Homoepitaxial ZnO film growth on vertically aligned ZnO nanorods

We present a 2D ZnO film epitaxially grown on 1D ZnO nanorods with catalyst-free metal-organic chemical vapor deposition. Vertically aligned ZnO nanorods were synthesized on Al2O3Al2O3 substrates, and subsequently, a ZnO film was deposited on the pre-grown ZnO nanorods in situ. The dimensional ZnO growth was controlled by the growth chamber pressure. High-resolution X-ray diffraction and field-emission transmission electron microscope measurements demonstrated that the ZnO film was epitaxially grown on the pre-grown ZnO nanorods, and that the ZnO film/nanorods structures had a well-ordered wurtzite structure. The ZnO film on ZnO nanorods/Al2O3 had a uniform thickness with an average minimum thickness of 0.25μm and the root-mean-square roughness of 3 nm determined by Filed-emission scanning electron microscope and an atomic force microscopy measurements, respectively. These ZnO film/nanorods hybrid structures can be used as nanobuilding blocks for nanodevice applications.