scholarly journals Doping Efficiency in Cobalt-Doped ZnO Nanostructured Materials

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Amrit Kaphle ◽  
Travis Reed ◽  
Allen Apblett ◽  
Parameswar Hari
Keyword(s):  
Inductively Coupled Plasma ◽  
Cobalt Chloride ◽  
Zno Nanorods ◽  
Precursor Solution ◽  
Xrd Analysis ◽  
Cobalt Nitrate ◽  
Hexagonal Structure ◽  
Sem Images ◽  
Substantial Impact ◽  
Glass Substrates

Nanostructured ZnO thin films doped with cobalt from 5% to 20% were grown on glass substrates by a low-temperature chemical bath deposition (CBD) technique. We compared the doping efficiency of incorporating cobalt in ZnO nanostructured samples doped with cobalt via cobalt nitrate and cobalt chloride. The concentration of cobalt incorporated into the ZnO matrix was precisely determined using inductively coupled plasma mass spectroscopy (ICP-MS). Scanning electron microscopy (SEM) images showed that only at a 0.1 M ratio of the precursor solutions in CBD using cobalt nitrate as a dopant, the morphology of ZnO yielded hexagonally shaped nanorods. At a 1 M ratio of the precursor solutions, SEM images showed that the morphology of ZnO was nanoplatelets at all doping levels, irrespective of the doping method used. The synthesized nanostructures retained the wurtzite hexagonal structure only at 0.1 M precursor solution using cobalt nitrate doping, which was confirmed by X-ray diffraction (XRD) studies. In cobalt-doped samples using cobalt chloride as a dopant, XRD analysis confirmed the formation of a Simonkolleite structure. At 300°C, the Simonkolleite structure was converted to a wurtzite structure without changing the morphology. Electrical conductivity measurements at 300 K showed that ZnO nanorods doped with cobalt using cobalt nitrate yielded the lowest resistivity. The molarity of the precursor solution and dopant was found to have a substantial impact on the morphology and doping efficiency of the ZnO nanostructures.

OPTICAL, STRUCTURAL, AND MORPHOLOGICAL PROPERTIES OF UNDOPED AND EUROPIUM DOPED ZnO

2019 ◽  
Vol 27 (03) ◽  
pp. 1950114 ◽  
Author(s):  
F. TOURI ◽  
A. SAHARI ◽  
A. ZOUAOUI ◽  
F. DEFLORIAN ◽  
L. GUERBOUS
Keyword(s):  
Indium Tin Oxide ◽  
Zno Nanorods ◽  
Precursor Solution ◽  
Xrd Analysis ◽  
Unit Cell ◽  
Morphological Properties ◽  
Diffusion Control ◽  
Zno Films ◽  
Sem Images ◽  
Doped Zno

Undoped and europium doped ZnO films were electrodeposited from precursor solution on indium tin oxide (ITO) surfaces. Undoped ZnO nanorods were successfully obtained and grown under diffusion control perpendicularly ([Formula: see text] axis) on the ITO surface. The X-ray diffraction (XRD) analysis showed a wurtzite structure with sizes of the hexagonal unit cell: [Formula: see text][Formula: see text]Å [Formula: see text] and [Formula: see text][Formula: see text]Å. After insertion of Eu[Formula: see text] into the ZnO matrix, XRD analysis shows a shift of preferential peak to lower angles (2[Formula: see text] indicating that a dislocation occurs into the unit cell with modification of its parameters. The grain sizes of doped ZnO decrease with increasing Eu[Formula: see text] rate. Scanning electron microscopy (SEM) images show a clear change of morphological structure from nanorods to a nanosheet structure. Photoluminescence tests clearly showed an improvement in emission bands and the corresponding intensities are important in Eu[Formula: see text] doped ZnO.

Morphological, Structural, Electrical and Optical Properties of Copper-Doped Zinc Oxide Films Deposited by Spray Pyrolysis

2018 ◽  
Vol 930 ◽  
pp. 79-84
Author(s):  
Juliana Simões Chagas Licurgo ◽  
Herval Ramos Paes Junior
Keyword(s):  
Zinc Oxide ◽  
Spray Pyrolysis ◽  
Oxide Films ◽  
Electrical Characterization ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
Hexagonal Structure ◽  
Material Behavior ◽  
Glass Substrates ◽  
Zinc Oxide Films

In this work, copper-doped zinc oxide films (ZnO:Cu) were deposited by spray pyrolysis on glass substrates. The influence of doping concentration (0-10 at.%) on morphological, structural, optical and electrical properties of the ZnO:Cu films was investigated. Electrical characterization consisted in measuring the variation of electrical conductivity with temperature; they presented a typical semiconductor material behavior. Based on x-ray diffraction (XRD) analysis, it was able to confirm that the films are polycrystalline having a wurtzite hexagonal structure, preferentially oriented in the c-axis (002), and the crystallite size ranged from 41.60 to 50.70 nm. The optical characterization revealed that ZnO:Cu films present band gap energy between 3.18 and 3.27 eV. The films were homogeneous with good adhesion to the substrate. The results indicate the viability of using them in optoelectronic devices.

