Novel approach for observing the asymmetrical evolution and the compositional nonuniformity of laser pulsed atom probe tomography of a single ZnO nanowire

Abstract

The characterization of ZnO nanowires is crucial for developing nanostructured devices together with related compounds and alloys with an atomic-scale regime. This study describes the effects of laser energy on the atom probe tomography analysis of a single ZnO nanowire with a high aspect ratio, diameters of 80−100 nm and lengths of 10 μm. We observed both an asymmetrical evolution in the apex morphology and the compositional nonuniformities of Zn and O ions with respect to the laser energies ranging from 5 to 40 nJ. When the higher laser illumination exposed to the ZnO nanowires, non-uniform field strength becomes noticeable especially at the laser incident side of the samples. Moreover, we measured the charge state ratios of Zn + and Zn 2+ ions as a function of the applied laser energies. Our results proved important for accurate quantitative characterization and better interpretation for the laser-pulsed atom probe tomography of ZnO-based devices.