title: Unpredicted nucleation of extended zinc blende phases in wurtzite ZnO nanotetrapod arms.
abstract: Tailoring the structural and electronic properties of 3D nanostructures via bottom-up techniques would pave the way for novel low-cost applications. One of such possibilities is offered by ZnO branched nanostructures like tetrapods, that have recently attracted attention for nanodevice applications from nanoelectronics to drug delivery. The conventional picture is that ZnO arms are thermodynamically stable only in the wurtzite phase. Here, we provide the first experimental evidence of unpredicted extended zinc blend phases (50-60 nm long) embedded in the arms of ZnO wurtzite tetrapods. In particular, decisive evidence is obtained from the one-to-one correlation between high lateral resolution cathodoluminescence spectroscopy, monochromatic contrast maps, and atomic resolution transmission electron microscopy images of ZnO single TPs. This observation is not specific to ZnO and can have a general validity for the understanding of the nucleation mechanisms in semiconducting 3D nanostructures for device applications.
authors.affiliation: CNR-IMEM, University Campus, Viale G.P. Usberti 37/A, 43100 Parma, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Lazzarini
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Salviati
authors.forename: Filippo
authors.initials: F
authors.lastname: Fabbri
authors.forename: Mingzheng
authors.initials: M
authors.lastname: Zha
authors.forename: Davide
authors.initials: D
authors.lastname: Calestani
authors.forename: Andrea
authors.initials: A
authors.lastname: Zappettini
authors.forename: Takashi
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dierre