Influence of Sputtering Power on Molybdenum-Doped Zinc Oxide Films Grown by RF Magnetron Sputtering

2013 ◽  
Vol 873 ◽  
pp. 426-430
Author(s):  
Xian Wu Xiu ◽  
Li Xu ◽  
Cheng Qiang Zhang
Keyword(s):  
Zinc Oxide ◽  
Magnetron Sputtering ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
Hexagonal Structure ◽  
Visible Range ◽  
Rf Power ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Sputtering Power

Molybdenum-doped zinc oxide (MZO) films have been prepared by RF magnetron sputtering on glass substrates at room temperature. The structural, electrical and optical properties of the films vary with sputtering power from 15 W to 70 W are investigated. X-ray diffraction (XRD) analysis reveals that all the films are polycrystalline with the hexagonal structure and have a preferred orientation along thecaxis perpendicular to the substrate. The resistivity increases with the increase of the RF power. The lowest resistivity achieved is 5.4×10-3Ω cm at a RF power of 15 W with a Hall mobility of 11 cm2V-1s-1and a carrier concentration of 1.1×1019cm-3. The average transmittance drops from 85% to 81% in the visible range and the optical band gap decreases from 3.26 eV to 3.19 eV with the increase of the RF power.

scholarly journals Characterization of Ag/ZnO Nanorod Schottky Diode-Based Low-Voltage Ultraviolet Photodetector

NANO ◽  
2017 ◽  
Vol 12 (05) ◽  
pp. 1750063 ◽  
Author(s):  
Shaivalini Singh ◽  
S. Jit ◽  
Si-Hyun Park
Keyword(s):  
Indium Tin Oxide ◽  
Low Voltage ◽  
Zno Nanorods ◽  
Contrast Ratio ◽  
Cost Effective ◽  
Hexagonal Structure ◽  
Schottky Contacts ◽  
Uv Detection ◽  
Glass Substrates ◽  
Uv Illumination

Ultraviolet (UV) detection characteristics of Ag Schottky contacts with ZnO nanorods (ZnO-NRs) grown on Indium Tin Oxide (ITO)-coated glass substrates have been investigated. A low-temperature hydrothermal method was used for growing ZnO-NRs. Circular contacts of Ag were deposited above the ZnO-NRs/ITO samples using the shadow mask technique. The structural properties of the ZnO-NRs were characterized by using scanning electron microscopy (SEM), atomic force microscope (AFM) and X-ray diffraction (XRD). The results revealed a (0002) crystal orientation and a wurtzite hexagonal structure. The electrical characteristics of the Ag/ZnO-NR Schottky contacts were studied at forward applied bias over the range 0[Formula: see text]V to 1[Formula: see text]V, under dark and UV illumination. The dark and photocurrents were [Formula: see text][Formula: see text]A and [Formula: see text][Formula: see text]A, respectively, and the contrast ratio (ratio of photocurrent to dark current) was 1.67 at [Formula: see text]1.0[Formula: see text]V for these devices. The results show that these devices could be useful for cost-effective and low-voltage UV detection applications.

scholarly journals Surface and Morphological Features of ZrO2 Sol-Gel Coatings Obtained by Polymer Modified Solution

2020 ◽  
Vol 2 (1) ◽  
pp. 6
Author(s):  
Ognian Dimitrov ◽  
Irina Stambolova ◽  
Sasho Vassilev ◽  
Katerina Lazarova ◽  
Tsvetanka Babeva ◽  
...  
Keyword(s):  
Sol Gel ◽  
Precursor Solution ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Paramagnetic Resonance ◽  
Coating Method ◽  
Ft Ir ◽  
Zro2 Sol ◽  
Electron Paramagnetic

