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Hexagonal Wurtzite Structure (hexagonal + wurtzite_structure)
Selected AbstractsOptical properties of ZnO nanotubesCRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2010Hongju Zhai Abstract Tubular ZnO nanostructures have been obtained via a hydrothermal method at low temperature (90 °C) without any catalysts or templates. The XRD measurement reveals that the tubes are single crystals with hexagonal wurtzite structure. SEM shows that the diameters of ZnO nanotubes ranged from 400 to 550 nm. The Raman and PL spectra indicate that oxygen vacancies or Zn interstitials are responsible for the green emission in the ZnO nanotubes. A possible growth mechanism on the formation of crystalline ZnO nanotubes has been presented. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Enhanced ultraviolet photoluminescence from V-doped ZnO thin films prepared by a sol,gel processPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2007Ling Wei Abstract Undoped and vanadium-doped ZnO thin films were prepared on single-crystalline p-type Si(100) substrates by a sol,gel process and further annealed in an oxygen atmosphere. The influence of vanadium doping on the structural, surface morphological and optical properties of ZnO thin films was investigated by X-ray diffraction, atomic force microscopy and photoluminescence measurements. Both the undoped and V-doped ZnO thin films were of polycrystalline hexagonal wurtzite structure with (002)-preferred orientation. The crystallite size and the root-mean-square roughness of V-doped ZnO are smaller than those of undoped ZnO. Vanadium doping could reduce deep level defects of ZnO and thus strengthen ultraviolet (UV) emission. The peak intensity of UV emission increased with increasing annealing temperature above 400 °C. After annealing at 800 °C, the UV emission for the V-doped ZnO films was largely enhanced, while the visible emission was distinctly weakened. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Influence of annealing temperature on the structural and optical properties of sol,gel prepared ZnO thin filmsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 10 2006Mingsong Wang Abstract Zinc oxide thin films have been prepared via a sol,gel process. The influence of annealing temperature on the structural and optical properties of the ZnO thin films has been investigated. The prepared ZnO thin films had a polycrystalline hexagonal wurtzite structure with no preferred orientation. The annealing temperature had a great effect on the optical properties of the ZnO thin films: the optical band gap became narrow due to the increase in crystallite size and the reduction in amorphous phase amount with increasing annealing temperature. Absorption or desorption of oxygen in the annealing process caused the observed yellow or green emission. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Growth and characterization study of multidimensional hierarchical ZnO nanostructuresPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2007Dong Jun Park Abstract ZnO multidimensional hierarchical structure was successfully fabricated with the sequence of ZnO top layers/ZnO nanorods/ZnO buffer/Si(111) substrate by continuous controlling growth condition in metal organic chemical vapor deposition (MOCVD) system. Transmission electron microscopy (TEM) showed that ZnO nanorods in hierarchical structure had a single crystal hexagonal wurtzite structure with ,0001,ZnO growth direction. Only near band edge (NBE) emissions with very weak deep level emission are observed around 3.28 eV. This indicates that ZnO hierarchical structure grown by MOCVD shows a good optical quality and less interior defects. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||