title: Unexpected optical response of single ZnO nanowires probed using controllable electrical contacts.
abstract: Relying on combined electron-beam lithography and lift-off methods Au/Ti bilayer electrical contacts were attached to individual ZnO nanowires (NWs) that were grown by a vapor phase deposition method. Reliable Schottky-type as well as ohmic contacts were obtained depending on whether or not an ion milling process was used. The response of the ZnO NWs to ultraviolet light was found to be sensitive to the type of contacts. The intrinsic electronic properties of the ZnO NWs were studied in a field-effect transistor configuration. The transfer characteristics, including gate threshold voltage, hysteresis and operational mode, were demonstrated to unexpectedly respond to visible light. The origin of this effect could be accounted for by the presence of point defects in the ZnO NWs.
authors.affiliation: Laboratory of Solid-State Physics and Magnetism, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, BE-3001 Leuven, Belgium. yujia.zeng@fys.kuleuven.be
authors.forename: Y J
authors.initials: YJ
authors.lastname: Zeng
authors.forename: M
authors.initials: M
authors.lastname: Menghini
authors.forename: D Y
authors.initials: DY
authors.lastname: Li
authors.forename: S S
authors.initials: SS
authors.lastname: Lin
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Ye
authors.forename: J
authors.initials: J
authors.lastname: Hadermann
authors.forename: T
authors.initials: T
authors.lastname: Moorkens
authors.forename: J W
authors.initials: JW
authors.lastname: Seo
authors.forename: J-P
authors.initials: JP
authors.lastname: Locquet
authors.forename: C
authors.initials: C
authors.lastname: Van Haesendonck