Thin, homogeneous ZrO2 films were obtained by spin coating method from ZrOCl2 8H2O solution, modified with polyethylene glycol (PEG) (Mw = 400). The films have thickness of 80 nm and refractive index of about 1.45, which varied with the amount of added PEG. The thermal behaviour of the precursor was studied with thermogravimetry and differential thermal analysis (TG-DTA). The X-ray diffraction (XRD) analysis revealed the presence of a mixture of monoclinic and tetragonal ZrO2 polycrystalline phases with nanosized crystallites. The formation of hydrogen bonds among the organic and inorganic components was proved by means of Fourier transform infrared spectroscopy (FT-IR) analysis, while the different defect centres were investigated with electron paramagnetic resonance (EPR) spectroscopy. The scanning electron microscopy (SEM) images showed that the samples are dense and crack-free, with ganglia-like nanostructure. It was established that the addition of polymer resulted in the introduction of free volume in the films, which also varied with the content of PEG in the precursor solution.

scholarly journals SYNTHESIS AND PHOTOLUMINESCENCE STUDIES ON ZINC OXIDE NANOWIRES

2017 ◽  
Vol 24 (1&2) ◽  
pp. 205-212
Author(s):  
Nguyen Ngoc Long ◽  
Ngo Xuan Dai ◽  
Nguyen Thi Thuc Hien
Keyword(s):  
Xrd Analysis ◽  
Hexagonal Structure ◽  
Zno Nanowires ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Simple Method ◽  
Oxide Nanowires ◽  
Lattice Constants ◽  
Zno Powders ◽  
Photoluminescence Studies

Semiconductor single crystal ZnO nanowires have been successfully synthesized by a simple method based on thermal evaporation of ZnO powders mixed with graphite. Metallic catalysts, carrying gases, and vacuum conditions are not necessary. The x-ray diffraction (XRD) analysis shows that the ZnO nanowires are highly crystallized and have a typical wurtzite hexagonal structure with lattice constants a = 0.3246 nm and c = 0.5203 nm. The scanning electron microscopy (SEM) images of nanowires indicate that diameters of the ZnO nanowires normally range from 100 to 300 nm and their lengths are several tens of micrometers. Photoluminescence (PL) and photoluminescence excitation (PLE) spectra of the nanowires were measured in the range of temperature from 15 K to the room temperature. Photoluminescence spectra at low temperatures exhibit a group of ultraviolet (UV) narrow peaks in the region 368 nm ~ 390 nm, and a blue-green very broad peak at 500 nm. Origin of the emission lines in PL spectra and the lines in PLE spectra is discussed.   

Effect of Temperature on Structural and Optical Properties of ZnO Nanorods by Hydrothermal Method

2013 ◽  
Vol 591 ◽  
pp. 293-296 ◽  
Author(s):  
Xiao Yan Fei ◽  
Jun Luo ◽  
Shu Wang Duo ◽  
Hao Zhang ◽  
Xiang Min Xu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Hydrothermal Method ◽  
Zno Nanorods ◽  
Hexagonal Structure ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Sem Images ◽  
Zno Crystal ◽  
Ir Study

The ZnO nanorods were prepared at 130 °C, 160 °C and 190 °C for 6 h by hydrothermal method. The structural and optical properties of ZnO nanorods were invesitigated by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). XRD pattern analysis showed that the ZnO nanorods are the hexagonal structure (space group P63 mc). No other crystal phases, such as Zn and Zn (OH)2 were detected. FT-IR study identified the sharp peak that appeared at 573 cm-1 is related with the ZnO stretching mode. Also, SEM images revealed that the diameter of a single ZnO crystal ranges from 100 to 300 nm and the length ranges from 1 to 3 μm.

scholarly journals Investigation on Al Doped Zno Thin Films and its N-Alzno/P-Si Junction Diodes Via Dip Coating and JNSP Techniques

2018 ◽  
Vol 34 (5) ◽  
pp. 2590-2596
Author(s):  
S. Kalidass ◽  
P. Thirunavukkarasu ◽  
M. Balaji ◽  
J. Chandrasekaran
Keyword(s):  
Thin Films ◽  
Xrd Analysis ◽  
Dip Coating ◽  
Band Gap Energy ◽  
Hexagonal Structure ◽  
Sem Images ◽  
X Ray ◽  
Maximum Conductivity ◽  
Jet Nebulizer ◽  
Doped Zno

