Photoluminescence of ZnO Fine Powders Synthesized by Sol-Gel Process

Abstract

ZnO powder, which was composed of sub-micrometer particles, was synthesized by sol-gel method. SEM image shows that the mean size of the particles was about 70 nm. X-ray diffraction patterns revealed that the particles had hexagonal structure with the c-axis and a-axis lattice constants of 0.520 nm and 0.324 nm, respectively. The lattice constants are in well accordance with those of ZnO single crystal. Photoluminescence spectra at room temperature showed the green emission with the peak at 500 nm. In addition, the intensity of the green emission increased upon increasing the heating temperature.