Wurtzite Structure Of Zinc Oxide Research Articles

Synthesis of nanocrystalline zinc manganese oxide by thermal decomposition of new dinuclear manganese(III) precursors

Nanocrystalline manganese-doped zinc oxide was synthesized by thermal decomposition of a zinc oxide sol with two new dinuclear manganese(III) complexes as precursor. Thermal analysis results indicated that the decomposition of manganese precursors occurred at 269 and 314 °C. X-ray structural analysis shows the presence of dimanganese core in the complexes and the binding of the ligands to the manganese(III) is through N2O2. The manganese-doped zinc oxide composite was characterized by means of X-ray diffraction, scanning electron microscopy, and UV–Vis spectroscopy. Structural properties of the composites elucidated that the manganese ions have substituted the zinc ions without changing the wurtzite structure of zinc oxide.

Implementation of High Carrier Mobility in Al-N Codoped p-Type ZnO Thin Films Fabricated by Direct Current Magnetron Sputtering with ZnO:Al2O3Ceramic Target

In this study, Al-N codoped p-type zinc oxide (ZnO) thin films were deposited on Si and homo-buffer layer templates in a mixture of and gas with ceramic ZnO:(2 wt% ) as a sputtering target using DC- magnetron sputtering. X-ray diffraction spectra of two-theta diffraction showed that all films have a predominant (002) peak of ZnO Wurtzite structure. As the fraction in the mixed and gases increased, field emission secondary electron microscopy revealed that the surface appearance of codoped films on Si varied from smooth to textured structure. The p-type ZnO thin films showed carrier concentration in the range of , resistivity in the range of 131.2-2.864 , and mobility in the range of respectively.

Synthesis of ZnO Polycrystalline Flakes Using Sol-Gel Method

This study proposes a novel sol-gel method of fabricating the two-dimensional flakes polycrystalline zinc oxide (ZnO). Apply zinc acetate dehydrate in glycerol and hydrolyzed to get the precursor zinc alkoxide particles at 160°C, and self-assemble into flakes ZnO nanostructures, and then got higer crystallinity polycrystalline ZnO after calcination for one hour at 500°C. Field-emission scanning electron microscopy (FE-SEM) was used to observe the morphology of the flakes. Its size got to a few μm2. Analyze the crystal structure and crystallinity by X-ray powder diffraction (XRD). After calcination for one hour at 500°C, we can determine it is the hexagonal wurtzite structure of ZnO. And TGA/DSC to observe the loss and phase change of the solution. The Study has successfully synthesized ZnO polycrystalline flakes by sol-gel method.

Nanostructure and optical properties of M doped ZnO (M=Ni, Mn) thin films prepared by sol–gel process

The transparent thin films of undoped, Mn-doped, and Ni-doped zinc oxide (ZnO) have been deposited on glass substrates via sol–gel technique using zinc acetate dehydrate, nickel chloride, and manganese chloride as precursors. The structural properties and morphologies of the deposited undoped and doped ZnO thin films have been investigated. X-ray diffraction (XRD) spectra, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) were used to examine the morphology and microstructure of the thin films. Optical properties of the thin films were determined by photoluminescence (PL) and UV/vis spectroscopy. The analyzed results indicate that the obtained films are of good crystal quality and have smooth surfaces, which have a pure hexagonal wurtzite ZnO structure without any Mn or Ni related phases. The band gap energy was estimated by Tauc's method and found to be 3.28, 3.26, and 3.34 eV for ZnO, Ni-doped ZnO, and Mn-doped ZnO thin films at room temperature, respectively. Room temperature photoluminescence is observed for the ZnO, Ni-doped ZnO, and Mn-doped ZnO thin films.

ZnO nanostructures growth with silver catalyst—Effect of annealing

Zinc oxide (ZnO) nanostructures have been grown on both the as-deposited silver thin-film templates over silicon substrates and annealed silver thin-film templates on silicon substrates. ZnO was grown by evaporation of metallic zinc over the silver templates followed by thermal annealing in air. Sword-like ZnO nanostructures grew densely throughout the surface of the annealed silver template sample. A small number of ZnO swords embedded in a porous surface were found for the as-deposited silver template sample. It is observed that the annealing treatment of the Ag thin-film is the key factor in controlling the formation of ZnO nanostructures. XRD study shows that the nanostructures have very good crystallinity and have the hexagonal wurtzite ZnO structure. The room-temperature photoluminescence spectrum indicates that the nanostructures grown on annealed Ag template are less defective and have high optical quality. On the other hand, a very weak UV emission peak and the blue emission doublet band reveal that the ZnO sample grown on the as-deposited silver template are highly defective. The micro-Raman spectra of the ZnO nanostructures grown on both types of Ag templates show enhanced Raman scattering which is related to surface enhanced Raman scattering (SERS).

The effects of ZnO coating on the photoluminescence properties of porous silicon for the advanced optoelectronic devices

In the present work we investigate, the role of zinc oxide (ZnO) thin films passivating layer deposited by rf magnetron sputtering at room temperature on low (18%) and high (80%) porosity porous silicon (PS). The micro-Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) analysis have been carried out to understand the effect of ZnO films coating on PS. A systematic investigation from Raman spectroscopy suggests the formation of a good quality ZnO wurtzite structure on PS. The photoluminescence (PL) measurements on PS and ZnO coated PS shows a red, blue and UV emission bands at around ∼1.8, ∼2.78 and ∼3.2eV. An enhancement of all PL emission bands have been achieved after ZnO films deposition on high porosity PS.

