title: Controllable dimension of ZnO nanowalls on GaN/c-Al2O3 substrate by vapor phase epitaxy method.
abstract: Vertically well-aligned ZnO nanowalls were successfully synthesized at 950-1050 degrees C. Ar gas was introduced into the furnace at a flow rate of 2000-2500 sccm. An Au thin film with a thickness of 3 nm was used as a catalyst. The ZnO nanowalls were successfully grown on the substrate and most of them had nearly the same thickness and were oriented perpendicular to the substrate. The morphology and chemical composition of the ZnO nanowalls were examined as a function of the growth conditions examined. It was found that the grown ZnO nanowalls have a single-crystalline hexagonal structure and preferred c-axis growth orientation based on the X-ray diffraction and high-resolution transmission electron microscope measurements. The room temperature photoluminescence showed a strong free-exciton emission band with negligible deep level emission, indicating the high optical property of our ZnO nanowall samples.
authors.affiliation: Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: W Y
authors.initials: WY
authors.lastname: Song
authors.forename: T I
authors.initials: TI
authors.lastname: Shin
authors.forename: S M
authors.initials: SM
authors.lastname: Kang
authors.forename: S W
authors.initials: SW
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Yang
authors.forename: M H
authors.initials: MH
authors.lastname: Park
authors.forename: C W
authors.initials: CW
authors.lastname: Yang
authors.forename: D H
authors.initials: DH
authors.lastname: Yoon
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D003460:Crystallization; D004867:Equipment Design; D005708:Gallium / Q000737:chemistry*; D049449:Luminescence; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D013499:Surface Properties; D013696:Temperature; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: C473348:gallium nitride; D005708:Gallium; D000537:Aluminum Oxide; D015034:Zinc Oxide