Preparation and Photoluminescence of ZnO Nanorods Arrays

A high-density well-aligned Zinc Oxide nanorod array was synthesized on Si (100) substrate by a simplevapor deposition under normal pressure using neither a catalyst and nor pre-deposition of ZnO film. Various different morphologies were obtained in different deposition regions. Si substrate put over the Zn source was the key factor in getting a well-aligned sample. Field emission scanning electron microscope (FESEM) observations and X-ray diffraction were carried out to characterize the surface morphology and crystalline quality of the samples. The growth mechanism is discussed. The photoluminescence properties of the ZnO samples were also investigated. It is suggested that the green band is related to oxygen vacancies and thekinetic process involving transition from shallow donor to deep acceptor level.