Synthesis and characterization of mercaptoacetic acid-modified ZnO nanoparticles

Mercaptoacetic acid (MAA)-modified ZnO nanoparticles have been prepared at low temperature by homogeneous precipitation method, using zinc nitrate hexahydrate and hexamethylenetetramine as initial agents. The modified zinc oxide nanorods were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric (TG) analysis and photoluminescence (PL) spectroscopy. The XRD revealed the wurtzite structure of zinc oxide. The growth of ZnO crystals into rod shape was found to be closely related to its hexagonal nature. As indicated from SEM, the morphology of the modified ZnO nanorods changes with various MAA addition times. In addition, the results of TG and FT-IR confirmed the conjugation of MAA with ZnO nanorods, and the amount of carboxyl group in the samples' surface was found to be 0.1943–0.3491 mmol/g through the titration experiment. The PL spectra indicated that the optical properties of ZnO nanorods were changed with the insertion of MAA, and showed a significant improvement in intensity. On the basis of these results, one might expect that the conjugate specific biomolecules on the functional ZnO nanorods are very potential to detect the complementary biomolecules by PL detecting.

Quantitative microstructural and spectroscopic investigation of inversion domain boundaries in sintered zinc oxide ceramics doped with iron oxide

Abstract It is known that sintering of powders of zinc oxide (ZnO) with small additions of iron oxide results in a ceramic with grains exhibiting a characteristic inversion domain microstructure with planar inversion domain boundaries (IDBs) on two different habit planes. This study concentrates on a quantitative analysis, by a combination of different transmission electron microscopy methods, of those IDBs that are parallel to {0001} basal planes of the wurtzite structure of ZnO. Electron diffraction and dark-field imaging prove the nature of the inversion. High-resolution annular dark field scanning transmission electron microscopy allows measurement of the rigid body displacements across these IDBs and of the local lattice contraction related to the octahedral interstices that form the boundaries. Energy-selected imaging, electron energy-loss spectroscopy and energy-dispersive X-ray spectroscopy have been combined to determine the chemical composition of the IDBs quantitatively. It is thus shown unambi...

Spectroscopic characterization of zinc oxide nanorods synthesized by solid-state reaction

Well-crystallized zinc oxide nanorods have been fabricated by single step solid-state reaction using zinc acetate and sodium hydroxide, at room temperature. The sodium lauryl sulfate (SLS) stabilized zinc oxide nanorods were characterized by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and photoluminescence spectroscopy. The X-ray diffraction revealed the wurtzite structure of zinc oxide. The size estimation by XRD and TEM confirmed that the ZnO nanorods are made of single crystals. The growth of zinc oxide crystals into rod shape was found to be closely related to its hexagonal nature. The mass ratio of SLS:ZnO in the nanorods was found to be 1:10 based on the thermogravimetric analysis. Blue shift of photoluminescence emission was noticed in the ZnO nanorods when compared to that of ZnO bulk. FT-IR analysis confirmed the binding of SLS with ZnO nanorods. Apart from ease of preparation, this method has the advantage of eco-friendliness since the solvent and other harmful chemicals were eliminated in the synthesis protocol.

The effect of cobalt oxide on zinc oxide in a new anticorrosive green pigment

Purpose – Aims to study inhibitive properties of new compounds that are based on the Wurtzite structure of zinc oxide with an admixture of cobalt using zinc oxide as a reference.Design/methodology/approach – The conditions for the preparation of pigments using different ratios of both cobalt and zinc were investigated. Characterization of these pigments was carried out using spectroscopic methods of analysis via X‐ray diffraction, transmission and scanning electron microscopy. Also, evaluations of the pigments prepared, in terms of oil absorption, specific gravity, water‐soluble matter and pH, using international standard testing methods was performed. The pigments prepared were incorporated in anticorrosive paint formulations based on medium oil alkyd resin as a binder. The physico‐mechanical properties of the relevant paint films were obtained, while their anticorrosive properties were assessed by tests in 3.5 percent NaCl solution for 28 days. Electrochemical measurements based on corrosion rates of pa...

Morphology and fine structure of zinc electrodeposits

Abstract A 'nanolaminated' structure has been observed in electrodeposited Zn by using high-resolution transmission electron microscopy. It has been found that the individual Zn crystallites in the deposits are all bounded by an ultra-thin zinc oxide (ZnO) layer about 3·5 nm in thickness. The crystallites are predominantly hexagonal platelet shaped, typically 300 nm in diameter and 50 nm in thickness. The presence of grains with a specific hexagonal geometry in the deposit results from a layered texture, which is made by a repeated sandwich-like epitaxial growth between Zn (hexagonal) and ZnO (wurtzite structure). Such a structural growth pattern is discussed in terms of the kinetics of the electrodeposition process. It is proposed that Zn deposition occurs from zinc hydroxide (Zn(OH)2) which forms close to the metal-electrolyte interface as a result of H2 evolution and the local increase in electrolyte pH. The interaction between the depletion of the Zn(OH)2 colloidal layer due to Zn deposition and its r...

Polare Eigenschaften von Zinkoxid-Kristallen

A polarc-axis must be attributed to the wurtzite structure of zinc oxide. The sign of thec-axis can be determined by cleaving perpendicular to this axis and subsequent etching of the exposed {0001} surfaces. The present paper reports how this can be achieved without cleavage, merely by etching the prism faces {10¯10} which are the principal surfaces of hexagonal needles and of thin platelets. The etch patterns unambiguously point into the direction of the positivec-axis. This method is applied not only to the prism faces but also to cleaved surfaces of the same orientation. A close relation between etch patterns and lattice defects is apparent.