title: Cathodoluminescence spectra of gallium nitride nanorods.
abstract: Gallium nitride [GaN] nanorods grown on a Si(111) substrate at 720°C via plasma-assisted molecular beam epitaxy were studied by field-emission electron microscopy and cathodoluminescence [CL]. The surface topography and optical properties of the GaN nanorod cluster and single GaN nanorod were measured and discussed. The defect-related CL spectra of GaN nanorods and their dependence on temperature were investigated. The CL spectra along the length of the individual GaN nanorod were also studied. The results reveal that the 3.2-eV peak comes from the structural defect at the interface between the GaN nanorod and Si substrate. The surface state emission of the single GaN nanorod is stronger as the diameter of the GaN nanorod becomes smaller due to an increased surface-to-volume ratio.
authors.affiliation: Department of Physics and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan, 80424, Republic of China. lwtu@faculty.nsysu.edu.tw.
authors.forename: Chia-Chang
authors.initials: CC
authors.lastname: Tsai
authors.forename: Guan-Hua
authors.initials: GH
authors.lastname: Li
authors.forename: Yuan-Ting
authors.initials: YT
authors.lastname: Lin
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Chang
authors.forename: Paritosh
authors.initials: P
authors.lastname: Wadekar
authors.forename: Quark Yung-Sung
authors.initials: QY
authors.lastname: Chen
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Rigutti
authors.forename: Maria
authors.initials: M
authors.lastname: Tchernycheva
authors.forename: François Henri
authors.initials: FH
authors.lastname: Julien
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Tu