Exciton spectra of the nanostructured zinc oxide

Abstract

A simple two-step approach to produce ZnO nanorods and nanotubes by electron sputtering of the metallic zinc in vacuum and then oxidizing it to ZnO in air is reported. It has been found that the samples synthesised by this method exhibited much more intense exciton photoluminescence around ∼370 nm in comparison with the usual flat zinc oxide thin films. The clearly distinguished bands corresponding to localised exciton states and phonon replicas testify to quite high crystallinity of the obtained nanorods (nanotubes). The slight but noticeable blueshift (4 meV) in the near band edge luminescence for the sample with nanotubes in comparison with the samples with nanorods and flat films could reflect the quantum confinement effect.