Vertically well aligned ZnO nanorod arrays with a diameter of 50 – 150 nm were fabricated on Al2O3 substrates with and without GaN interlayers, and consequently covered with a crystalline ZnO film in-situ by a catalyst-free metal-organic vapor-phase epitaxy (MOVPE) method. X-ray diffraction and field-emission transmission electron microscopy measurements revealed that the ZnO film/nanorods formed a single crystal with a WZ structure and lattice constant c of 5.2055 Å, which corresponded well with that of bulk ZnO. Neither extra superlattice reflection nor lattice mismatch between the ZnO film and nanorods was observed, implying the epitaxial growth of the ZnO film on the pre-grown ZnO nanorods. The surface roughness of the ZnO film/nanorods hybrid structures was determined to be about 3.0 nm by atomic force microscopy measurements. From n-ZnO film/nanorods/p-GaN heterojunctions, we observed a blue light emission with a wavelength of about 440 nm.
Journal: TechConnect Briefs
Volume: 1, Technical Proceedings of the 2007 NSTI Nanotechnology Conference and Trade Show, Volume 1
Published: May 20, 2007
Pages: 422 - 425
Industry sector: Advanced Materials & Manufacturing
Topics: Advanced Materials for Engineering Applications