Microstructural aspects for defect emission and E2high phonon mode of ZnO thin films

The ZnO thin films were prepared using a cost-effective vacuum-carbon-arc technique combined with thermal oxidation under ambient conditions from zinc nanoparticles in carbon matrix. The microstructural analysis of grazing incidence x-ray diffraction pattern using Rietveld method was investigated systematically under the influence of different annealing temperature. Photoluminescence spectroscopic properties of the samples studied at room temperature exhibits the dependence of violet emission accompanying with blue and green emission on oxidation temperature. The origin of defect emission mechanism through the microstructure of ZnO thin films was analyzed. The anharmonic properties of the upper E-2 phonon mode were investigated using Raman scattering spectroscopy at room temperature. The downshift of phonon frequency and linewidth broadening of high frequency E-2 phonon mode were analyzed through defect state according to annealed conditions. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3149786]