysis Technique ◽  
Diffraction Method ◽  
Nano Particles ◽  
Zno Thin Films ◽  
Zno Film

The objective of this study is to synthesize ZnO nano particles in form thin film on glass substrate and study antibacterial active of such films. ZnO thin films were prepared by spray pyrolysis technique using zinc acetate and isopropyl alcohol as precursor in the temperature range 375̊C to 425̊C. The optical properties of the film were studied on UV/VIS/NIR spectrophotometer. The energy gap of the film is evaluated and it is found to be 3.31 eV. The polycrystalline nature of the ZnO film was confirmed by structural analysis by Xray diffraction method and the grain size is determined. It is found to be 50nm. The electrical resistivity of the film was measured by four probe method at different temperatures and it is found that electrical resistivity varying in the range 103 to 104 Ω–cm. we studied the antibacterial activity of ZnO thin film against gram-negative bacteria. Escherichia coli (E- coli) were used as test micro organisms. It is found that ZnO film enhanced the significant antibacterial activity.

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