title: Solution grown ultra-violet emitting quasi-aligned ZnO nanotubes.
abstract: Quasi-aligned ZnO nanotubes were grown in a high density on Si substrate via aqueous solution method at low temperature of 65 degrees C by using zinc nitrate and hexamethylenetetramine. The detailed structural characterizations revealed that the as-synthesized nanotubes are single-crystalline possessing a hexagonal phase and grown along the [0001] direction. Raman-scattering spectrum exhibits a strong and sharp optical-phonon E2 high-mode at 437 cm(-1) again confirming the good crystal quality with hexagonal crystal structure for the as-synthesized nanotubes. A strong ultraviolet (UV) emission with a weak and broad orange is observed from the room-temperature photoluminescence (PL) spectrum which substantiates the good optical properties for the as-grown nanotubes. The detailed growth mechanism has also been proposed for the formation of as-grown nanotubes based on chemical reactions involved and different crystallographic habits of wurtzite hexagonal ZnO.
authors.affiliation: School of Semiconductor and Chemical Engineering, and BK 21, Centre for Future Energy Materials and Devices, Chonbuk National University, Jeonju, South Korea 561-756.
authors.forename: Y K
authors.initials: YK
authors.lastname: Park
authors.forename: Ahmad
authors.initials: A
authors.lastname: Umar
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: Yoon-Bong
authors.initials: YB
authors.lastname: Hahn