title: Quenching of the luminescence intensity of GaN nanowires under electron beam exposure: impact of C adsorption on the exciton lifetime.
abstract: Electron irradiation of GaN nanowires in a scanning electron microscope strongly reduces their luminous efficiency as shown by cathodoluminescence imaging and spectroscopy. We demonstrate that this luminescence quenching originates from a combination of charge trapping at already existing surface states and the formation of new surface states induced by the adsorption of C on the nanowire sidewalls. The interplay of these effects leads to a complex temporal evolution of the quenching, which strongly depends on the incident electron dose per area. Time-resolved photoluminescence measurements on electron-irradiated samples reveal that the carbonaceous adlayer affects both the nonradiative and the radiative recombination dynamics.
authors.forename: Jonas
authors.initials: J
authors.lastname: Lähnemann
authors.forename: Timur
authors.initials: T
authors.lastname: Flissikowski
authors.forename: Martin
authors.initials: M
authors.lastname: Wölz
authors.forename: Lutz
authors.initials: L
authors.lastname: Geelhaar
authors.forename: Holger T
authors.initials: HT
authors.lastname: Grahn
authors.forename: Oliver
authors.initials: O
authors.lastname: Brandt
authors.forename: Uwe
authors.initials: U
authors.lastname: Jahn