title: Photoluminescence of GaN nanowires of different crystallographic orientations.
abstract: We utilized time-integrated and time-resolved photoluminescence of a-axis and c-axis gallium nitride nanowires to elucidate the origin of the blue-shifted ultraviolet photoluminescence in a-axis GaN nanowires relative to c-axis GaN nanowires. We attribute this blue-shifted ultraviolet photoluminescence to emission from surface trap states as opposed to previously proposed causes such as strain effects or built-in polarization. These results demonstrate the importance of accounting for surface effects when considering ultraviolet optoelectronic devices based on GaN nanowires.
authors.affiliation: Center for Advanced Aerospace Materials and Devices, NASA Ames Research Center, Moffett Field, California 94035, USA. achin@mail.arc.nasa.gov
authors.forename: Alan H
authors.initials: AH
authors.lastname: Chin
authors.forename: Tai S
authors.initials: TS
authors.lastname: Ahn
authors.forename: Hongwei
authors.initials: H
authors.lastname: Li
authors.forename: Sreeram
authors.initials: S
authors.lastname: Vaddiraju
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Bardeen
authors.forename: Cun-Zheng
authors.initials: CZ
authors.lastname: Ning
authors.forename: Mahendra K
authors.initials: MK
authors.lastname: Sunkara