9-13 July 2012
Structural, morphological and luminescence properties of hexagonal ZnO particles by wet chemical process
Presented by Prof. Francis DEJENE on 10 Jul 2012 from 17:30 to 19:30
Type: Poster Presentation
Session: Poster Session
Track: Track A - Division for Condensed Matter Physics and Materials
ZnO particles of different sizes were synthesized using a simple wet chemical method. This is a very attractive method, inexpensive and convenient for large area deposition. It is a low temperature process and the properties are easy to change by varying the deposition parameters. So-prepared ZnO particles were then characterized using scanning electron microscope, X-ray diffraction, PL spectroscopy and UV-Vis optical absorption spectra. The XRD pattern of a typical ZnO structures grown using wet-chemical process exhibit sharp diffraction peaks characteristic of the ZnO wurtzite hexagonal phase (wurtzite-type, space group P63mc, JCPDS card file No. 36-1451). SEM image confirm the hexagonal ZnO structure. The UV-vis absorption spectra of ZnO structures show that samples prepared at high pH value demonstrated similar properties as bulk materials. It was also found that energy band gap (Eg) does not increase significantly with the increase in molar concentration of reactant solution. The PL measurement depicts that the relative intensity difference between UV emission and green emission in ZnO generally depends on the process condition, particle size, source materials, and synthesis method. The characteristic emissions were found to be extremely broad and this broadening may be due to photon assisted by phonon transition.