Ultrasonic synthesis of ZnO nano/micro structures and their photoluminescence property

Abstract

A facile and environment-friendly ultrasonic route, to synthesize well-defined nearly spherical shape ZnO nanoparticles and spindle shape ZnO microrods, has been reported. The phase and structural analysis carried out by X-ray diffraction, confirmed the formation of hexagonal wurtzite structure of ZnO. Morphological studies carried out by electron microscope techniques, showed the formation of spherical shape ZnO nanoparticles in the absence of surfactant while spindle shape ZnO microrods in the presence of surfactant, under similar experimental conditions. Transmission electron microscope study showed that as prepared ZnO structures were single crystalline in nature and preferentially grew along [0001] direction. Furthermore, the optical property investigated by photoluminescence spectroscopy, showed only UV emission in case of ZnO nanoparticles where as UV as well as deep level emission in ZnO microrods. The origin of deep level emission in ZnO microrods was related to the structural defects of ZnO microcrystal.