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Title: Structural- and optical-property characterization of three-dimensional branched ZnO nanospikes

Current study reports the synthesis of three-dimensional (3-D) ZnO nanospikes with anomalous optical property, where zinc stearate is adopted as a safe, common and low-cost precursor that undergoes thermal pyrolysis under non-hydrolytic approach. High resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) result show that the as-synthesized 3-D ZnO nanospikes are constructed by bundle of nanorods that sprout radially outwards in random orientation. The possible growth mechanism is discussed by referring to the microscopy results. X-ray diffraction (XRD) pattern confirms that the nanospikes are highly crystalline, which existed in hexagonal wurtzite crystal structure. Optical absorption characterization shows that the onset absorption for the nanospikes is slightly red-shifted if compared to commercial ZnO and the corresponding bandgap energy is estimated to be 3.1 eV. The photoluminescene (PL) result of ZnO nanospikes indicate that its optical emission exhibits weak UV emission but very intense visible-light emission that ranged from green- up to red-region. The factors that contributed to the intriguing PL characteristic are discussed. Current finding would offer a versatile synthesis scheme in engineering advanced nanostructures with new design that exhibit congruent optical property. - Graphical abstract: Display Omitted - Highlights: • Pyrolysis of zinc stearate in synthesizing 3-D ZnOmore » nanospikes • ZnO nanospikes possess bundle of nanorods that sprout out from the hexagonal stump • Growth mechanism is deduced to elucidate the morphological evolution from nanobullet to nanospike with branching topology • PL spectrum indicate that the nanospike exhibit prominent visible-light emission that ranged from green- to red-region.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2] ; ; ;  [3]
  1. Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University Malaya, 50603, Lembah Pantai, Kuala Lumpur (Malaysia)
  2. Faculty of Engineering, University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor (Malaysia)
  3. School of Applied Physics, Faculty of Science & Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)
Publication Date:
OSTI Identifier:
22476133
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 106; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; BRANCHING RATIO; EMISSION; EVOLUTION; NANOSTRUCTURES; OPTICAL PROPERTIES; PYROLYSIS; RED SHIFT; SCANNING ELECTRON MICROSCOPY; SPECTRA; SYNTHESIS; THREE-DIMENSIONAL CALCULATIONS; TRANSMISSION ELECTRON MICROSCOPY; VISIBLE RADIATION; X-RAY DIFFRACTION; ZINC OXIDES