Solid State Reaction to Form Metal Oxide Heterostructure Nanowire

ZnO nanostructure has been investigated extensively due to its fascinating functional properties. ZnO heterostructure especially attracts a lot attention owing to various kinds of applications such as light-emitting device, resistive random-access memory, and solar cell. In this study, we deposited few nanometer of Al onto ZnO nanowire by electron beam evaporator, and successfully transformed ZnO nanowires into Al₂O₃/ZnO axial heterostructure. This reaction was occurred through solid state reaction at 700˚C in ultrahigh vacuum transmission electron microscope (UHV-TEM). We directly observed diffusion process during heating; in addition, the analysis of the kinetic behavior was carried out through the in situ video. The structure and composition were also identified by energy dispersive spectrometry (EDS) and Cs-corrected STEM. This research provide a method to fabricate a new type of one dimensional Al₂O₃/ZnO axial heterostructure, which may be applied in opto-electrical device and nanosensors.