From this investigation, we find out that the dip coating and jet nebulizer spray pyrolysis (JNSP) techniques are the suitable to fabricate aluminum doped zinc oxide (AlZnO) thin films and the P-N junction diode of n-AlZnO/p-Si at 450°C. Several characterization techniques are used to measure the consequences of Al doping (0, 0.5, 1.0, 1.5, 2.0 and 2.5 wt.%) on structural, optical, electrical and diode properties of ZnO. We recorded that the films were polycrystalline with a hexagonal structure of ZnO by the X-ray diffraction (XRD) analysis. The disparities of the sub-micro sized rod-like structures are observed from the scanning electron microscope (SEM) images. The energy dispersive X-ray spectroscopy (EDX) analysis proved that the elements of Al, Zn and O were presented in the film. The absorbance and band gap energy (Eg) values were ascertained from the ultraviolet visible (UV-vis) analysis. By the current-voltage (I-V) characterization, the maximum conductivity value is detected for 1.5 wt.% of Al doped ZnO film. The I-V measurement for finding the diode parameters of ideality factor (n) and barrier height (Fb) in dark and under light was taken.

scholarly journals Morphological, Structural, and Optical Bandgap Characterization of Extracted ZnO Nanoparticles from Commercial Paste

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Mahmoud Nabil ◽  
I. V. Perez-Quintana ◽  
M. Acosta ◽  
J. A. Mendez-Gamboa ◽  
R. Castro-Rodriguez
Keyword(s):  
Zno Nanoparticles ◽  
Average Crystallite Size ◽  
Hexagonal Wurtzite Structure ◽  
Xrd Analysis ◽  
Zno Nps ◽  
Sem Images ◽  
Visible Absorption ◽  
X Ray ◽  
Glass Substrates ◽  
Crystal Volume

ZnO nanoparticles (NPs) were extracted from a commercial paste in both colloidal and precipitate forms. The Zetasizer analysis performed on the colloid showed ZnO NPs ranging from ∼30 nm to ∼100 nm. Thin films of ZnO were deposited on glass substrates by spin-coating technique from a mixture of the extracted colloid and precipitate. The scanning electron microscope (SEM) images showed uniformly arranged, mesoporous, and nanostructured ZnO particles of different shapes, with an estimated film thickness of 0.67 μm. Analysis by energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD) confirmed the presence of ZnO in the films, with no impurities or remnants of other materials. The XRD analysis showed a polycrystalline nature of the films and identified a pure phase formation of the hexagonal wurtzite structure. The average crystallite size calculated from the diffraction peaks is ∼43.25 nm. The calculated crystal tensile strain is 1.954 × 10−3, which increases the crystal volume by 0.728% compared with the crystal volume of standard ZnO. The calculated crystal parameters are a = b = 3.258 Å and c = 5.217 Å. The calculated dislocation density (d) and bond length Zn–O (L) are 5.35 × 10−4 nm−2 and 2.695 Å, respectively. Ultraviolet-visible absorption spectra showed an optical band gap of ∼3.80 eV.

scholarly journals Growth and Characterizes of PbI2 Films By Vacuum Evaporation Method

2019 ◽  
Vol 30 (2) ◽  
pp. 60
Author(s):  
Mohammed S. Mohammed ◽  
Ghassq Dawood Salman ◽  
Khaleel I. Hassoon
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Near Infrared ◽  
Xrd Analysis ◽  
Hexagonal Structure ◽  
Lead Iodide ◽  
Thermal Evaporation Method ◽  
Evaporation Method ◽  
Glass Substrates ◽  
Iodide Film

In this work, thin films of lead iodide (PbI2) were deposited on glass substrates with different thicknesses by vacuum thermal evaporation method. The structural, chemical, electrical and optical characteristics of the thin films were studied. XRD analysis showed that lead iodide film is polycrystalline having hexagonal structure. A particle size was estimated by Williamson - Hall technique (13) nm and strain (4.90*10-3) are founded from the intercept with y-axis and slope for PbI2. The UV-VIS measurements illustrated that the lead iodide has a direct optical band gap and Urbach energy to be 0.677 eV2. Raman peaks are detected at 70, 96, 99.5, 188 and 202 cm-1 which corresponding to characteristic of PbI2 at (E21, A11, 2E11 and A1g). The FTIR spectrum of PbI2 thin film showed six bands at 1650, 1900, 3100, 3400, 3600 and 3800 cm-1. Mechanism of dc transport was also analyzed in the temperature range 315–395 K. Also the variation of reflectivity in the range near infrared is conductive generally attributed to thin film nature, where this film contain light scattering and large surface area, which enhance the optical absorption and hence, a low reflectivity is obtained.

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