Synthesis and Characterization of ZnO Nanoparticles (original) (raw)
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ZnO nanoparticles for solar cell applications
ZnO nano particles are deposited on p-Si substrate by sol-gel process. The intended application for such structures is photovoltaics. ZnO nano particles are also being explored for organic solar cells. The effect of precursor concentration on the surface morphology and structure of the ZnO nano particles are investigated. XRD analysis confirms the growth of ZnO with wurtzite (hexagonal) structure. The SEM results show variation in grain size in the range of 30 to 150 nm for nano particles obtained from sols with different precursor concentration.
ZnO nanoparticles synthesized by co-precipitation method; Morphology and optoelectronic study
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In this study, zinc oxide (ZnO) nanoparticles (NPs) were first synthesized using the co-precipitation method at the presence of Zn(NO3)2.6H2O precursor and calcined at 450 °C and 1000 °C. Then, the samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The XRD analysis was performed to evaluate the crystal structure. SEM and TEM analyses were also conducted to assess the morphology and the particle size of the material. Finally, the chemical compositions of the samples were investigated by energy dispersive x-rays (EDX) analyses. In this work, the crystallite Polygon shape ZnO NPs were fabricated in the range of 70-100 nm. We found that the intensity of the crystal plane of (002) increased by raising the temperature to 1000 °C.
Abstract: ZnO nanoparticles for different thermal treatment temperatures were prepared by using sol–gel method under supercritical drying of ethyl alcohol. The structural properties showed that the ZnO nanoparticles exhibit hexagonal wurtzite structure. Thus, in the case of thermal treatment at 500 °C in air, the powder with an average particle size of 40 nm shows a strong luminescence band around 384 nm in the UV range. However, the optical band gap of our samples varied between 3.34 and 3.21 eV with increasing annealing temperature. The imaginary and real parts of the sample impedance versus frequency, were studied in the range of 40 Hz–2 MHz. The Nyquist diagrams were used to identify an equivalent circuit and the fundamental parameters of the circuit. The characteristics of crystallinity, morphology, photoluminescence and electrical conductivity of ZnO nanoparticles were investigated.
An Empirical Study on Structural, Optical and Electronic Properties of ZnO Nanoparticles
In this work, the synthesis routes for zinc oxide (ZnO) nanoparticles and optical & electronic properties of ZnO nanoparticles have been demonstrated. ZnO has many potential applications including sunscreens, biosensors, food additives, pigments, rubber manufacture, and electronic materials. Because of the unique quantum confinement effects of ZnO nanoparticles, synthesis and characterization of ZnO nanoparticles has been received a great attention in contemporary materials science. The synthesized ZnO materials can be further characterized by many characterization techniques in order to confirm synthesis. In this case, X-ray diffraction (XRD is a very powerful tool to analyse the structure of the material. Surface characterization such as Scanning Electron Microscopy (SEM) and Transmission electron microscopy (TEM)could be very useful to understand the morphology of the nanoparticles. Also, Fourier transform infrared spectroscopy (FTIR) is helpful to identify particular chemical bonding in the synthesized materials. Thermal stability and thermal transition can be measured by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The optical properties of ZnO nanoparticles can be measured by UV-VIS spectroscopy.
