title: Growth mechanism and optical properties of aligned hexagonal ZnO nanoprisms synthesized by noncatalytic thermal evaporation.
abstract: Vertically aligned perfectly hexagonal-shaped ZnO nanoprisms have been grown on a Si(100) substrate via a noncatalytic thermal evaporation process by using metallic zinc powder in the presence of oxygen gas. The as-grown nanoprisms consist of ultra smooth Zn-terminated (0001) facets bounded with the {0110} surfaces. The as-synthesized products are single-crystalline with the wurtzite hexagonal phase and grown along the [0001] direction, as confirmed from the detailed structural investigations. The presence of a sharp and strong nonpolar optical phonon high-E2 mode at 437 cm(-1) in the Raman scattering spectrum further confirms good crystallinity and wurtzite hexagonal phase for the as-grown products. The as-grown nanoprisms exhibit a strong near-band-edge emission with a very weak deep-level emission in the room-temperature and low-temperature photoluminescence measurements, confirming good optical properties for the deposited products. Moreover, systematic time-dependent experiments were also performed to determine the growth process of the grown vertically aligned nanoprisms.
authors.affiliation: School of Semiconductor and Chemical Engineering, BK21 Centre for Future Energy Materials and Devices, Semiconductor Physics Research Centre, Chonbuk National University, Jeonju 561-756, South Korea. ahmadumar@chonbuk.ac.kr.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Umar
authors.forename: B
authors.initials: B
authors.lastname: Karunagaran
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: E-K
authors.initials: EK
authors.lastname: Suh
authors.forename: Y B
authors.initials: YB
authors.lastname: Hahn
mesh_terms: D001151:Arsenic / Q000737:chemistry; D002384:Catalysis; D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D013053:Spectrophotometry; D013059:Spectrum Analysis, Raman; D013696:Temperature; D014835:Volatilization; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D001151:Arsenic; D015034:Zinc Oxide