Fabrication of ZnO hybrid structures and light emitting diode applications

Vertically-aligned ZnO nanorod arrays with a diameter of 40-150 nm were fabricated on Al₂O₃ substrates with and without GaN interlayers, and consequently covered with a ZnO film in-situ by a catalyst-free metal-organic chemical vapor deposition method. X-ray diffraction and transmission electron microscopy measurements demonstrated that the ZnO film/nanorods hybrid structures had a well-ordered wurtzite structure with no lattice mismatch between the film and nanorods, and that the film was homoepitaxially grown horizontally as well as vertically on the pre-grown nanorods. From n-ZnO film/nanorods/p-GaN hetero-junctions, we observed an asymmetry rectifying behavior.