Microstructural Analysis and the Multicolor UV/Violet/Blue/Green/Yellow PL Observed from the Synthesized ZnO Nano-leaves and Nano-rods
| Autor: | Ivana Lj. Validžić, S. Phillip Ahrenkiel, Mirjana I. Čomor, Miodrag Mitrić |
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| Rok vydání: | 2015 |
| Předmět: |
010302 applied physics
Photoluminescence Materials science Rietveld refinement Band gap business.industry Metallurgy Metals and Alloys Analytical chemistry 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics medicine.disease_cause 01 natural sciences Mechanics of Materials Transmission electron microscopy 0103 physical sciences medicine Optoelectronics Diffuse reflection Crystallite 0210 nano-technology business Powder diffraction Ultraviolet |
| Zdroj: | Metallurgical and Materials Transactions. A: Physical Metallurgy and Materials Science |
| ISSN: | 1543-1940 1073-5623 |
| DOI: | 10.1007/s11661-015-2961-x |
| Popis: | We report the synthesis of zinc oxide (ZnO) nano-leaves and nano-rods under high and extremely high alkaline experimental conditions, via a simple and low-temperature method. By performing transmission electron microscopy it is found that the nano-leaves and nano-rods grow along the (001) direction. Anisotropic, i.e., hkl-dependent line-shape broadening is observed in ZnO powder diffraction patterns. Rietveld analysis using Fullprof with model for handling the anisotropic size-like broadening is performed on these diffraction patterns. The refinement showed that ZnO powders belong to the hexagonal ZnS structure type with space group P63mc, and confirmed that the nano-leaves and nano-rods are oriented along the (001) direction. Results of visualization in 3D of the average crystallite shape obtained from refinement of spherical harmonics coefficients showed elongated shapes in the both samples, exhibiting a slight twisting for nano-leaves. Diffuse reflectance measurements reveal that the optical band-gap energies found for the ZnO nano-leaves and nano-rods is somewhat smaller than a wide-direct band gap of 3.37 eV. We argued that well defined and strong photoluminescence (PL) bands in the visible part that belong to the defects may influence the observed displacement of a ultraviolet (UV) near-band-edge emission, and which is related with obtained slightly lower band-gap energies than the established band gap of bulk ZnO. We discuss processes behind the multicolor UV/violet/blue/green/yellow emission band in PL spectra. (C) The Minerals, Metals and Materials Society and ASM International 2015 |
| Databáze: | OpenAIRE |
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