title: Unintentional high-density p-type modulation doping of a GaAs/AlAs core-multishell nanowire.
abstract: Achieving significant doping in GaAs/AlAs core/shell nanowires (NWs) is of considerable technological importance but remains a challenge due to the amphoteric behavior of the dopant atoms. Here we show that placing a narrow GaAs quantum well in the AlAs shell effectively getters residual carbon acceptors leading to an unintentional p-type doping. Magneto-optical studies of such a GaAs/AlAs core-multishell NW reveal quantum confined emission. Theoretical calculations of NW electronic structure confirm quantum confinement of carriers at the core/shell interface due to the presence of ionized carbon acceptors in the 1 nm GaAs layer in the shell. Microphotoluminescence in high magnetic field shows a clear signature of avoided crossings of the n = 0 Landau level emission line with the n = 2 Landau level TO phonon replica. The coupling is caused by the resonant hole-phonon interaction, which points to a large two-dimensional hole density in the structure.
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA , 143, avenue de Rangueil, 31400 Toulouse, France.
authors.forename: J
authors.initials: J
authors.lastname: Jadczak
authors.forename: P
authors.initials: P
authors.lastname: Plochocka
authors.forename: A
authors.initials: A
authors.lastname: Mitioglu
authors.forename: I
authors.initials: I
authors.lastname: Breslavetz
authors.forename: M
authors.initials: M
authors.lastname: Royo
authors.forename: A
authors.initials: A
authors.lastname: Bertoni
authors.forename: G
authors.initials: G
authors.lastname: Goldoni
authors.forename: T
authors.initials: T
authors.lastname: Smolenski
authors.forename: P
authors.initials: P
authors.lastname: Kossacki
authors.forename: A
authors.initials: A
authors.lastname: Kretinin
authors.forename: Hadas
authors.initials: H
authors.lastname: Shtrikman
authors.forename: D K
authors.initials: DK
authors.lastname: Maude