Japanese Journal of Applied Physics, 2012
ZnO nanoparticles were synthesized using sol-gel method. The structural and optical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM), Raman spectroscopy, and photoluminescence (PL). XRD analysis demonstrates that the nanoparticles have the hexagonal wurtzite structure and the particle size is increased with annealing temperature. The average size of the nanoparticles was determined by SEM as well as XRD data and found to be 50 nm after annealing at 800 C. A sharp, strong and dominant UV emission with a suppressed green emission has been observed at 300 and 10 K, indicating the good optical properties of ZnO nanoparticles. The 10 K UV band is dominated by a neutral-donor bound exciton, and the surface-related SX emission at 3.31 eV is evidenced. #
Structural and Optical Properties of Zno Nano Particles
IOSR Journal of Applied Physics, 2014
In the present report preliminary studies on synthesis and growth of ZnO nanocrystals have been reported. ZnO precursors were prepared by precipitation method from Zinc nitrate and Ammonia in aqueous solutions at a pH value9.0 .ZnO nanocrystals were then synthesized by heating the precursor in a muffle furnace at temp 350°C for 3 hours and allowed to cool to room temperature. The precursors and synthesized nanoparticles were characterized by X-Ray diffraction (XRD) and the results showed a single phase wurtzite structure for ZnO nanoparticles. It was found that the synthesized ZnO nanocrystals have wurtzite structures with a=b=3.214 Å and c=5.154 Å. Crystallite size was calculated using Debye_Scherrer's equation and the average crystallite size from first three peaks was found to be 55.18 nm. The morphology of prepared ZnO nanopowders was characterized by scanning electron microscope (SEM). From the compositional analysis by Energy dispersive analysis of X-ray (EDX) it was confirmed that Zinc and oxygen are present in the sample. Optical characterization was done to study other characters. Diffuse reflectance spectroscopy (DRS) results shows that the band gap of ZnO nanoparticles is 3.20eV.
Effect of Cu Doping on Structural and Optical Properties of ZnO Nanoparticles Using Sol–Gel Method
Macromolecular Symposia, 2019
ZnO has large exciton binding energy (60 meV) and wide direct band gap (3.37 eV). It is a promising base materials for optoelectronics applications. To optimize its optical properties, Cu doped ZnO is synthesized by low cost sol-gel method and analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-vis spectroscopy. The XRD analysis reveals that the samples are polycrystalline with hexagonal wurtzite structure. It also indicates that there is no impurity peaks present in prepared samples and shows that the samples are stoichiometric. SEM images of Cu doping exhibit a slight variation in grain size. In addition, the absorption spectrum of pure and Cu doped ZnO nanoparticles (NPs) are studied and Tauc plots show band gap narrowing effect on Cu doping concentration to use it as advance material in diiferent devices.
SYNTHESIS AND CHARACTERIZATION OF ZnO NANOPARTICLES BY PRECIPITATION METHOD
IAEME PUBLICATION, 2019
Zinc oxide (ZnO) is an important semiconductor material that is used in the production of various industrial products. This paper describes the preparation of ZnO nanoparticles via chemical precipitation method. In precipitation method, the zinc nitrate solution is drop into aqueous sodium hydroxide, NaOH as precipitating agent. ZnO nanoparticles were synthesized by chemical precipitation method and calcinated at 500°C. The structural and optical characterization of ZnO nanoparticles were studied with X-ray Dif ractometer and UV-Visible spectroscopy respectively. X- ray dif raction pattern exhibit the polycrystalline nature with hexagonal wurtzite structure having the preferred orientation along (002) plane. The optical results describe the maximum absorption wavelength at 388 nm and the optical band gap is3.19 Ev.
Effect of Mn doping on structural and optical properties of sol gel derived ZnO nanoparticles
Journal of Luminescence, 2014
Un-doped and Mn-doped ZnO nanoparticles were successfully synthesized in an ethanolic solution by using a sol-gel method. Material properties of the samples dependence on preparation conditions and Mn concentrations were investigated while other parameters were controlled to ensure reproducibility. It was observed that the structural properties, particle size, band gap, photoluminescence intensity and wavelength of maximum intensity were influenced by the amount of Mn ions present in the precursor. The XRD spectra for ZnO nanoparticles show the entire peaks corresponding to the various planes of wurtzite ZnO, indicating a single phase. The diffraction peaks of doped samples are slightly shifted to lower angles with an increase in the Mn ion concentration, signifying the expansion of the lattice constants and increase in the band gap of ZnO. All the samples show the absorption in the visible region. The absorbance spectra show that the excitonic absorption peak shifts towards the lower wavelength side with the Mn-doped ZnO nanoparticles. The PL spectra of undoped ZnO consist of UV emission at 388 nm and broad visible emission at 560 nm with varying relative peak intensities. The doping of ZnO with Mn quenches significantly the green emission while UV luminescence is slightly affected. 78.55.-m; 78.67.-n